Charge transfer to ground-state ions produces free electrons
You, D.; Fukuzawa, H.; Sakakibara, Y.; Takanashi, T.; Ito, Y.; Maliyar, G. G.; Motomura, K.; Nagaya, K.; Nishiyama, T.; Asa, K.; Sato, Y.; Saito, N.; Oura, M.; Schöffler, M.; Kastirke, G.; Hergenhahn, U.; Stumpf, V.; Gokhberg, K.; Kuleff, A. I.; Cederbaum, L. S.; Ueda, K.
2017-01-01
Inner-shell ionization of an isolated atom typically leads to Auger decay. In an environment, for example, a liquid or a van der Waals bonded system, this process will be modified, and becomes part of a complex cascade of relaxation steps. Understanding these steps is important, as they determine the production of slow electrons and singly charged radicals, the most abundant products in radiation chemistry. In this communication, we present experimental evidence for a so-far unobserved, but potentially very important step in such relaxation cascades: Multiply charged ionic states after Auger decay may partially be neutralized by electron transfer, simultaneously evoking the creation of a low-energy free electron (electron transfer-mediated decay). This process is effective even after Auger decay into the dicationic ground state. In our experiment, we observe the decay of Ne2+ produced after Ne 1s photoionization in Ne-Kr mixed clusters.
Charge transfer to ground-state ions produces free electrons
You, D.; Fukuzawa, H.; Sakakibara, Y.; Takanashi, T.; Ito, Y.; Maliyar, G. G.; Motomura, K.; Nagaya, K.; Nishiyama, T.; Asa, K.; Sato, Y.; Saito, N.; Oura, M.; Schöffler, M.; Kastirke, G.; Hergenhahn, U.; Stumpf, V.; Gokhberg, K.; Kuleff, A. I.; Cederbaum, L. S.; Ueda, K
2017-01-01
Inner-shell ionization of an isolated atom typically leads to Auger decay. In an environment, for example, a liquid or a van der Waals bonded system, this process will be modified, and becomes part of a complex cascade of relaxation steps. Understanding these steps is important, as they determine the production of slow electrons and singly charged radicals, the most abundant products in radiation chemistry. In this communication, we present experimental evidence for a so-far unobserved, but potentially very important step in such relaxation cascades: Multiply charged ionic states after Auger decay may partially be neutralized by electron transfer, simultaneously evoking the creation of a low-energy free electron (electron transfer-mediated decay). This process is effective even after Auger decay into the dicationic ground state. In our experiment, we observe the decay of Ne2+ produced after Ne 1s photoionization in Ne–Kr mixed clusters. PMID:28134238
Ground-state charge transfer as a mechanism for surface-enhanced Raman scattering
Lippitsch, Max E.
1984-03-01
A model is presented for the contribution of ground-state charge transfer between a metal and adsorbate to surface-enhanced Raman scattering (SERS). It is shown that this contribution can be understood using the vibronic theory for calculating Raman intensities. The enhancement is due to vibronic coupling of the molecular ground state to the metal states, the coupling mechanism being a modulation of the ground-state charge-transfer energy by the molecular vibrations. An analysis of the coupling operator gives the selection rules for this process, which turn out to be dependent on the overall symmetry of the adsorbate-metal system, even if the charge transfer is small enough for the symmetry of the adsorbate to remain the same as that of the free molecule. It is shown that the model can yield predictions on the properties of SERS, e.g., specificity to adsorption geometry, appearance of forbidden bands, dependence on the applied potential, and dependence on the excitation wavelength. The predictions are in good agreement with experimental results. It is also deduced from this model that in many cases atomic-scale roughness is a prerequisite for the observation of SERS. A result on the magnitude of the enhancement can only be given in a crude approximation. Although in most cases an additional electromagnetic enhancement seems to be necessary to give an observable signal, this charge-transfer mechanism should be important in many SERS systems.
Semilocal and Hybrid Density Embedding Calculations of Ground-State Charge-Transfer Complexes
Laricchia, S; Della Sala, F; 10.1063/1.4795825
2013-01-01
We apply the frozen density embedding method, using a full relaxation of embedded densities through a freeze-and-thaw procedure, to study the electronic structure of several benchmark ground-state charge-transfer complexes, in order to assess the merits and limitations of the approach for this class of systems. The calculations are performed using both semilocal and hybrid exchange-correlation (XC) functionals. The results show that embedding calculations using semilocal XC functionals yield rather large deviations with respect to the corresponding supermolecular calculations. Due to a large error cancellation effect, however, they can often provide a relatively good description of the electronic structure of charge-transfer complexes, in contrast to supermolecular calculations performed at the same level of theory. On the contrary, when hybrid XC functionals are employed, both embedding and supermolecular calculations agree very well with each other and with the reference benchmark results. In conclusion, fo...
Lackner, Klaus S.; Zweig, George
1987-09-01
The arguments presented in the Comment by Liebman and Huheey are shown to be incorrect. The operational equivalence of Mulliken ground-state electronegativities and Pauling electronegativities is demonstrated for neutral atoms. It is shown that ground-state electronegativities and valence-state electronegativities for both neutral atoms and ions are also operationally equivalent. A single electronegativity scale based on Mulliken ground-state electronegativities may therefore be used for neutral atoms, ions, and fractionally charged atoms, as originally implied in the paper by Lackner and Zweig.
Ghosh, Soumen; Sonnenberger, Andrew L; Hoyer, Chad E; Truhlar, Donald G; Gagliardi, Laura
2015-08-11
The correct description of charge transfer in ground and excited states is very important for molecular interactions, photochemistry, electrochemistry, and charge transport, but it is very challenging for Kohn-Sham (KS) density functional theory (DFT). KS-DFT exchange-correlation functionals without nonlocal exchange fail to describe both ground- and excited-state charge transfer properly. We have recently proposed a theory called multiconfiguration pair-density functional theory (MC-PDFT), which is based on a combination of multiconfiguration wave function theory with a new type of density functional called an on-top density functional. Here we have used MC-PDFT to study challenging ground- and excited-state charge-transfer processes by using on-top density functionals obtained by translating KS exchange-correlation functionals. For ground-state charge transfer, MC-PDFT performs better than either the PBE exchange-correlation functional or CASPT2 wave function theory. For excited-state charge transfer, MC-PDFT (unlike KS-DFT) shows qualitatively correct behavior at long-range with great improvement in predicted excitation energies.
Ground State and Charge Renormalization in a Nonlinear Model of Relativistic Atoms
Gravejat, Philippe; Sere, Eric
2007-01-01
We study the reduced Bogoliubov-Dirac-Fock (BDF) energy which allows to describe relativistic electrons interacting with the Dirac sea, in an external electrostatic potential. The model can be seen as a mean-field approximation of Quantum Electrodynamics (QED) where photons and the so-called exchange term are neglected. A state of the system is described by its one-body density matrix, an infinite rank self-adjoint operator which is a compact perturbation of the negative spectral projector of the free Dirac operator (the Dirac sea). We study the minimization of the reduced BDF energy under a charge constraint. We prove the existence of minimizers for a large range of values of the charge, and any positive value of the coupling constant $\\alpha$. Our result covers neutral and positively charged molecules, provided that the positive charge is not large enough to create electron-positron pairs. We also prove that the density of any minimizer is an $L^1$ function and compute the effective charge of the system, re...
Tan, B S; Harrison, N; Zhu, Z; Balakirev, F; Ramshaw, B J; Srivastava, A; Sabok-Sayr, S A; Sabok, S A; Dabrowski, B; Lonzarich, G G; Sebastian, Suchitra E
2015-08-04
The normal state in the hole underdoped copper oxide superconductors has proven to be a source of mystery for decades. The measurement of a small Fermi surface by quantum oscillations on suppression of superconductivity by high applied magnetic fields, together with complementary spectroscopic measurements in the hole underdoped copper oxide superconductors, point to a nodal electron pocket from charge order in YBa2Cu3(6+δ). Here, we report quantum oscillation measurements in the closely related stoichiometric material YBa2Cu4O8, which reveals similar Fermi surface properties to YBa2Cu3(6+δ), despite the nonobservation of charge order signatures in the same spectroscopic techniques, such as X-ray diffraction, that revealed signatures of charge order in YBa2Cu3(6+δ). Fermi surface reconstruction in YBa2Cu4O8 is suggested to occur from magnetic field enhancement of charge order that is rendered fragile in zero magnetic fields because of its potential unconventional nature and/or its occurrence as a subsidiary to more robust underlying electronic correlations.
Geng, L S; Meng, J
2005-01-01
We perform a systematic study of the ground-state properties of all the nuclei from the proton drip line to the neutron drip line throughout the periodic table employing the relativistic mean field model. The TMA parameter set is used for the mean-field Lagrangian density, and a state-dependent BCS method is adopted to describe the pairing correlation. The ground-state properties of a total of 6969 nuclei with $Z,N\\ge 8$ and $Z\\le 100$ from the proton drip line to the neutron drip line, including the binding energies, the separation energies, the deformations, and the rms charge radii, are calculated and compared with existing experimental data and those of the FRDM and HFB-2 mass formulae. This study provides the first complete picture of the current status of the descriptions of nuclear ground-state properties in the relativistic mean field model. The deviations from existing experimental data indicate either that new degrees of freedom are needed, such as triaxial deformations, or that serious effort is ne...
Andrianarijaona, V. M.; King, J. G.; Martin, M. F.; de Ruette, N.; Urbain, X.
2013-05-01
We investigated the charge transfer (CT) from an H2 or D2 target to various fast atomic/molecular ions for a wide span of collision energies in the laboratory frame (eV to keV). Vibrationally resolved cross sections have been obtained on a relative scale, by dissociative charge transfer of the product H2+ ions with potassium atoms, and 3-D imaging of the fragments. An absolute value of the total CT cross section has been inferred from the measured ratio of the CT yield for protons and H2+, combined with the recommended H2+ + H2 cross section (ORNL). Our results on the (H2, H+) system benchmark state-to-state calculations at 10eV and above (Phys. Rev. A 75 032703, 2007 and J. Phys. B 42, 105207 2009). In particular, they confirm the vibrational excitation mechanism responsible for the resonance at 50eV, characterized by a dominant population of the ground vibrational state of H2++. The spectra for the isotopic system (D2, H+) will be also presented along with the results of CT performed with H2++ and D2+ projectiles. Research supported by the Fund for Scientific Research - FNRS through IISN Grant No. 4.4504.10, and the National Science Foundation through Grant No. PHY-106887.
Miyagi, Takayuki; Okamoto, Ryoji; Otsuka, Takaharu
2015-01-01
We study the nuclear ground-state properties by using the unitary-model-operator approach (UMOA). Recently, the particle-basis formalism has been introduced in the UMOA and enables us to employ the charge-dependent nucleon-nucleon interaction. We evaluate the ground-state energies and charge radii of $^{4}$He, $^{16}$O, $^{40}$Ca, and $^{56}$Ni with the charge-dependent Bonn potential. The ground-state energy is dominated by the contributions from the one- and two-body cluster terms, while, for the radius, the one-particle-one-hole excitations are more important than the two-particle-two-hole excitations. The calculated results reproduce the trend of experimental data of the saturation property for finite nuclei.
JIN Jing; TANG Yi
2007-01-01
The diffusion Monte Carlo method is applied to study the ground-state properties of charged bosons in one dimension confined in a harmonic double-well trap. The particles interact repulsively through a Coulombic 1/r potential. Numerical results show that the well separation has significant influence on the ground-state properties of the system. When the interaction of the system is weak, ground-state energy decreases with the increasing well separation and has a minimal value. If the well separation increases continually, the ground-state energy increases and approaches to a constant gradually. This effect will be abatable in the strong interacting system. In addition,by calculating the density of the systems for different interaction strengths with various well separations, we find that the density increases abnormally when the well separation is large at the centre of the system.
Li, Hui; Schubert, Christina; Dral, Pavlo O; Costa, Rubén D; La Rosa, Andrea; Thüring, Jürg; Liu, Shi-Xia; Yi, Chenyi; Filippone, Salvatore; Martín, Nazario; Decurtins, Silvio; Clark, Timothy; Guldi, Dirk M
2013-09-16
Rigid electron donor-acceptor conjugates (1-3) that combine π-extended benzodifurans as electron donors and C60 molecules as electron acceptors with different linkers have been synthesized and investigated with respect to intramolecular charge-transfer events. Electrochemistry, fluorescence, and transient absorption measurements revealed tunable and structure-dependent charge-transfer processes in the ground and excited states. Our experimental findings are underpinned by density-functional theory calculations. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Tkalya, E V
2016-01-01
The magnetic hyperfine (MHF) structure of the $5/2^+$(0.0 eV) ground state and the low-lying $3/2^+$(7.8 eV) isomeric state of the $^{229}$Th nucleus in highly charged ions Th$^{89+}$ and Th$^{87+}$ is calculated. The distribution of the nuclear magnetization (the Bohr-Weisskopf effect) is accounted for in the framework of the collective nuclear model with the wave functions of the Nilsson model for the unpaired neutron. The deviations of the MHF structure for the ground and isomeric states from their values in the model of point-like nuclear magnetic dipole are calculated. The influence of the mixing of the states with the same quantum number $F$ on the energy of sublevels is studied. Taking into account the mixing of states, the probabilities of the transitions between the components of MHF structure are found.
Tkalya, E. V.; Nikolaev, A. V.
2016-07-01
Background: The search for new opportunities to investigate the low-energy level in the 229Th nucleus, which is nowadays intensively studied experimentally, has motivated us to theoretical studies of the magnetic hyperfine (MHF) structure of the 5 /2+ (0.0 eV) ground state and the low-lying 3 /2+ (7.8 eV) isomeric state in highly charged 89+229Th and 87+229Th ions. Purpose: The aim is to calculate, with the maximal precision presently achievable, the energy of levels of the hyperfine structure of the 229Th ground-state doublet in highly charged ions and the probability of radiative transitions between these levels. Methods: The distribution of the nuclear magnetization (the Bohr-Weisskopf effect) is accounted for in the framework of the collective nuclear model with Nilsson model wave functions for the unpaired neutron. Numerical calculations using precise atomic density functional theory methods, with full account of the electron self-consistent field, have been performed for the electron structure inside and outside the nuclear region. Results: The deviations of the MHF structure for the ground and isomeric states from their values in a model of a pointlike nuclear magnetic dipole are calculated. The influence of the mixing of the states with the same quantum number F on the energy of sublevels is studied. Taking into account the mixing of states, the probabilities of the transitions between the components of the MHF structure are calculated. Conclusions: Our findings are relevant for experiments with highly ionized 229Th ions in a storage ring at an accelerator facility.
Whitfield, J D; Biamonte, J D
2012-01-01
Designing and optimizing cost functions and energy landscapes is a problem encountered in many fields of science and engineering. These landscapes and cost functions can be embedded and annealed in experimentally controllable spin Hamiltonians. Using an approach based on group theory and symmetries, we examine the embedding of Boolean logic gates into the ground state subspace of such spin systems. We describe parameterized families of diagonal Hamiltonians and symmetry operations which preserve the ground state subspace encoding the truth tables of Boolean formulas. The ground state embeddings of adder circuits are used to illustrate how gates are combined and simplified using symmetry. Our work is relevant for experimental demonstrations of ground state embeddings found in both classical optimization as well as adiabatic quantum optimization.
Argument for charge density wave sub-phases in the ground state of α-(BEDT-TTF) 2KHg(SCN) 4
Biskup, N.; Perenboom, J. A. A. J.; Brooks, J. S.; Qualls, J. S.
1998-07-01
A resistive anomaly at temperature Tp in the title compound is associated with a Fermi surface reconstruction from a metallic to a (spin or charge) density wave state. At high magnetic fields a corresponding feature in the magnetoresistance above a field BK indicates the breaking of this state. We argue that TP indicates a second order phase line identical to that measured by specific heat methods and show that it decreases monotonically up to 30T. We find that Pauli (rather than orbital) effects, dominate the reduction in Tp. We further argue that BK is a first-order transition between two subphases below Tp. We compare the phase diagram with recent theoretical models for CDW and SDW ground states in high magnetic fields.
Heid, Esther; Harringer, Sophia; Schröder, Christian
2016-10-01
The influence of the partial charge distribution obtained from quantum mechanics of the solute 1-methyl-6-oxyquinolinium betaine in the ground- and first excited state on the time-dependent Stokes shift is studied via molecular dynamics computer simulation. Furthermore, the effect of the employed solvent model — here the non-polarizable SPC, TIP4P and TIP4P/2005 and the polarizable SWM4 water model — on the solvation dynamics of the system is investigated. The use of different functionals and calculation methods influences the partial charge distribution and the magnitude of the dipole moment of the solute, but not the orientation of the dipole moment. Simulations based on the calculated charge distributions show nearly the same relaxation behavior. Approximating the whole solute molecule by a dipole results in the same relaxation behavior, but lower solvation energies, indicating that the time scale of the Stokes shift does not depend on peculiarities of the solute. However, the SPC and TIP4P water models show too fast dynamics which can be ascribed to a too large diffusion coefficient and too low viscosity. The calculated diffusion coefficient and viscosity for the SWM4 and TIP4P/2005 models coincide well with experimental values and the corresponding relaxation behavior is comparable to experimental values. Furthermore we found that for a quantitative description of the Stokes shift of the applied system at least two solvation shells around the solute have to be taken into account.
Friesecke, Gero
2008-01-01
This paper is concerned with the Schr\\"odinger equation for atoms and ions with N=1 to 10 electrons. In the asymptotic limit of large nuclear charge $Z$, we determine explicitly the low-lying energy levels and eigenstates. The asymptotic energies and wavefunctions are in good quantitative agreement with experimental data for positive ions, and in excellent qualitative agreement even for neutral atoms ($Z=N$). In particular, the predicted ground state spin and angular momentum quantum numbers ($^1S$ for He, Be, Ne, $^2S$ for H and Li, $^4S$ for N, $^2P$ for B and F, and $^3P$ for C and O) agree with experiment in every case. The asymptotic Schr\\"odinger ground states agree, up to small corrections, with the semi-empirical hydrogen orbital configurations developed by Bohr, Hund and Slater to explain the periodic table. In rare cases where our results deviate from this picture, such as the ordering of the lowest ${}^1D^o$ and ${}^5S^o$ states of Carbon, experiment confirms our, not Hund's, predictions.
Lackner, K.S.; Zweig, G.
1987-09-01
The arguments presented in the Comment by Liebman and Huheey are shown to be incorrect. The operational equivalence of Mulliken ground-state electronegativities and Pauling electronegativities is demonstrated for neutral atoms. It is shown that ground-state electronegativities and valence-state electronegativities for both neutral atoms and ions are also operationally equivalent. A single electronegativity scale based on Mulliken ground-state electronegativities may therefore be used for neutral atoms, ions, and fractionally charged atoms, as originally implied in the paper by Lackner and Zweig.
Sini, Gjergji
2011-03-08
We have evaluated the performance of several density functional theory (DFT) functionals for the description of the ground-state electronic structure and charge transfer in donor/acceptor complexes. The tetrathiafulvalene- tetracyanoquinodimethane (TTF-TCNQ) complex has been considered as a model test case. Hybrid functionals have been chosen together with recently proposed long-range corrected functionals (ωB97X, ωB97X-D, LRC-ωPBEh, and LC-ωPBE) in order to assess the sensitivity of the results to the treatment and magnitude of exact exchange. The results show an approximately linear dependence of the ground-state charge transfer with the HOMO TTF-LUMOTCNQ energy gap, which in turn depends linearly on the percentage of exact exchange in the functional. The reliability of ground-state charge transfer values calculated in the framework of a monodeterminantal DFT approach was also examined. © 2011 American Chemical Society.
Bisogni, Valentina; Catalano, Sara; Green, Robert J.; Gibert, Marta; Scherwitzl, Raoul; Huang, Yaobo; Strocov, Vladimir N.; Zubko, Pavlo; Balandeh, Shadi; Triscone, Jean-Marc; Sawatzky, George; Schmitt, Thorsten
2016-10-01
The metal-insulator transition and the intriguing physical properties of rare-earth perovskite nickelates have attracted considerable attention in recent years. Nonetheless, a complete understanding of these materials remains elusive. Here we combine X-ray absorption and resonant inelastic X-ray scattering (RIXS) spectroscopies to resolve important aspects of the complex electronic structure of rare-earth nickelates, taking NdNiO3 thin film as representative example. The unusual coexistence of bound and continuum excitations observed in the RIXS spectra provides strong evidence for abundant oxygen holes in the ground state of these materials. Using cluster calculations and Anderson impurity model interpretation, we show that distinct spectral signatures arise from a Ni 3d8 configuration along with holes in the oxygen 2p valence band, confirming suggestions that these materials do not obey a conventional positive charge-transfer picture, but instead exhibit a negative charge-transfer energy in line with recent models interpreting the metal-insulator transition in terms of bond disproportionation.
Singlet Ground State Magnetism:
Loidl, A.; Knorr, K.; Kjems, Jørgen;
1979-01-01
The magneticGamma 1 –Gamma 4 exciton of the singlet ground state system TbP has been studied by inelastic neutron scattering above the antiferromagnetic ordering temperature. Considerable dispersion and a pronounced splitting was found in the [100] and [110] directions. Both the band width...... and the splitting increased rapidly as the transition temperature was approached in accordance with the predictions of the RPA-theory. The dispersion is analysed in terms of a phenomenological model using interactions up to the fourth nearest neighbour....
Shepard, K.W.; Kim, J.W.
1995-08-01
A design is being developed for a low-charge-state linac suitable for injecting ATLAS with a low-charge-state, radioactive beam. Initial work indicates that the existing ATLAS interdigital superconducting accelerating structures, together with the superconducting quadrupole transverse focussing element discussed above, provides a basis for a high-performance low-charge-state linac. The initial 2 or 3 MV of such a linac could be based on a normally-conducting, low-frequency RFQ, possibly combined with 24-MHz superconducting interdigital structures. Beam dynamics studies of the whole low-charge-state post-accelerator section were carried out in early FY 1995.
Thermal ground state and nonthermal probes
Grandou, Thierry
2015-01-01
The Euclidean formulation of SU(2) Yang-Mills thermodynamics admits periodic, (anti)selfdual solutions to the fundamental, classical equation of motion which possess one unit of topological charge: (anti)calorons. A spatial coarse graining over the central region in a pair of such localised field configurations with trivial holonomy generates an inert adjoint scalar field $\\phi$, effectively describing the pure quantum part of the thermal ground state in the induced quantum field theory. The latter's local vertices are mediated by just-not-resolved (anti)caloron centers of action $\\hbar$. This is the basic reason for a rapid convergence of the loop expansion of thermodynamical quantities, polarization tensors, etc., their effective loop momenta being severely constrained in entirely fixed and physical unitary-Coulomb gauge. Here we show for the limit of zero holonomy how (anti)calorons associate a temperature independent electric permittivity and magnetic permeability to the thermal ground state of SU(2)$_{\\t...
Thermodynamic Ground States of Complex Oxide Heterointerfaces
Gunkel, F.; Hoffmann-Eifert, S.; Heinen, R. A.
2017-01-01
The formation mechanism of 2-dimensional electron gases (2DEGs) at heterointerfaces between nominally insulating oxides is addressed with a thermodynamical approach. We provide a comprehensive analysis of the thermodynamic ground states of various 2DEG systems directly probed in high temperature...... equilibrium conductivity measurements. We unambiguously identify two distinct classes of oxide heterostructures: For epitaxial perovskite/perovskite heterointerfaces (LaAlO3/SrTiO3, NdGaO3/SrTiO3, and (La,Sr)(Al,Ta)O3/SrTiO3), we find the 2DEG formation being based on charge transfer into the interface...
Vitos, Levente; Kollár, J.; Skriver, Hans Lomholt
1997-01-01
We present a full charge-density technique to evaluate total energies from the output of self-consistent linear muffin-tin orbitals (LMTO) calculations in the atomic-sphere approximation (ASA). The Coulomb energy is calculated exactly from the complete, nonspherically symmetric charge density def...
Pieper, Steven C.; Wiringa, R. B.; Pandharipande, V. R.
1990-01-01
A variational method is used to study the ground state of 16O. Expectation values are computed with a cluster expansion for the noncentral correlations in the wave function; the central correlations and exchanges are treated to all orders by Monte Carlo integration. The expansion has good convergence. Results are reported for the Argonne v14 two-nucleon and Urbana VII three-nucleon potentials.
Ground-state structures of Hafnium clusters
Ng, Wei Chun; Yoon, Tiem Leong [School of Physics, Universiti Sains Malaysia, 11800 USM, Penang (Malaysia); Lim, Thong Leng [Faculty of Engineering and Technoloty, Multimedia University, Melaca Campus, 75450 Melaka (Malaysia)
2015-04-24
Hafnium (Hf) is a very large tetra-valence d-block element which is able to form relatively long covalent bond. Researchers are interested to search for substitution to silicon in the semi-conductor industry. We attempt to obtain the ground-state structures of small Hf clusters at both empirical and density-functional theory (DFT) levels. For calculations at the empirical level, charge-optimized many-body functional potential (COMB) is used. The lowest-energy structures are obtained via a novel global-minimum search algorithm known as parallel tempering Monte-Carlo Basin-Hopping and Genetic Algorithm (PTMBHGA). The virtue of using COMB potential for Hf cluster calculation lies in the fact that by including the charge optimization at the valence shells, we can encourage the formation of proper bond hybridization, and thus getting the correct bond order. The obtained structures are further optimized using DFT to ensure a close proximity to the ground-state.
Chen, Xian Kai
2016-09-05
In organic solar cells, a major source of energy loss is attributed to nonradiative recombination from the interfacial charge transfer states to the ground state. By taking pentacene–C60 complexes as model donor–acceptor systems, a comprehensive theoretical understanding of how molecular packing and charge delocalization impact these nonradiative recombination rates at donor–acceptor interfaces is provided.
Mihaila, Bogdan; Heisenberg, Jochen
2000-04-01
We continue the investigations of ground state properties of closed-shell nuclei using the Argonne v18 realistic NN potential, together with the Urbana IX three-nucleon interaction. The ground state wave function is used to calculate the charge form factor and charge density. Starting with the ground state wave function of the closed-shell nucleus, we use the equation of motion technique to calculate the ground state and excited states of a neighboring nucleus. We then generate the corresponding magnetic form factor. We correct for distortions due to the interaction between the electron probe and the nuclear Coulomb field using the DWBA picture. We compare our results with the available experimental data. Even though our presentation will focus mainly on the ^16O and ^15N nuclei, results for other nuclei in the p and s-d shell will also be presented.
A high charge state multicusp ion source
Leung, K.N.; Keller, R. (Accelerator and Fusion Research Division, Lawrence Berkeley Laboratory, 1 Cyclotron Road, Berkeley, California 94720 (US))
1990-01-01
Attempts have been made to generate high charge state ion beams by employing a multicusp plasma source. Three experimental investigations have been performed at Lawrence Berkeley Laboratory (LBL) and at Gesellschaft fuer Schwerionenforschung, Darmstadt (GSI) to study the charge state distributions and the emittance of the extracted beam. Results demonstrate that charge state as high as +7 can be obtained with argon or xenon plasmas. The brightness of a 11-mA xenon ion beam is found to be 26 A/({pi} mm mrad){sup 2}.
Shepard, K.W.; Kim, J.W.
1995-08-01
Preliminary design work was done for a short, normally-conducting RFQ entrance section for a low-charge-state linac. Early results indicate that a low- frequency (12 MHz) RFQ, operated on a high-voltage platform, and injected with a pre-bunched beam, can provide ATLAS quality beams of ions of charge-to-mass ratio less than 1/132.
Coherent States with SU(N) Charges
Mathur, M; Mathur, Manu; Paul, Samir K.
2003-01-01
We define coherent states carrying SU(N) charges by exploiting generalized Schwinger boson representation of SU(N) Lie algebra. These coherent states are defined on $2 (2^{N - 1} - 1)$ complex planes. They satisfy continuity property and provide resolution of identity. We also exploit this technique to construct the corresponding non-linear SU(N) coherent states.
Langevin equation path integral ground state.
Constable, Steve; Schmidt, Matthew; Ing, Christopher; Zeng, Tao; Roy, Pierre-Nicholas
2013-08-15
We propose a Langevin equation path integral ground state (LePIGS) approach for the calculation of ground state (zero temperature) properties of molecular systems. The approach is based on a modification of the finite temperature path integral Langevin equation (PILE) method (J. Chem. Phys. 2010, 133, 124104) to the case of open Feynman paths. Such open paths are necessary for a ground state formulation. We illustrate the applicability of the method using model systems and the weakly bound water-parahydrogen dimer. We show that the method can lead to converged zero point energies and structural properties.
Electronically shielded solid state charged particle detector
Balmer, D.K.; Haverty, T.W.; Nordin, C.W.; Tyree, W.H.
1996-08-20
An electronically shielded solid state charged particle detector system having enhanced radio frequency interference immunity includes a detector housing with a detector entrance opening for receiving the charged particles. A charged particle detector having an active surface is disposed within the housing. The active surface faces toward the detector entrance opening for providing electrical signals representative of the received charged particles when the received charged particles are applied to the active surface. A conductive layer is disposed upon the active surface. In a preferred embodiment, a nonconductive layer is disposed between the conductive layer and the active surface. The conductive layer is electrically coupled to the detector housing to provide a substantially continuous conductive electrical shield surrounding the active surface. The inner surface of the detector housing is supplemented with a radio frequency absorbing material such as ferrite. 1 fig.
Electronically shielded solid state charged particle detector
Balmer, David K. (155 Coral Way, Broomfield, CO 80020); Haverty, Thomas W. (1173 Logan, Northglenn, CO 80233); Nordin, Carl W. (7203 W. 32nd Ave., Wheatridge, CO 80033); Tyree, William H. (1977 Senda Rocosa, Boulder, CO 80303)
1996-08-20
An electronically shielded solid state charged particle detector system having enhanced radio frequency interference immunity includes a detector housing with a detector entrance opening for receiving the charged particles. A charged particle detector having an active surface is disposed within the housing. The active surface faces toward the detector entrance opening for providing electrical signals representative of the received charged particles when the received charged particles are applied to the active surface. A conductive layer is disposed upon the active surface. In a preferred embodiment, a nonconductive layer is disposed between the conductive layer and the active surface. The conductive layer is electrically coupled to the detector housing to provide a substantially continuous conductive electrical shield surrounding the active surface. The inner surface of the detector housing is supplemented with a radio frequency absorbing material such as ferrite.
On the ground state of metallic hydrogen
Chakravarty, S.; Ashcroft, N. W.
1978-01-01
A proposed liquid ground state of metallic hydrogen at zero temperature is explored and a variational upper bound to the ground state energy is calculated. The possibility that the metallic hydrogen is a liquid around the metastable point (rs = 1.64) cannot be ruled out. This conclusion crucially hinges on the contribution to the energy arising from the third order in the electron-proton interaction which is shown here to be more significant in the liquid phase than in crystals.
A global approach to ground state solutions
Philip Korman
2008-08-01
Full Text Available We study radial solutions of semilinear Laplace equations. We try to understand all solutions of the problem, regardless of the boundary behavior. It turns out that one can study uniqueness or multiplicity properties of ground state solutions by considering curves of solutions of the corresponding Dirichlet and Neumann problems. We show that uniqueness of ground state solutions can sometimes be approached by a numerical computation.
A global approach to ground state solutions
2008-01-01
We study radial solutions of semilinear Laplace equations. We try to understand all solutions of the problem, regardless of the boundary behavior. It turns out that one can study uniqueness or multiplicity properties of ground state solutions by considering curves of solutions of the corresponding Dirichlet and Neumann problems. We show that uniqueness of ground state solutions can sometimes be approached by a numerical computation.
Tetraphenylhexaazaanthracenes: 16π Weakly Antiaromatic Species with Singlet Ground States.
Constantinides, Christos P; Zissimou, Georgia A; Berezin, Andrey A; Ioannou, Theodosia A; Manoli, Maria; Tsokkou, Demetra; Theodorou, Eleni; Hayes, Sophia C; Koutentis, Panayiotis A
2015-08-21
Tetraphenylhexaazaanthracene, TPHA-1, is a fluorescent zwitterionic biscyanine with a closed-shell singlet ground state. TPHA-1 overcomes its weak 16π antiaromaticity by partitioning its π system into 6π positive and 10π negative cyanines. The synthesis of TPHA-1 is low yielding and accompanied by two analogous TPHA isomers: the deep red, non-charge-separated, quinoidal TPHA-2, and the deep green TPHA-3 that partitions into two equal but oppositely charged 8π cyanines. The three TPHA isomers are compared.
Druzhinin, Sergey I; Galievsky, Victor A; Demeter, Attila; Kovalenko, Sergey A; Senyushkina, Tamara; Dubbaka, Srinivas R; Knochel, Paul; Mayer, Peter; Grosse, Christian; Stalke, Dietmar; Zachariasse, Klaas A
2015-12-10
From X-ray structure analysis, amino twist angles of 90.0° for 2,4-dimethyl-3-(dimethylamino)benzonitrile (mMMD), 82.7° for 4-(di-tert-butylamino)benzonitrile (DTABN), and 88.7° for 6-cyanobenzoquinuclidine (CBQ) are determined, all considerably larger than the 57.4° of 3,5-dimethyl-4-(dimethylamino)benzonitrile (MMD). This large twist leads to lengthening of the amino-phenyl bond, 143.5 pm (mMMD), 144.1 pm (DTABN), 144.6 pm (CBQ), and 141.4 pm (MMD), as compared with 136.5 pm for the planar 4-(dimethylamino)benzonitrile (DMABN). As a consequence, the electronic coupling between the amino and phenyl subgroups in mMMD, DTABN, CBQ, and MMD is much weaker than in DMABN, as seen from the strongly reduced molar absorption coefficients. The fluorescence spectrum of MMD in n-hexane at 25 °C consists of two emissions, from a locally excited (LE) and an intramolecular charge transfer (ICT) state, with a fluorescence quantum yield ratio Φ'(ICT)/Φ(LE) of 12.8. In MeCN, a single ICT emission is found. With mMMD in n-hexane, in contrast, only LE fluorescence is observed, whereas the spectrum in MeCN originates from the ICT state. These differences are also seen from the half-widths of the overall fluorescence bands, which in n-hexane are larger for MMD than for mMMD, decreasing with solvent polarity for MMD and increasing for mMMD, reflecting the disappearance of LE and the onset of ICT in the overall spectra, respectively. From solvatochromic measurements the dipole moments μe(ICT) of MMD (16 D) and mMMD (15 D) are obtained. Femtosecond excited state absorption (ESA) spectra at 22 °C, together with the dual (LE + ICT) fluorescence, reveal that MMD in n-hexane undergoes a reversible LE ⇄ ICT reaction, with LE as the precursor, with a forward rate constant ka = 5.6 × 10(12) s(-1) and a back-reaction kd ∼ 0.05 × 10(12) s(-1). With MMD in the strongly polar solvent MeCN, ICT is faster: ka = 10 × 10(12) s(-1). In the case of mMMD in n-hexane, the ESA spectra show
Vacuum polarization screening corrections to the ground state energy of two-electron ions
Artemiev, A N; Yerokhin, V A
1997-01-01
Vacuum polarization screening corrections to the ground state energy of two-electron ions are calculated in the range $Z=20-100$. The calculations are carried out for a finite nucleus charge distribution.
Reynisson, J.; Wilbrandt, R.; Brinck, V.
2002-01-01
of the long wavelength absorption band. A strong fluorescence is observed at 520 nm (tau(n) = 14.6 ns, phi(n) = 0.12 in deaerated acetonitrile). The fluorescence is quenched by 10 aromatic electron donors predominantly via a dynamic charge transfer mechanism, but ground state complexation is shown...
Ground states for nonuniform periodic Ising chains
Martínez-Garcilazo, J. P.; Ramírez, C.
2015-04-01
We generalize Morita's works [J. Phys. A 7, 289 (1974), 10.1088/0305-4470/7/2/014; J. Phys. A 7, 1613 (1974), 10.1088/0305-4470/7/13/015] on ground states of Ising chains, for chains with a periodic structure and different spins, to any interaction order. The main assumption is translational invariance. The length of the irreducible blocks is a multiple of the period of the chain. If there is parity invariance, it restricts the length in general only in the diatomic case. There are degenerated states and under certain circumstances there could be nonregular ground states. We illustrate the results and give the ground state diagrams in several cases.
Fractional charge and spin states in topological insulator constrictions
Klinovaja, Jelena; Loss, Daniel
2015-09-01
We theoretically investigate the properties of two-dimensional topological insulator constrictions both in the integer and fractional regimes. In the presence of a perpendicular magnetic field, the constriction functions as a spin filter with near-perfect efficiency and can be switched by electric fields only. Domain walls between different topological phases can be created in the constriction as an interface between tunneling, magnetic fields, charge density wave, or electron-electron interaction dominated regions. These domain walls host non-Abelian bound states with fractional charge and spin and result in degenerate ground states with parafermions. If a proximity gap is induced bound states give rise to an exotic Josephson current with 8 π periodicity.
Quantum collision states for positive charges in an octahedral cage
Mendes, R V
2003-01-01
One-electron energy levels are studied for a configuration of two positive charges inside an octahedral cage, the vertices of the cage being occupied by atoms with a partially filled shell. Although ground states correspond to large separations, there are relatively low-lying states with large collision probabilities. Electromagnetic radiation fields used to excite the quantum collisional levels may provide a means to control nuclear reactions. However, given the scale of the excitation energies involved, this mechanism cannot provide an explanation for the unexplained ``cold fusion'' events.
Ground states of linearly coupled Schrodinger systems
Haidong Liu
2017-01-01
Full Text Available This article concerns the standing waves of a linearly coupled Schrodinger system which arises from nonlinear optics and condensed matter physics. The coefficients of the system are spatially dependent and have a mixed behavior: they are periodic in some directions and tend to positive constants in other directions. Under suitable assumptions, we prove that the system has a positive ground state. In addition, when the L-infinity-norm of the coupling coefficient tends to zero, the asymptotic behavior of the ground states is also obtained.
Trapped Antihydrogen in Its Ground State
Gabrielse, G; Kolthammer, W S; McConnell, R; Richerme, P; Grzonka, D; Oelert, W; Sefzick, T; Zielinski, M; Fitzakerley, D W; George, M C; Hessels, E A; Storry, C H; Weel, M; Mullers, A; Walz, J
2012-01-01
Antihydrogen atoms are confined in an Ioffe trap for 15 to 1000 seconds -- long enough to ensure that they reach their ground state. Though reproducibility challenges remain in making large numbers of cold antiprotons and positrons interact, 5 +/- 1 simultaneously-confined ground state atoms are produced and observed on average, substantially more than previously reported. Increases in the number of simultaneously trapped antithydrogen atoms H are critical if laser-cooling of trapped antihydrogen is to be demonstrated, and spectroscopic studies at interesting levels of precision are to be carried out.
Environment-protected solid-state-based distributed charge qubit
Tayebi, Amin; Hoatson, Tanya Nicole; Wang, Joie; Zelevinsky, Vladimir
2016-12-01
A solid-state-based charge qubit is presented. The system consists of a one-dimensional wire with a pair of qubits embedded at its center. It is shown that the system supports collective states localized in the left and right sides of the wire and therefore, as a whole, performs as a single qubit. The couplings between the ground and excited states of the two central qubits are inversely proportional making them fully asynchronized and allowing for coherent manipulation and gate operations. Initialization and measurement devices, such as leads and charge detectors, connected to the edges of the wire are modeled by a continuum of energy states. The coupling to the continuum is discussed using the effective non-Hermitian Hamiltonian. At weak continuum coupling, all internal states uniformly acquire small decay widths. This changes dramatically as the coupling strength increases: the width distribution undergoes a sharp restructuring and is no longer uniformly divided among the eigenstates. Two broad resonances localized at the ends of the wire are formed. These superradiant states (analogous to Dicke states in quantum optics) effectively protect the remaining internal states from decaying into the continuum and hence increase the lifetime of the qubit. Environmental noise is introduced by considering random Gaussian fluctuations of electronic energies. The interplay between decoherence and superradiance is studied by solving the stochastic Liouville equation. In addition to increasing the lifetime, the emergence of the superradiant states increases the qubit coherence.
Ground state of a confined Yukawa plasma
Henning, C; Block, D; Bonitz, M; Golubnichiy, V; Ludwig, P; Piel, A
2006-01-01
The ground state of an externally confined one-component Yukawa plasma is derived analytically. In particular, the radial density profile is computed. The results agree very well with computer simulations on three-dimensional spherical Coulomb crystals. We conclude in presenting an exact equation for the density distribution for a confinement potential of arbitrary geometry.
Rearrangements in ground and excited states
de Mayo, Paul
1980-01-01
Rearrangements in Ground and Excited States, Volume 3 presents essays on the chemical generation of excited states; the cis-trans isomerization of olefins; and the photochemical rearrangements in trienes. The book also includes essays on the zimmerman rearrangements; the photochemical rearrangements of enones; the photochemical rearrangements of conjugated cyclic dienones; and the rearrangements of the benzene ring. Essays on the photo rearrangements via biradicals of simple carbonyl compounds; the photochemical rearrangements involving three-membered rings or five-membered ring heterocycles;
Theoretical study of the ground state of (EDO-TTF)(2)PF6
Linker, Gerrit-Jan; van Duijnen, Piet Th.; van Loosdrecht, Paul H.M.; Broer, Ria
2015-01-01
In this paper we present a theoretical study of the nature of the ground state of the (EDO-TTF)(2)PF6 charge transfer salt by using ab initio quantum chemical theory for clusters in vacuum, for embedded clusters and for the periodic system. Exemplary for other organic charge transfer systems, we sho
Trapping cold ground state argon atoms.
Edmunds, P D; Barker, P F
2014-10-31
We trap cold, ground state argon atoms in a deep optical dipole trap produced by a buildup cavity. The atoms, which are a general source for the sympathetic cooling of molecules, are loaded in the trap by quenching them from a cloud of laser-cooled metastable argon atoms. Although the ground state atoms cannot be directly probed, we detect them by observing the collisional loss of cotrapped metastable argon atoms and determine an elastic cross section. Using a type of parametric loss spectroscopy we also determine the polarizability of the metastable 4s[3/2](2) state to be (7.3±1.1)×10(-39) C m(2)/V. Finally, Penning and associative losses of metastable atoms in the absence of light assisted collisions, are determined to be (3.3±0.8)×10(-10) cm(3) s(-1).
Numerical calculation of impurity charge state distributions
Crume, E. C.; Arnurius, D. E.
1977-09-01
The numerical calculation of impurity charge state distributions using the computer program IMPDYN is discussed. The time-dependent corona atomic physics model used in the calculations is reviewed, and general and specific treatments of electron impact ionization and recombination are referenced. The complete program and two examples relating to tokamak plasmas are given on a microfiche so that a user may verify that his version of the program is working properly. In the discussion of the examples, the corona steady-state approximation is shown to have significant defects when the plasma environment, particularly the electron temperature, is changing rapidly.
Electronic Ground State of Higher Acenes
Jiang, De-en
2007-01-01
We examine the electronic ground state of acenes with different number of fused benzene rings (up to 40) by using first principles density functional theory. Their properties are compared with those of infinite polyacene. We find that the ground state of acenes that consist of more than seven fused benzene rings is an antiferromagnetic (in other words, open-shell singlet) state, and we show that this singlet is not necessarily a diradical, because the spatially separated magnetizations for the spin-up and spin-down electrons increase with the size of the acene. For example, our results indicate that there are about four spin-up electrons localized at one zigzag edge of 20-acene. The reason that both acenes and polyacene have the antiferromagnetic ground state is due to the zigzag-shaped boundaries, which cause pi-electrons to localize and form spin orders at the edges. Both wider graphene ribbons and large rectangular-shaped polycyclic aromatic hydrocarbons have been shown to share this antiferromagnetic grou...
Ground- and excited-state impurity bands in quantum wells
Ghazali, A.; Gold, A.; Serre, J.
1989-02-01
The density of states and the spectral density of electrons in quantum wells with charged impurities are calculated with use of a multiple-scattering method. The impurity-density-dependent broadening and the gradual merging of the ground (1s) and excited (2p+/-,2s) impurity levels into impurity bands are investigated. At low density the shapes of the 1s, 2p+/-, and 2s spectral densities are found to be in excellent agreement with the analytical results obtained for the ideal two-dimensional Coulomb problem.
Magnetic properties of ground-state mesons
Simonis, V. [Vilnius University Institute of Theoretical Physics and Astronomy, Vilnius (Lithuania)
2016-04-15
Starting with the bag model a method for the study of the magnetic properties (magnetic moments, magnetic dipole transition widths) of ground-state mesons is developed. We calculate the M1 transition moments and use them subsequently to estimate the corresponding decay widths. These are compared with experimental data, where available, and with the results obtained in other approaches. Finally, we give the predictions for the static magnetic moments of all ground-state vector mesons including those containing heavy quarks. We have a good agreement with experimental data for the M1 decay rates of light as well as heavy mesons. Therefore, we expect our predictions for the static magnetic properties (i.e., usual magnetic moments) to be of sufficiently high quality, too. (orig.)
First observation of $^{13}$Li ground state
Kohley, Z; DeYoung, P A; Volya, A; Baumann, T; Bazin, D; Christian, G; Cooper, N L; Frank, N; Gade, A; Hall, C; Hinnefeld, J; Luther, B; Mosby, S; Peters, W A; Smith, J K; Snyder, J; Spyrou, A; Thoennessen, M
2013-01-01
The ground state of neutron-rich unbound $^{13}$Li was observed for the first time in a one-proton removal reaction from $^{14}$Be at a beam energy of 53.6 MeV/u. The $^{13}$Li ground state was reconstructed from $^{11}$Li and two neutrons giving a resonance energy of 120$^{+60}_{-80}$ keV. All events involving single and double neutron interactions in the Modular Neutron Array (MoNA) were analyzed, simulated, and fitted self-consistently. The three-body ($^{11}$Li+$n+n$) correlations within Jacobi coordinates showed strong dineutron characteristics. The decay energy spectrum of the intermediate $^{12}$Li system ($^{11}$Li+$n$) was described with an s-wave scattering length of greater than -4 fm, which is a smaller absolute value than reported in a previous measurement.
Magnetic properties of ground-state mesons
Simonis, Vytautas
2016-01-01
Starting with the bag model a method for the study of the magnetic properties (magnetic moments, magnetic dipole transition widths) of ground-state mesons is developed. We calculate the M1 transition moments and use them subsequently to estimate the corresponding decay widths. These are compared with experimental data, where available, and with the results obtained in other approaches. Finally, we give the predictions for the static magnetic moments of all ground-state vector mesons including those containing heavy quarks. We have a good agreement with experimental data for the M1 decay rates of light as well as heavy mesons. Therefore, we expect our predictions for the static magnetic properties (usual magnetic moments) to be of sufficiently high quality, too.
Electronic ground state of Ni$_2^+$
Zamudio-Bayer, V; Bülow, C; Leistner, G; Terasaki, A; Issendorff, B v; Lau, J T
2016-01-01
The $^{4}\\Phi_{9/2}$ ground state of the Ni$_2^+$ diatomic molecular cation is determined experimentally from temperature and magnetic-field-dependent x-ray magnetic circular dichroism spectroscopy in a cryogenic ion trap, where an electronic and rotational temperature of $7.4 \\pm 0.2$ K was achieved by buffer gas cooling of the molecular ion. The contribution of the magnetic dipole term to the x-ray magnetic circular dichroism spin sum rule amounts to $7\\, T_z = 0.17 \\pm 0.06$ $\\mu_B$ per atom, approximately 11 \\% of the spin magnetic moment. We find that, in general, homonuclear diatomic molecular cations of $3d$ transition metals seem to adopt maximum spin magnetic moments in their electronic ground states.
Strangeness in the baryon ground states
Semke, A
2012-01-01
We compute the strangeness content of the baryon ground states based on an analysis of recent lattice simulations of the BMW, PACS, LHPC and HSC groups for the pion-mass dependence of the baryon masses. Our results rely on the relativistic chiral Lagrangian and large-$N_c$ sum rule estimates of the counter terms relevant for the baryon masses at N$^3$LO. A partial summation is implied by the use of physical baryon and meson masses in the one-loop contributions to the baryon self energies. A simultaneous description of the lattice results of the BMW, LHPC, PACS and HSC groups is achieved. We predict the pion- and strangeness sigma terms and the pion-mass dependence of the octet and decuplet ground states at different strange quark masses.
Rearrangements in ground and excited states
de Mayo, Paul
1980-01-01
Rearrangements in Ground and Excited States, Volume 2 covers essays on the theoretical approach of rearrangements; the rearrangements involving boron; and the molecular rearrangements of organosilicon compounds. The book also includes essays on the polytopal rearrangement at phosphorus; the rearrangement in coordination complexes; and the reversible thermal intramolecular rearrangements of metal carbonyls. Chemists and people involved in the study of rearrangements will find the book invaluable.
Ground states for the fractional Schrodinger equation
Binhua Feng
2013-05-01
Full Text Available In this article, we show the existence of ground state solutions for the nonlinear Schrodinger equation with fractional Laplacian $$ (-Delta ^alpha u+ V(xu =lambda |u|^{p}uquadhbox{in $mathbb{R}^N$ for $alpha in (0,1$}. $$ We use the concentration compactness principle in fractional Sobolev spaces $H^alpha$ for $alpha in (0,1$. Our results generalize the corresponding results in the case $alpha =1$.
The polaron: Ground state, excited states, and far from equilibrium
Trugman, S.A. [Los Alamos National Lab., NM (United States). Theory Div.; Bonca, J. [Univ. of Ljubljana (Slovenia)]|[Jozef Stefan Inst., Ljubljana (Slovenia)
1998-12-01
The authors describe a variational approach for solving the Holstein polaron model with dynamical quantum phonons on an infinite lattice. The method is simple, fast, extremely accurate, and gives ground and excited state energies and wavefunctions at any momentum k. The method can also be used to calculate coherent quantum dynamics for inelastic tunneling and for strongly driven polarons far from equilibrium.
Superimposed particles in 1D ground states
Sueto, Andras, E-mail: suto@szfki.hu [Research Institute for Solid State Physics and Optics, Hungarian Academy of Sciences, PO Box 49, H-1525 Budapest (Hungary)
2011-01-21
For a class of nonnegative, range-1 pair potentials in one-dimensional continuous space we prove that any classical ground state of lower density {>=}1 is a tower-lattice, i.e. a lattice formed by towers of particles the heights of which can differ only by 1, and the lattice constant is 1. The potential may be flat or may have a cusp at the origin; it can be continuous, but its derivative has a jump at 1. The result is valid on finite intervals or rings of integer length and on the whole line.
Hyperfine splitting of the dressed hydrogen atom ground state in non-relativistic QED
Amour, L
2010-01-01
We consider a spin-1/2 electron and a spin-1/2 nucleus interacting with the quantized electromagnetic field in the standard model of non-relativistic QED. For a fixed total momentum sufficiently small, we study the multiplicity of the ground state of the reduced Hamiltonian. We prove that the coupling between the spins of the charged particles and the electromagnetic field splits the degeneracy of the ground state.
New ground state for quantum gravity
Magueijo, Joao
2012-01-01
In this paper we conjecture the existence of a new "ground" state in quantum gravity, supplying a wave function for the inflationary Universe. We present its explicit perturbative expression in the connection representation, exhibiting the associated inner product. The state is chiral, dependent on the Immirzi parameter, and is the vacuum of a second quantized theory of graviton particles. We identify the physical and unphysical Hilbert sub-spaces. We then contrast this state with the perturbed Kodama state and explain why the latter can never describe gravitons in a de Sitter background. Instead, it describes self-dual excitations, which are composites of the positive frequencies of the right-handed graviton and the negative frequencies of the left-handed graviton. These excitations are shown to be unphysical under the inner product we have identified. Our rejection of the Kodama state has a moral tale to it: the semi-classical limit of quantum gravity can be the wrong path for making contact with reality (w...
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2012-10-01
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Liu, Junzi; Zhang, Yong; Bao, Peng; Yi, Yuanping
2017-02-14
Electronic couplings of charge-transfer states with the ground state and localized excited states at the donor/acceptor interface are crucial parameters for controlling the dynamics of exciton dissociation and charge recombination processes in organic solar cells. Here we propose a quasi-adiabatic state approach to evaluate electronic couplings through combining maximum occupation method (mom)-ΔSCF and state diabatization schemes. Compared with time-dependent density functional theory (TDDFT) using global hybrid functional, mom-ΔSCF is superior to estimate the excitation energies of charge-transfer states; moreover it can also provide good excited electronic state for property calculation. Our approach is hence reliable to evaluate electronic couplings for excited state electron transfer processes, which is demonstrated by calculations on a typical organic photovoltaic system, oligothiophene/perylenediimide complex.
Spatial competition of the ground states in 1111 iron pnictides
Lang, G.; Veyrat, L.; Gräfe, U.; Hammerath, F.; Paar, D.; Behr, G.; Wurmehl, S.; Grafe, H.-J.
2016-07-01
Using nuclear quadrupole resonance, the phase diagram of 1111 R FeAsO1 -xFx (R =La , Ce, Sm) iron pnictides is constructed as a function of the local charge distribution in the paramagnetic state, which features low-doping-like (LD-like) and high-doping-like (HD-like) regions. Compounds based on magnetic rare earths (Ce, Sm) display a unified behavior, and comparison with La-based compounds reveals the detrimental role of static iron 3 d magnetism on superconductivity, as well as a qualitatively different evolution of the latter at high doping. It is found that the LD-like regions fully account for the orthorhombicity of the system, and are thus the origin of any static iron magnetism. Orthorhombicity and static magnetism are not hindered by superconductivity but limited by dilution effects, in agreement with two-dimensional (2D) (respectively three-dimensional) nearest-neighbor square lattice site percolation when the rare earth is nonmagnetic (respectively magnetic). The LD-like regions are not intrinsically supportive of superconductivity, contrary to the HD-like regions, as evidenced by the well-defined Uemura relation between the superconducting transition temperature and the superfluid density when accounting for the proximity effect. This leads us to propose a complete description of the interplay of ground states in 1111 pnictides, where nanoscopic regions compete to establish the ground state through suppression of superconductivity by static magnetism, and extension of superconductivity by proximity effect.
Ground state of high-density matter
Copeland, ED; Kolb, Edward W.; Lee, Kimyeong
1988-01-01
It is shown that if an upper bound to the false vacuum energy of the electroweak Higgs potential is satisfied, the true ground state of high-density matter is not nuclear matter, or even strange-quark matter, but rather a non-topological soliton where the electroweak symmetry is exact and the fermions are massless. This possibility is examined in the standard SU(3) sub C tensor product SU(2) sub L tensor product U(1) sub Y model. The bound to the false vacuum energy is satisfied only for a narrow range of the Higgs boson masses in the minimal electroweak model (within about 10 eV of its minimum allowed value of 6.6 GeV) and a somewhat wider range for electroweak models with a non-minimal Higgs sector.
Ground State Properties of Neutron Magic Nuclei
Saxena, G
2016-01-01
A systematic study of the ground state properties of the entire chains of even even neutron magic nuclei represented by isotones of traditional neutron magic numbers N = 8, 20, 40, 50, 82 and 126 has been carried out using relativistic mean field (rmf) plus Bardeen Cooper Schrieffer (BCS) approach. Our present investigation includes deformation, binding energy, two proton separation energy, single particle energy, rms radii along with proton and neutron density profiles, etc. Several of these results are compared with the results calculated using non relativistic approach (Skyrme Hartree Fock method) along with available experimental data and indeed they are found with excellent agreement. In addition, the possible locations of the proton and neutron drip lines, the (Z,N) values for the new shell closures, disappearance of traditional shell closures as suggested by the detailed analyzes of results are also discussed in detail.
Thermodynamic ground states of platinum metal nitrides
Aberg, D; Sadigh, B; Crowhurst, J; Goncharov, A
2007-10-09
We have systematically studied the thermodynamic stabilities of various phases of the nitrides of the platinum metal elements using density functional theory. We show that for the nitrides of Rh, Pd, Ir and Pt two new crystal structures, in which the metal ions occupy simple tetragonal lattice sites, have lower formation enthalpies at ambient conditions than any previously proposed structures. The region of stability can extend up to 17 GPa for PtN{sub 2}. Furthermore, we show that according to calculations using the local density approximation, these new compounds are also thermodynamically stable at ambient pressure and thus may be the ground state phases for these materials. We further discuss the fact that the local density and generalized gradient approximations predict different values of the absolute formation enthalpies as well different relative stabilities between simple tetragonal and the pyrite or marcasite structures.
Ground state correlations and mean-field in $^{16}O$, 2
Mihaila, B; Mihaila, Bogdan; Heisenberg, Jochen H.
2000-01-01
We continue the investigations of the $^{16}$O ground state using the coupled-cluster expansion [$\\exp({\\bf S})$] method with realistic nuclear interaction. In this stage of the project, we take into account the three nucleon interaction, and examine in some detail the definition of the internal Hamiltonian, thus trying to correct for the center-of-mass motion. We show that this may result in a better separation of the internal and center-of-mass degrees of freedom in the many-body nuclear wave function. The resulting ground state wave function is used to calculate the "theoretical" charge form factor and charge density. Using the "theoretical" charge density, we generate the charge form factor in the DWBA picture, which is then compared with the available experimental data. The longitudinal response function in inclusive electron scattering for $^{16}$O is also computed.
Screened test-charge - test-charge interaction in the two-dimensional electron gas: bound states
Gold, A.; Ghazali, A.
1997-08-01
We study the test-charge - test-charge interaction when screening effects of a two-dimensional electron gas are taken into account. The Schrödinger equation is solved in the momentum space by diagonalizing the corresponding matrix and the results are compared with variational calculations. For two positive (or negative) test-charges bound states are obtained for low electron densities when many-body effects are incorporated in the screening function. For a density larger than a critical density, 0953-8984/9/32/011/img5 (0953-8984/9/32/011/img6 is the Wigner - Seitz parameter), no bound states are found. Below the critical density, 0953-8984/9/32/011/img7, the number of bound states and their energy increase with decreasing density and the ground-state binding energy saturates near 0953-8984/9/32/011/img8. Finite-width effects for quantum wells are also discussed. We present new results for bound states between a positive and a negative test charge and we discuss effects of exchange and correlation on the binding energies.
Electroluminescence from charge transfer states in Donor/Acceptor solar cells
Sherafatipour, Golenaz; Madsen, Morten
charge transfer (CT) excitons, which is Coulombically bound interfacial electron- hole pairs residing at the donor/acceptor heterojunctions. The CT state represents an intermediate state between the exciton dissociation and recombination back to the ground state. Since the recombination of photo...... at the donor/acceptor interface is detected. As a less studied system, we examine here the interfacial charge transfer state recombination in DBP:C70 thin-films. The weak EL from the small molecule solar cell biased in the forward direction gives valuable information about the CT state recombination, from...... which the maximum open-circuit voltage can be estimated, and further can be used in the modeling and optimization of the OPV devices. [1] C. Deibe, T. Strobe, and V. Dyakonov, “Role of the charge transfer state in organic donor-acceptor solar cells,” Adv. Mater., vol. 22, pp. 4097–4111, 2010. [2] K...
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2013-10-03
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Quantum dynamics of charge state in silicon field evaporation
Elena P. Silaeva
2016-08-01
Full Text Available The charge state of an ion field-evaporating from a silicon-atom cluster is analyzed using time-dependent density functional theory coupled to molecular dynamics. The final charge state of the ion is shown to increase gradually with increasing external electrostatic field in agreement with the average charge state of silicon ions detected experimentally. When field evaporation is triggered by laser-induced electronic excitations the charge state also increases with increasing intensity of the laser pulse. At the evaporation threshold, the charge state of the evaporating ion does not depend on the electrostatic field due to the strong contribution of laser excitations to the ionization process both at low and high laser energies. A neutral silicon atom escaping the cluster due to its high initial kinetic energy is shown to be eventually ionized by external electrostatic field.
ZHANG Yijun; MENG Qing; LU Weitao; Paul Krehbiel; LIU Xinsheng; ZhOU Xiuji
2006-01-01
The charge structures and temporal and spatial characteristics of cloud-to-ground (CG) lightning discharges in two supercell thunderstorms have been analyzed based on the data of three-dimen- sional VHF radiation sources with high time and space resolution produced by lightning discharges. The results indicate that the charge structures in main part (convective region) of the thunderstorms were inverted tripole while a number of positive CG lightning discharges were occurring in the two thunderstorms. The positive CG lightning discharges occurred in main part of the thunderstorms and originated from the positive charge region located at the middle part of the thunderstorms. While a number of negative CG lightning discharges were occurring, the negative CG lightning discharges occurred in the anvil of the thunderstorm. The charge structure is inverted dipole in the region due to the slant of charge structure in main region toward anvil region. The negative charge region located at the upper part of anvil produced a lot of negative CG lightning discharges. No or less CG lighting was produced directly by the charge region located at the lower part of the thunderstorm. The charge region in lower part of the thunderstorm plays an important role for the occurrence of CG lightning from charge region above it.
Charge-displacement analysis for excited states
Ronca, Enrico, E-mail: enrico@thch.unipg.it; Tarantelli, Francesco, E-mail: francesco.tarantelli@unipg.it [Istituto CNR di Scienze e Tecnologie Molecolari, via Elce di Sotto 8, I-06123 Perugia (Italy); Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, via Elce di Sotto 8, I-06123 Perugia (Italy); Pastore, Mariachiara, E-mail: chiara@thch.unipg.it; Belpassi, Leonardo; De Angelis, Filippo [Istituto CNR di Scienze e Tecnologie Molecolari, via Elce di Sotto 8, I-06123 Perugia (Italy); Angeli, Celestino; Cimiraglia, Renzo [Dipartimento di Scienze Chimiche e Farmaceutiche, Università degli Studi di Ferrara, via Borsari 46, I-44100 Ferrara (Italy)
2014-02-07
We extend the Charge-Displacement (CD) analysis, already successfully employed to describe the nature of intermolecular interactions [L. Belpassi et al., J. Am. Chem. Soc. 132, 13046 (2010)] and various types of controversial chemical bonds [L. Belpassi et al., J. Am. Chem. Soc. 130, 1048 (2008); N. Salvi et al., Chem. Eur. J. 16, 7231 (2010)], to study the charge fluxes accompanying electron excitations, and in particular the all-important charge-transfer (CT) phenomena. We demonstrate the usefulness of the new approach through applications to exemplary excitations in a series of molecules, encompassing various typical situations from valence, to Rydberg, to CT excitations. The CD functions defined along various spatial directions provide a detailed and insightful quantitative picture of the electron displacements taking place.
Charge sensitive amplifies. The state of arts
Mori, Kunishiro [Clear Pulse Co., Tokyo (Japan)
1996-07-01
In the radiation detectors, signals are essentially brought with charges produced by radiation, then it is naturally the best way to use a charge sensitive amplifier (CSA) system to extract those signals. The CSA is thought to be the best amplifier suitable to almost all the radiation detectors, if neglecting economical points of view. The CSA has been only applied to special fields like radiation detection because the concept of `charges` is not so universal against the concepts of `voltage` and `current`. The CSA, however, is low in noise and a high speed amplifier and may be applicable not only to radiation measurement but also piezoelectric devices and also bolometers. In this article, noise in the CSA, basic circuit on the CSA, concepts of `equivalent noise charge` (ENC), a method for the ENC, and importance of the `open-loop gain` in the CSA to achieve better performance of it and how to realize in a practical CSA were described. And, characteristics on a counting rate of the CSA, various circuit used in the CSA, and CSAs which are commercially available at present and special purpose CSAs were also introduced. (G.K.)
The ECRIS charge state breeding project at TRIUMF.
Ames, F; Baartman, R; Bricault, P; Jayamanna, K; McDonald, M; Schmor, P; Spanjers, T; Yuan, D H L; Lamy, T
2008-02-01
The performance of charge state breeding with an electron cyclotron resonance (ECR) ion source intended to increase the charge state of online produced radioactive ions at the ISAC facility at TRIUMF has been investigated. A 14 GHz PHOENIX from PANTECHNIK has been setup on a test bench. Singly charged ions have been produced with several ion sources typical for the on-line operation and were injected into the charge breeder. The main purpose of the tests has been the optimization of the efficiency for the charge breeding into the desired charge state. Maximum efficiencies reached so far with the standard one step deceleration of the ions in front of the plasma are up to about 6% for noble gas ions and about 3.5% for alkalines. As ion optics simulations show, the acceptance can be increased by a two step deceleration. In order to meet the velocity acceptance of the accelerator at different A/q values a similar two gap acceleration system for the highly charged ions has been installed to allow the source to run at different voltages. For the further beam transport to the accelerator, cross sections for charge exchange of the highly charged ions with the residual gas have been determined.
The axial charges of the hidden-charm pentaquark states
Wang, Guang-Juan; Zhu, Shi-Lin
2016-01-01
With the chiral quark model, we have calculated the axial charges of the pentaquark states with $(I,I_3)=(\\frac{1}{2},\\frac{1}{2})$ and $J^{P}=\\frac{1}{2}^{\\pm},\\frac{3}{2}^{\\pm},\\frac{5}{2}^{\\pm}$. The $P_c$ states with the same $J^P$ quantum numbers but different color-spin-flavor configurations have very different axial charges, which encode important information on their underlying structures. For some of the $J^{P}=\\frac{3}{2}^{\\pm}$ or $\\frac{5}{2}^{\\pm}$ pentaquark states, their axial charges are much smaller than that of the proton.
Solving Quantum Ground-State Problems with Nuclear Magnetic Resonance
Li, Zhaokai; Chen, Hongwei; Lu, Dawei; Whitfield, James D; Peng, Xinhua; Aspuru-Guzik, Alán; Du, Jiangfeng
2011-01-01
Quantum ground-state problems are computationally hard problems; for general many-body Hamiltonians, there is no classical or quantum algorithm known to be able to solve them efficiently. Nevertheless, if a trial wavefunction approximating the ground state is available, as often happens for many problems in physics and chemistry, a quantum computer could employ this trial wavefunction to project the ground state by means of the phase estimation algorithm (PEA). We performed an experimental realization of this idea by implementing a variational-wavefunction approach to solve the ground-state problem of the Heisenberg spin model with an NMR quantum simulator. Our iterative phase estimation procedure yields a high accuracy for the eigenenergies (to the 10^-5 decimal digit). The ground-state fidelity was distilled to be more than 80%, and the singlet-to-triplet switching near the critical field is reliably captured. This result shows that quantum simulators can better leverage classical trial wavefunctions than c...
Highly charged ions in Penning traps, a new tool for resolving low lying isomeric states
Gallant, A T; Brunner, T; Chowdhury, U; Ettenauer, S; Simon, V V; Mané, E; Simon, M C; Andreoiu, C; Delheij, P; Gwinner, G; Pearson, M R; Ringle, R; Dilling, J
2011-01-01
The use of highly charged ions greatly increases the precision and resolving power, in particular for short-lived species produced at on-line radio-isotope beam facilities, achievable with Penning trap mass spectrometers. This increase in resolving power provides a new and unique access to resolving low-lying long-lived ($T_{1/2} > 50$ ms) nuclear isomers. Recently, the $111.19(22)$ keV (determined from $\\gamma$-ray spectroscopy) isomeric state in $^{78}$Rb has been resolved from the ground state, in a charge state of $q=8+$ with the TITAN Penning trap at the TRIUMF-ISAC facility. The energy level of the isomer was measured to be $108.7(6.4)$ keV above the ground state. The extracted masses for both the ground and isomeric states, and their difference, agree with the AME2003 and Nuclear Data Sheet values. This proof of principle measurement demonstrates the feasibility of using Penning trap mass spectrometers coupled to charge breeders to study nuclear isomers and opens a new route for isomer searches.
E.Javadimanesh; H.Hassanabadi; A.A.Rajabi; H.Rahimov; S.Zarrinkamar
2012-01-01
We study the half-lives of some nuclei via the alpha-decay process from ground state to ground state. To go through the problem, we have considered a potential model with Yukawa proximity potential and have thereby calculated the half-lives. The comparison with the existing data is motivating.
Measurements of aerosol charging states in Helsinki, Finland
S. Gagné
2011-05-01
Full Text Available The charging state of aerosol populations was measured with an Ion-DMPS in Helsinki, Finland between December 2008 and February 2010. Based on the charging states, we calculated the ion-induced nucleation fraction to be around 0.8 % ± 0.9 %. We review the role of ion-induced nucleation and propose different explanations for a low ion-induced nucleation participation in urban areas. We present a new method to retrieve the average charging state for an event, and a given size. We also use a new theoretical framework that allows for different concentrations of small cluster ions for different polarities (polarity asymmetry. We extrapolate the ion-induced fraction using polarity symmetry and asymmetry. Finally, a method to calculate the growth rates from the variation of the charging state as a function of the particle diameter using polarity symmetry and asymmetry is presented and used on a selection of new particle formation events.
Explosion and final state of the charged black hole bomb
Sanchis-Gual, Nicolas; Montero, Pedro J; Font, José A; Herdeiro, Carlos
2015-01-01
A Reissner-Nordstr\\"om black hole (BH) is superradiantly unstable against spherical perturbations of a charged scalar field, enclosed in a cavity, with frequency lower than a critical value. We use numerical relativity techniques to follow the development of this unstable system -- dubbed charged BH bomb -- into the non-linear regime, solving the full Einstein--Maxwell--Klein-Gordon equations, in spherical symmetry. We show that: $i)$ the process stops before all the charge is extracted from the BH; $ii)$ the system settles down into a hairy BH: a charged horizon in equilibrium with a scalar field condensate, whose phase is oscillating at the (final) critical frequency. For low scalar field charge, $q$, the final state is approached smoothly and monotonically. For large $q$, however, the energy extraction overshoots and an explosive phenomenon, akin to a $bosenova$, pushes some energy back into the BH. The charge extraction, by contrast, does not reverse.
Quantum State Transmission in a Superconducting Charge Qubit-Atom Hybrid.
Yu, Deshui; Valado, María Martínez; Hufnagel, Christoph; Kwek, Leong Chuan; Amico, Luigi; Dumke, Rainer
2016-12-06
Hybrids consisting of macroscopic superconducting circuits and microscopic components, such as atoms and spins, have the potential of transmitting an arbitrary state between different quantum species, leading to the prospective of high-speed operation and long-time storage of quantum information. Here we propose a novel hybrid structure, where a neutral-atom qubit directly interfaces with a superconducting charge qubit, to implement the qubit-state transmission. The highly-excited Rydberg atom located inside the gate capacitor strongly affects the behavior of Cooper pairs in the box while the atom in the ground state hardly interferes with the superconducting device. In addition, the DC Stark shift of the atomic states significantly depends on the charge-qubit states. By means of the standard spectroscopic techniques and sweeping the gate voltage bias, we show how to transfer an arbitrary quantum state from the superconducting device to the atom and vice versa.
Quantum State Transmission in a Superconducting Charge Qubit-Atom Hybrid
Yu, Deshui; Hufnagel, Christoph; Kwek, Leong Chuan; Amico, Luigi; Dumke, Rainer
2016-01-01
Hybrids consisting of macroscopic superconducting circuits and microscopic components, such as atoms and spins, have the potential of transmitting an arbitrary state between different quantum species, leading to the prospective of high-speed operation and long-time storage of quantum information. Here we propose a novel hybrid structure, where a neutral-atom qubit directly interfaces with a superconducting charge qubit, to implement the qubit-state transmission. The highly-excited Rydberg atom located inside the gate capacitor strongly affects the behavior of Cooper pairs in the box while the atom in the ground state hardly interferes with the superconducting device. In addition, the DC Stark shift of the atomic states significantly depends on the charge-qubit states. By means of the standard spectroscopic techniques and sweeping the gate voltage bias, we show how to transfer an arbitrary quantum state from the superconducting device to the atom and vice versa.
Vogel, Stephan; Lopez, Javier; Holbøll, Joachim;
2015-01-01
that the effectof the removal of the corona space charge by the wind leadsto a higher field strength at the grounded object and, therefore,it becomes easier for it to initiate an upward connecting leadercompared to a situation where the space charge is present. Inthis work, a simplified space charge drift model...
Hardware and software for ground tests of onboard charged particle spectrometers
Batischev, A. G., E-mail: Alexey-Batischev@mail.ru; Galper, A. M. [National Research Nuclear University MEPhI (Moscow Engineering Physics Institute) (Russian Federation); Grishin, S. A. [Academy of Sciences of Belarus, Stepanov Institute of Physics, National (Belarus); Naumov, P. Yu. [National Research Nuclear University MEPhI (Moscow Engineering Physics Institute) (Russian Federation); Niadvetski, N. S. [Academy of Sciences of Belarus, Stepanov Institute of Physics, National (Belarus)
2015-12-15
The article presents a hardware and software complex for ground tests of onboard charged particle spectrometers that are designed at the National Research Nuclear University MEPhI for monitoring of nuclear-physical factors of space weather and can be installed in a wide class of satellites. The structural scheme and operating principles of component parts are discussed. The main algorithm and software features are presented. The technique of ground spectrometer tests and calibrations in various measurement modes at atmospheric cosmic particle flows, both in autonomous laboratories and in interface tests as part of a satellite, is also described.
Raznikova, M O; Raznikov, V V
2015-01-01
In this work, information relating to charge states of biomolecule ions in solution obtained using the electrospray ionization mass spectrometry of different biopolymers is analyzed. The data analyses have mainly been carried out by solving an inverse problem of calculating the probabilities of retention of protons and other charge carriers by ionogenic groups of biomolecules with known primary structures. The approach is a new one and has no known to us analogues. A program titled "Decomposition" was developed and used to analyze the charge distribution of ions of native and denatured cytochrome c mass spectra. The possibility of splitting of the charge-state distribution of albumin into normal components, which likely corresponds to various conformational states of the biomolecule, has been demonstrated. The applicability criterion for using previously described method of decomposition of multidimensional charge-state distributions with two charge carriers, e.g., a proton and a sodium ion, to characterize the spatial structure of biopolymers in solution has been formulated. In contrast to known mass-spectrometric approaches, this method does not require the use of enzymatic hydrolysis or collision-induced dissociation of the biopolymers.
Ground state correlations and mean field in 16O
Heisenberg, Jochen H.; Mihaila, Bogdan
1999-03-01
We use the coupled cluster expansion [exp(S) method] to generate the complete ground state correlations due to the NN interaction. Part of this procedure is the calculation of the two-body G matrix inside the nucleus in which it is being used. This formalism is being applied to 16O in a configuration space of 50ħω. The resulting ground state wave function is used to calculate the binding energy and one- and two-body densities for the ground state of 16O.
Ground state correlations and mean-field in $^{16}$O
Heisenberg, J H; Heisenberg, Jochen H.; Mihaila, Bogdan.
1999-01-01
We use the coupled cluster expansion ($\\exp(S)$ method) to generate the complete ground state correlations due to the $NN$ interaction. Part of this procedure is the calculation of the two-body ${\\mathbf G}$ matrix inside the nucleus in which it is being used. This formalism is being applied to $^{16}$O in a configuration space of 35 $\\hbar\\omega$. The resulting ground state wave function is used to calculate the binding energy and one- and two-body densities for the ground state of~$^{16}$O.
Classical ground states of symmetric Heisenberg spin systems
Schmidt, H J
2003-01-01
We investigate the ground states of classical Heisenberg spin systems which have point group symmetry. Examples are the regular polygons (spin rings) and the seven quasi-regular polyhedra including the five Platonic solids. For these examples, ground states with special properties, e.g. coplanarity or symmetry, can be completely enumerated using group-theoretical methods. For systems having coplanar (anti-) ground states with vanishing total spin we also calculate the smallest and largest energies of all states having a given total spin S. We find that these extremal energies depend quadratically on S and prove that, under certain assumptions, this happens only for systems with coplanar S = 0 ground states. For general systems the corresponding parabolas represent lower and upper bounds for the energy values. This provides strong support and clarifies the conditions for the so-called rotational band structure hypothesis which has been numerically established for many quantum spin systems.
Pineda, Nicolau; Rigo, Tomeu; Montanyà, Joan; van der Velde, Oscar A.
2016-09-01
The present study makes use of cloud-to-ground lightning, three-dimensional mapping from a Lightning Mapping Array and Doppler C-band radar observations to analyze the lightning trends and the underlying electrical charge structure of a large-hail bearing storm that produced important damages on the local agriculture. The analysis reported an extremely active storm, evolving through distinct phases, which stood out from a multicell structure to finally become a supercell. The onset of newer regions of convective development interacting with the main cell made the charge structure to be rather complex during some stages of this long-lived hailstorm. Evidence suggests the presence of regions with the charge layer being inverted from that of normal, non-severe convective storms, producing predominantly positive cloud-to-ground lightning. The analysis also suggests that strong cloud signals were misclassified as low peak current single-stroke negative cloud-to-ground flashes, masking the predominant positive nature of the storm.
Charge transfer state in DBP:C70 organic solar cells
Sherafatipour, Golenaz; Benduhn, Johannes; Spoltore, Donato
-acceptor interface via delocalized charge-transfer (CT) states, which represents an intermediate state between the exciton dissociation and recombination back to the ground state. In this work we perform the electroluminescence (EL) created by bimolecular free career recombination and sensitive external quantum....... Electroluminescence from charge transfer states in polymer solar cells. J. Am. Chem. Soc. 131, 11819–11824 (2009)....... efficiency measurements (sEQE) in DBP:C70 based SCs as a less studied system in order to study the energy and effect of CT states on degradation of the devices2. The results from these measurements reveal valuable information about the loss mechanism during the aging experiment as well as the energy...
Ground State Properties of the 1/2 Flux Harper Hamiltonian
Kennedy, Colin; Burton, William Cody; Chung, Woo Chang; Ketterle, Wolfgang
2015-05-01
The Harper Hamiltonian describes the motion of charged particles in an applied magnetic field - the spectrum of which exhibits the famed Hofstadter's butterfly. Recent advances in driven optical lattices have made great strides in simulating nontrivial Hamiltonians, such as the Harper model, in the time-averaged sense. We report on the realization of the ground state of bosons in the Harper Hamiltonian for 1/2 flux per plaquette utilizing a tilted two-dimensional lattice with laser assisted tunneling. We detail progress in studying various ground state properties of the 1/2 flux Harper Hamiltonian including ground state degeneracies, gauge-dependent observables, effects of micromotion, adiabatic loading schemes, and emergence and decay of coherence. Additionally, we describe prospects for flux rectification using a period-tripled superlattice and generalizations to three dimensions. MIT-Harvard Center for Ultracold Atoms, Research Laboratory of Electronics, Department of Physics, Massachusetts Institute of Technology.
Size of craters produced by explosive charges on or above the ground surface
Ambrosini, R. D.; Luccioni, B. M.; Danesi, R. F.; Riera, J. D.; Rocha, M. M.
The results of a series of tests performed with different amounts of explosive at short distances above and below ground level, as well as on the soil surface are briefly described. After an introductory description of both the main features of the blast wave and the mechanics of crater formation, a brief review of empirical methods for crater size prediction is presented. Next, the experimental design and the results obtained are described. The crater dimensions for underground explosions coincide with those found in the literature. For explosions at ground level the results are qualitatively described by empirical equations. For explosive charges situated above ground level, the dimensions of the craters are smaller than those observed in underground and near the surface explosions. Two new single prediction equations for this case are presented.
Ground state energy of the modified Nambu-Goto string
Hadasz, L
1998-01-01
We calculate, using zeta function regularization method, semiclassical energy of the Nambu-Goto string supplemented with the boundary, Gauss-Bonnet term in the action and discuss the tachyonic ground state problem.
Arsenic in Ground Water of the United States - Direct Download
U.S. Geological Survey, Department of the Interior — This image shows national-scale patterns of naturally occurring arsenic in potable ground-water resources of the continental United States. The image was generated...
ON GROUND STATE SOLUTIONS FOR SUPERLINEAR DIRAC EQUATION
张建; 唐先华; 张文
2014-01-01
This article is concerned with the nonlinear Dirac equations Under suitable assumptions on the nonlinearity, we establish the existence of ground state solutions by the generalized Nehari manifold method developed recently by Szulkin and Weth.
Entanglement of two ground state neutral atoms using Rydberg blockade
Miroshnychenko, Yevhen; Browaeys, Antoine; Evellin, Charles
2011-01-01
We report on our recent progress in trapping and manipulation of internal states of single neutral rubidium atoms in optical tweezers. We demonstrate the creation of an entangled state between two ground state atoms trapped in separate tweezers using the effect of Rydberg blockade. The quality of...
Borromean ground state of fermions in two dimensions
G. Volosniev, A.; V. Fedorov, D.; S. Jensen, A.;
2014-01-01
-body threshold. They are the lowest in a possible sequence of so-called super-Efimov states. While the observation of the super-Efimov scaling could be very difficult, the borromean ground state should be observable in cold atomic gases and could be the basis for producing a quantum gas of three-body states...
Theory of ground state factorization in quantum cooperative systems.
Giampaolo, Salvatore M; Adesso, Gerardo; Illuminati, Fabrizio
2008-05-16
We introduce a general analytic approach to the study of factorization points and factorized ground states in quantum cooperative systems. The method allows us to determine rigorously the existence, location, and exact form of separable ground states in a large variety of, generally nonexactly solvable, spin models belonging to different universality classes. The theory applies to translationally invariant systems, irrespective of spatial dimensionality, and for spin-spin interactions of arbitrary range.
Quasiparticle Random Phase Approximation with an optimal Ground State
Simkovic, F; Raduta, A A
2001-01-01
A new Quasiparticle Random Phase Approximation approach is presented. The corresponding ground state is variationally determined and exhibits a minimum energy. New solutions for the ground state, some with spontaneously broken symmetry, of a solvable Hamiltonian are found. A non-iterative procedure to solve the non-linear QRPA equations is used and thus all possible solutions are found. These are compared with the exact results as well as with the solutions provided by other approaches.
Santos, Javier; Bu, Xiu R.; Mintz, Eric A.
2001-01-01
The excited state charge transfer for a series of highly fluorescent dyes containing thiophenylimidazole moiety was investigated. These systems follow the Twisted Intramolecular Charge Transfer (TICT) model. Dual fluorescence was observed for each substituted dye. X-ray structures analysis reveals a twisted ground state geometry for the donor substituted aryl on the 4 and 5 position at the imidazole ring. The excited state charge transfer was modeled by a linear solvation energy relationship using Taft's pi and Dimroth's E(sub T)(30) as solvent parameters. There is linear relation between the energy of the fluorescence transition and solvent polarity. The degree of stabilization of the excited state charge transfer was found to be consistent with the intramolecular molecular charge transfer. Excited dipole moment was studied by utilizing the solvatochromic shift method.
Interfacial Charge Transfer States in Condensed Phase Systems
Vandewal, Koen
2016-05-01
Intermolecular charge transfer (CT) states at the interface between electron-donating (D) and electron-accepting (A) materials in organic thin films are characterized by absorption and emission bands within the optical gap of the interfacing materials. CT states efficiently generate charge carriers for some D-A combinations, and others show high fluorescence quantum efficiencies. These properties are exploited in organic solar cells, photodetectors, and light-emitting diodes. This review summarizes experimental and theoretical work on the electronic structure and interfacial energy landscape at condensed matter D-A interfaces. Recent findings on photogeneration and recombination of free charge carriers via CT states are discussed, and relations between CT state properties and optoelectronic device parameters are clarified.
An EBIS for charge state breeding in the SPES project
V Variale; G Brautti; T Clauser; A Rainò; V Stagno; G Lamanna; V Valentino; A Boggia; Y Boimelshtein; P Logatchov; B Skarbo; M Tiunov
2002-11-01
The ‘charge state breeder’, BRIC (breeding ion charge) is in construction at the INFN section of Bari (Italy). It is based on EBIS scheme and it is designed to accept radioactive ion beam (RIB) with charge state +1 in a slow injection mode. This experiment can be considered as a ﬁrst step towards the design and construction of a charge breeder for the SPES project. The new feature of BRIC, with respect to the classical EBIS, is given by the insertion, in the ion chamber, of a rf-quadrupole aiming at ﬁltering the unwanted masses and then making a more efﬁcient containment of the wanted ions. In this paper, the breeder design, the simulation results of the electron and ion beam propagation and the construction problems of the device will be reported.
Ground and Excited States Of OH(-)(H2O)n Clusters.
Zanuttini, David; Gervais, Benoit
2015-07-23
We present an ab initio study of OH(-)(H2O)n (n = 1-7) clusters in their lowest three singlet and two triplet electronic states, calculated with the RASPT2 method. Minimum energy structures were obtained by geometry optimization for both (a) the 1(1)Σ(+) ground state and (b) the 1(3)Π excited state. From these structures, vertical detachment energies (VDEs), transition energies, and atomic charges were calculated. (a) We found that ground-state geometries present the hydroxide at the surface, accepting three and four H bonds from water. The excess charge is strongly stabilized by water up to a VDE of 6.7 eV for n = 7. Bound singlet excited states for ground-state geometries exist for n ≥ 3, and their VDE increases up to 1 eV for n = 7. (b) The 1(3)Π state equilibrium geometries completely differ from the ground-state geometries. They are characterized by the hydroxide acting as a single H bond donor to a water molecule, which then donates a H-bond to two others, forming a "tree" pattern. All minimum energy structures present this "tree" pattern and a constant total number of 2n - 2 H bonds, or equivalently 3 dangling hydrogens. The excess charge stabilizes from n = 2 and goes mainly at the surface, on the dangling hydrogens of water. An almost neutral OH radical is then formed. Resulting structural resemblances with the neutral system make the VDEs of the first excited states weakly geometry dependent but size sensitive because of additive polarization effects. In contrast, the 1(1)Σ(+) state at the 1(3)Π geometries is strongly sensitive to structural patterns. We bring out existing correlations between these patterns and the corresponding 1(1)Σ(+) state energy increase, which leads to couplings with excited states and possibly to an inversion of the state energy order. From these assessments, we propose a scenario for recombination of aqueous hydroxide following excitation in a charge-transfer-to-solvent state.
Toward Triplet Ground State NaLi Molecules
Ebadi, Sepehr; Jamison, Alan; Rvachov, Timur; Jing, Li; Son, Hyungmok; Jiang, Yijun; Zwierlein, Martin; Ketterle, Wolfgang
2016-05-01
The NaLi molecule is expected to have a long lifetime in the triplet ground-state due to its fermionic nature, large rotational constant, and weak spin-orbit coupling. The triplet state has both electric and magnetic dipole moments, affording unique opportunities in quantum simulation and ultracold chemistry. We have mapped the excited state NaLi triplet potential by means of photoassociation spectroscopy. We report on this and our further progress toward the creation of the triplet ground-state molecules using STIRAP. NSF, ARO-MURI, Samsung, NSERC.
Efficient charge generation by relaxed charge-transfer states at organic interfaces
Vandewal, Koen; Albrecht, Steve; Hoke, Eric T.; Graham, Kenneth R.; Widmer, Johannes; Douglas, Jessica D.; Schubert, Marcel; Mateker, William R.; Bloking, Jason T.; Burkhard, George F.; Sellinger, Alan; Fréchet, Jean M. J.; Amassian, Aram; Riede, Moritz K.; McGehee, Michael D.; Neher, Dieter; Salleo, Alberto
2014-01-01
Interfaces between organic electron-donating (D) and electron-accepting (A) materials have the ability to generate charge carriers on illumination. Efficient organic solar cells require a high yield for this process, combined with a minimum of energy losses. Here, we investigate the role of the lowest energy emissive interfacial charge-transfer state (CT1) in the charge generation process. We measure the quantum yield and the electric field dependence of charge generation on excitation of the charge-transfer (CT) state manifold via weakly allowed, low-energy optical transitions. For a wide range of photovoltaic devices based on polymer:fullerene, small-molecule:C60 and polymer:polymer blends, our study reveals that the internal quantum efficiency (IQE) is essentially independent of whether or not D, A or CT states with an energy higher than that of CT1 are excited. The best materials systems show an IQE higher than 90% without the need for excess electronic or vibrational energy.
Efficient charge generation by relaxed charge-transfer states at organic interfaces
Vandewal, Koen
2013-11-17
Interfaces between organic electron-donating (D) and electron-accepting (A) materials have the ability to generate charge carriers on illumination. Efficient organic solar cells require a high yield for this process, combined with a minimum of energy losses. Here, we investigate the role of the lowest energy emissive interfacial charge-transfer state (CT1) in the charge generation process. We measure the quantum yield and the electric field dependence of charge generation on excitation of the charge-transfer (CT) state manifold via weakly allowed, low-energy optical transitions. For a wide range of photovoltaic devices based on polymer:fullerene, small-molecule:C60 and polymer:polymer blends, our study reveals that the internal quantum efficiency (IQE) is essentially independent of whether or not D, A or CT states with an energy higher than that of CT1 are excited. The best materials systems show an IQE higher than 90% without the need for excess electronic or vibrational energy. © 2014 Macmillan Publishers Limited.
Charge fluctuation, charge ordering, and zero-gap state in organic conductors
Takahashi, Toshihiro, E-mail: toshi.takahashi@gakushuin.ac.jp [Department of Physics, Gakushuin University, Mejiro 1-5-1, Toshima-ku, Tokyo 171-8588 (Japan)
2012-06-01
We have carried out a series of measurements of angular dependence of solid-state NMR spectrum using single crystal samples on various organic molecular conductors, in order to investigate the natures of the electronic states at low temperatures. We confirmed a charge ordered insulating state in {alpha}-(BEDT-TTF){sub 2}I{sub 3} and large charge disproportionation in the metallic state of this salt. In another charge ordered system, {theta}-(BEDT-TTF){sub 2}RbZn(SCN){sub 4}, we observed unusual NMR line broadening, proportional to resonance shift, in the metallic state above the transition. We found that this broadening is due to charge disproportionation, or more correctly, due to the inhomogeneity of local susceptibility at nuclear sites and analyzed its dynamics. We observed similar broadening in various organic molecular conductors as well, such as {theta}-(BEDT-TTF){sub 2}CsZn(SCN){sub 4}, an exotic Bechgaad salt, (TMTSF){sub 2}FSO{sub 3}, and {lambda}-type BETS salts, {lambda}-(BETS){sub 2}(Fe,Ga)Cl{sub 4}. We found the mechanism of CD in each system is different, respectively.
Long-range magnetic fields in the ground state of the Standard Model plasma
Boyarsky, Alexey; Shaposhnikov, Mikhail
2012-01-01
In thermal equilibrium the ground state of the plasma of Standard Model particles is determined by temperature and exactly conserved combinations of baryon and lepton numbers. We show that at non-zero values of the global charges a translation invariant and homogeneous state of the plasma becomes unstable and the system transits into a new state, containing a large-scale magnetic field. The origin of this effect is the parity-breaking character of weak interactions and chiral anomaly. This situation can occur in the early Universe and may play an important role in its subsequent evolution.
Long-Range Magnetic Fields in the Ground State of the Standard Model Plasma
Boyarsky, Alexey; Ruchayskiy, Oleg; Shaposhnikov, Mikhail
2012-09-01
In thermal equilibrium the ground state of the plasma of Standard Model particles is determined by temperature and exactly conserved combinations of baryon and lepton numbers. We show that at nonzero values of the global charges a translation invariant and homogeneous state of the plasma becomes unstable and the system transits into a new equilibrium state, containing a large-scale magnetic field. The origin of this effect is the parity-breaking character of weak interactions and chiral anomaly. This situation could occur in the early Universe and may play an important role in its subsequent evolution.
Charged anisotropic matter with linear or nonlinear equation of state
Varela, Victor; Ray, Saibal; Chakraborty, Kaushik; Kalam, Mehedi
2010-01-01
Ivanov pointed out substantial analytical difficulties associated with self-gravitating, static, isotropic fluid spheres when pressure explicitly depends on matter density. Simplification achieved with the introduction of electric charge were noticed as well. We deal with self-gravitating, charged, anisotropic fluids and get even more flexibility in solving the Einstein-Maxwell equations. In order to discuss analytical solutions we extend Krori and Barua's method to include pressure anisotropy and linear or non-linear equations of state. The field equations are reduced to a system of three algebraic equations for the anisotropic pressures as well as matter and electrostatic energy densities. Attention is paid to compact sources characterized by positive matter density and positive radial pressure. Arising solutions satisfy the energy conditions of general relativity. Spheres with vanishing net charge contain fluid elements with unbounded proper charge density located at the fluid-vacuum interface. Notably the...
Low-energy state-selective charge transfer by multiply charged ions
Lubinski, G; Juhasz, Z; Morgenstern, R; Hoekstra, R
2001-01-01
We present a combined rf-guided ion beam and photon emission spectroscopy method, which facilitates state-selective charge-transfer measurements at energies of direct relevance for astrophysics and fusion-plasma diagnostics and modeling. Ion energies have been varied from 1000 eV/amu down to energie
Ensemble Theory for Stealthy Hyperuniform Disordered Ground States
S. Torquato
2015-05-01
Full Text Available It has been shown numerically that systems of particles interacting with isotropic “stealthy” bounded long-ranged pair potentials (similar to Friedel oscillations have classical ground states that are (counterintuitively disordered, hyperuniform, and highly degenerate. Disordered hyperuniform systems have received attention recently because they are distinguishable exotic states of matter poised between a crystal and liquid that are endowed with novel thermodynamic and physical properties. The task of formulating an ensemble theory that yields analytical predictions for the structural characteristics and other properties of stealthy degenerate ground states in d-dimensional Euclidean space R^{d} is highly nontrivial because the dimensionality of the configuration space depends on the number density ρ and there is a multitude of ways of sampling the ground-state manifold, each with its own probability measure for finding a particular ground-state configuration. The purpose of this paper is to take some initial steps in this direction. Specifically, we derive general exact relations for thermodynamic properties (energy, pressure, and isothermal compressibility that apply to any ground-state ensemble as a function of ρ in any d, and we show how disordered degenerate ground states arise as part of the ground-state manifold. We also derive exact integral conditions that both the pair correlation function g_{2}(r and structure factor S(k must obey for any d. We then specialize our results to the canonical ensemble (in the zero-temperature limit by exploiting an ansatz that stealthy states behave remarkably like “pseudo”-equilibrium hard-sphere systems in Fourier space. Our theoretical predictions for g_{2}(r and S(k are in excellent agreement with computer simulations across the first three space dimensions. These results are used to obtain order metrics, local number variance, and nearest-neighbor functions across dimensions. We also derive
Ensemble Theory for Stealthy Hyperuniform Disordered Ground States
Torquato, S.; Zhang, G.; Stillinger, F. H.
2015-04-01
It has been shown numerically that systems of particles interacting with isotropic "stealthy" bounded long-ranged pair potentials (similar to Friedel oscillations) have classical ground states that are (counterintuitively) disordered, hyperuniform, and highly degenerate. Disordered hyperuniform systems have received attention recently because they are distinguishable exotic states of matter poised between a crystal and liquid that are endowed with novel thermodynamic and physical properties. The task of formulating an ensemble theory that yields analytical predictions for the structural characteristics and other properties of stealthy degenerate ground states in d -dimensional Euclidean space Rd is highly nontrivial because the dimensionality of the configuration space depends on the number density ρ and there is a multitude of ways of sampling the ground-state manifold, each with its own probability measure for finding a particular ground-state configuration. The purpose of this paper is to take some initial steps in this direction. Specifically, we derive general exact relations for thermodynamic properties (energy, pressure, and isothermal compressibility) that apply to any ground-state ensemble as a function of ρ in any d , and we show how disordered degenerate ground states arise as part of the ground-state manifold. We also derive exact integral conditions that both the pair correlation function g2(r ) and structure factor S (k ) must obey for any d . We then specialize our results to the canonical ensemble (in the zero-temperature limit) by exploiting an ansatz that stealthy states behave remarkably like "pseudo"-equilibrium hard-sphere systems in Fourier space. Our theoretical predictions for g2(r ) and S (k ) are in excellent agreement with computer simulations across the first three space dimensions. These results are used to obtain order metrics, local number variance, and nearest-neighbor functions across dimensions. We also derive accurate analytical
Photoemission spectra of charge density wave states in cuprates
Tu, Wei-Lin; Chen, Peng-Jen; Lee, Ting-Kuo
Angle-resolved photoemission spectroscopy(ARPES) experiments have reported many exotic properties of cuprates, such as Fermi arc at normal state, two gaps at superconducting state and particle-hole asymmetry at the antinodal direction. On the other hand, a number of inhomogeneous states or so-called charge density waves(CDW) states have also been discovered in cuprates by many experimental groups. The relation between these CDW states and ARPES spectra is unclear. With the help of Gutzwiller projected mean-field theory, we can reproduce the quasiparticle spectra in momentum space. The spectra show strong correspondence to the experimental data with afore-mentioned exotic features in it.
Ground state correlations and mean field in 16O. II. Effects of a three-nucleon interaction
Mihaila, Bogdan; Heisenberg, Jochen H.
2000-05-01
We continue the investigations of the 16O ground state using the coupled-cluster expansion [exp(S)] method with realistic nuclear interaction. In this stage of the project, we take into account the three nucleon interaction, and examine in some detail the definition of the internal Hamiltonian, thus trying to correct for the center-of-mass motion. We show that this may result in a better separation of the internal and center-of-mass degrees of freedom in the many-body nuclear wave function. The resulting ground state wave function is used to calculate the ``theoretical'' charge form factor and charge density. Using the ``theoretical'' charge density, we generate the charge form factor in the DWBA picture, which is then compared with the available experimental data. The longitudinal response function in inclusive electron scattering for 16O is also computed.
Quench of a symmetry-broken ground state
Giampaolo, S. M.; Zonzo, G.
2017-01-01
We analyze the problem of how different ground states associated with the same set of Hamiltonian parameters evolve after a sudden quench. To realize our analysis we define a quantitative approach to the local distinguishability between different ground states of a magnetically ordered phase in terms of the trace distance between the reduced density matrices obtained by projecting two ground states in the same subset. Before the quench, regardless of the particular choice of subset, any system in a magnetically ordered phase is characterized by ground states that are locally distinguishable. On the other hand, after the quench, the maximum distinguishability shows an exponential decay in time. Hence, in the limit of very long times, all the information about the particular initial ground state is lost even if the systems are integrable. We prove our claims in the framework of the magnetically ordered phases that characterize both the X Y and the N -cluster Ising models. The fact that we find similar behavior in models within different classes of symmetry makes us confident about the generality of our results.
Borromean ground state of fermions in two dimensions
Volosniev, A. G.; Fedorov, D. V.; Jensen, A. S.; Zinner, N. T.
2014-09-01
The study of quantum mechanical bound states is as old as quantum theory itself. Yet, it took many years to realize that three-body Borromean systems that are bound when any two-body subsystem is unbound are abundant in nature. Here we demonstrate the existence of Borromean systems of spin-polarized (spinless) identical fermions in two spatial dimensions. The ground state with zero orbital (planar) angular momentum exists in a Borromean window between critical two- and three-body strengths. The doubly degenerate first excited states of angular momentum one appears only very close to the two-body threshold. They are the lowest in a possible sequence of so-called super-Efimov states. While the observation of the super-Efimov scaling could be very difficult, the Borromean ground state should be observable in cold atomic gases and could be the basis for producing a quantum gas of three-body states in two dimensions.
Universal state-of-charge indication for portable applications
Pop, V.
2007-01-01
Many leading semiconductors companies (e.g. Philips, Texas Instruments, Microchip, Maxim, etc.) are paying even more attention to accurate State-of-Charge (SoC) indication. Following the technological revolution and the appearance of more power consuming devices on the automotive electronics and por
State-of-Charge Indication in Portable Applications
Pop, V.; Bergveld, H.J.; Notten, P.H.L.; Regtien, Paulus P.L.
2005-01-01
The known methods of state-of-charge (SoC) indication in portable applications are not accurate enough under all practical conditions. The method presented in this paper aims at designing and testing an SoC indication system capable of predicting the remaining capacity of the battery and the
Protecting a Diamond Quantum Memory by Charge State Control.
Pfender, Matthias; Aslam, Nabeel; Simon, Patrick; Antonov, Denis; Thiering, Gergő; Burk, Sina; Fávaro de Oliveira, Felipe; Denisenko, Andrej; Fedder, Helmut; Meijer, Jan; Garrido, Jose A; Gali, Adam; Teraji, Tokuyuki; Isoya, Junichi; Doherty, Marcus William; Alkauskas, Audrius; Gallo, Alejandro; Grüneis, Andreas; Neumann, Philipp; Wrachtrup, Jörg
2017-09-11
In recent years, solid-state spin systems have emerged as promising candidates for quantum information processing. Prominent examples are the nitrogen-vacancy (NV) center in diamond, phosphorus dopants in silicon (Si:P), rare-earth ions in solids, and VSi-centers in silicon-carbide. The Si:P system has demonstrated that its nuclear spins can yield exceedingly long spin coherence times by eliminating the electron spin of the dopant. For NV centers, however, a proper charge state for storage of nuclear spin qubit coherence has not been identified yet. Here, we identify and characterize the positively charged NV center as an electron-spin-less and optically inactive state by utilizing the nuclear spin qubit as a probe. We control the electronic charge and spin utilizing nanometer scale gate electrodes. We achieve a lengthening of the nuclear spin coherence times by a factor of 4. Surprisingly, the new charge state allows switching of the optical response of single nodes facilitating full individual addressability.
Modeling Battery Behavior for Accurate State-of-Charge Indication
Pop, V.; Bergveld, H.J.; Veld, op het J.H.G.; Regtien, P.P.L.; Danilov, D.; Notten, P.H.L.
2006-01-01
Li-ion is the most commonly used battery chemistry in portable applications nowadays. Accurate state-of-charge (SOC) and remaining run-time indication for portable devices is important for the user's convenience and to prolong the lifetime of batteries. A new SOC indication system, combining the ele
Charged Cylindrical Polytropes with Generalized Polytropic Equation of State
Azam, M; Noureen, I; Rehman, M A
2016-01-01
We study the general formalism of polytropes in relativistic regime with generalized polytropic equations of state in the vicinity of cylindrical symmetry. We take charged anisotropic fluid distribution of matter with conformally flat condition for the development of general framework of polytropes. We discussed the stability of the model by Whittaker formula and concluded that one of the developed model is physically viable.
State selective capture by highly charged Xe ions
Hasan, V. G.; Knoop, S.; Morgenstern, R.; Hoekstra, R.; McCullough, RW; Currell, FJ; Greenwood, J; Gribakin, G; Scott, MP
2007-01-01
Single-electron capture in collisions of highly charged ions Xe18+ and Xe24+ with Na atoms is investigated by measuring the momenta of the Na recoil ions. The Q-value spectrum in Xe18+ + Na collisions shows capture into lower n states compared with Classical over-barrier model (CBM) calculations.
Universal state-of-charge indication for portable applications
Pop, V.
2007-01-01
Many leading semiconductors companies (e.g. Philips, Texas Instruments, Microchip, Maxim, etc.) are paying even more attention to accurate State-of-Charge (SoC) indication. Following the technological revolution and the appearance of more power consuming devices on the automotive electronics and por
Fast electronic resistance switching involving hidden charge density wave states
Vaskivskyi, I.; Mihailovic, I. A.; Brazovskii, S.; Gospodaric, J.; Mertelj, T.; Svetin, D.; Sutar, P.; Mihailovic, D.
2016-05-01
The functionality of computer memory elements is currently based on multi-stability, driven either by locally manipulating the density of electrons in transistors or by switching magnetic or ferroelectric order. Another possibility is switching between metallic and insulating phases by the motion of ions, but their speed is limited by slow nucleation and inhomogeneous percolative growth. Here we demonstrate fast resistance switching in a charge density wave system caused by pulsed current injection. As a charge pulse travels through the material, it converts a commensurately ordered polaronic Mott insulating state in 1T-TaS2 to a metastable electronic state with textured domain walls, accompanied with a conversion of polarons to band states, and concurrent rapid switching from an insulator to a metal. The large resistance change, high switching speed (30 ps) and ultralow energy per bit opens the way to new concepts in non-volatile memory devices manipulating all-electronic states.
Ferromagnetic Ground States in Face-Centered Cubic Hubbard Clusters
Souza, T. X. R.; Macedo, C. A.
2016-01-01
In this study, the ground state energies of face-centered cubic Hubbard clusters are analyzed using the Lanczos method. Examination of the ground state energy as a function of the number of particle per site n showed an energy minimum for face-centered cubic structures. This energy minimum decreased in n with increasing coulombic interaction parameter U. We found that the ground state energy had a minimum at n = 0.6, when U = 3W, where W denotes the non-interacting energy bandwidth and the face-centered cubic structure was ferromagnetic. These results, when compared with the properties of nickel, shows strong similarity with other finite temperature analyses in the literature and supports the Hirsh’s conjecture that the interatomic direct exchange interaction dominates in driving the system into a ferromagnetic phase. PMID:27583653
Estimation of beryllium ground state energy by Monte Carlo simulation
Kabir, K. M. Ariful [Department of Physical Sciences, School of Engineering and Computer Science, Independent University, Bangladesh (IUB) Dhaka (Bangladesh); Halder, Amal [Department of Mathematics, University of Dhaka Dhaka (Bangladesh)
2015-05-15
Quantum Monte Carlo method represent a powerful and broadly applicable computational tool for finding very accurate solution of the stationary Schrödinger equation for atoms, molecules, solids and a variety of model systems. Using variational Monte Carlo method we have calculated the ground state energy of the Beryllium atom. Our calculation are based on using a modified four parameters trial wave function which leads to good result comparing with the few parameters trial wave functions presented before. Based on random Numbers we can generate a large sample of electron locations to estimate the ground state energy of Beryllium. Our calculation gives good estimation for the ground state energy of the Beryllium atom comparing with the corresponding exact data.
Probing quantum frustrated systems via factorization of the ground state.
Giampaolo, Salvatore M; Adesso, Gerardo; Illuminati, Fabrizio
2010-05-21
The existence of definite orders in frustrated quantum systems is related rigorously to the occurrence of fully factorized ground states below a threshold value of the frustration. Ground-state separability thus provides a natural measure of frustration: strongly frustrated systems are those that cannot accommodate for classical-like solutions. The exact form of the factorized ground states and the critical frustration are determined for various classes of nonexactly solvable spin models with different spatial ranges of the interactions. For weak frustration, the existence of disentangling transitions determines the range of applicability of mean-field descriptions in biological and physical problems such as stochastic gene expression and the stability of long-period modulated structures.
Analysis of ground state in random bipartite matching
Shi, Gui-Yuan; Liao, Hao; Zhang, Yi-Cheng
2015-01-01
In human society, a lot of social phenomena can be concluded into a mathematical problem called the bipartite matching, one of the most well known model is the marriage problem proposed by Gale and Shapley. In this article, we try to find out some intrinsic properties of the ground state of this model and thus gain more insights and ideas about the matching problem. We apply Kuhn-Munkres Algorithm to find out the numerical ground state solution of the system. The simulation result proves the previous theoretical analysis using replica method. In the result, we also find out the amount of blocking pairs which can be regarded as a representative of the system stability. Furthermore, we discover that the connectivity in the bipartite matching problem has a great impact on the stability of the ground state, and the system will become more unstable if there were more connections between men and women.
Study of polonium isotopes ground state properties by simultaneous atomic- and nuclear-spectroscopy
Koester, U H; Kalaninova, Z; Imai, N
2007-01-01
We propose to systematically study the ground state properties of neutron deficient $^{192-200}$Po isotopes by means of in-source laser spectroscopy using the ISOLDE laser ion source coupled with nuclear spectroscopy at the detection setup as successfully done before by this collaboration with neutron deficient lead isotopes. The study of the change in mean square charge radii along the polonium isotope chain will give an insight into shape coexistence above the mid-shell N = 104 and above the closed shell Z = 82. The hyperfine structure of the odd isotopes will also allow determination of the nuclear spin and the magnetic moment of the ground state and of any identifiable isomer state. For this study, a standard UC$_{x}$ target with the ISOLDE RILIS is required for 38 shifts.
Ground-State Cooling of a Mechanical Oscillator by Interference in Andreev Reflection
Stadler, P.; Belzig, W.; Rastelli, G.
2016-11-01
We study the ground-state cooling of a mechanical oscillator linearly coupled to the charge of a quantum dot inserted between a normal metal and a superconducting contact. Such a system can be realized, e.g., by a suspended carbon nanotube quantum dot with a capacitive coupling to a gate contact. Focusing on the subgap transport regime, we analyze the inelastic Andreev reflections which drive the resonator to a nonequilibrium state. For small coupling, we obtain that vibration-assisted reflections can occur through two distinct interference paths. The interference determines the ratio between the rates of absorption and emission of vibrational energy quanta. We show that ground-state cooling of the mechanical oscillator can be achieved for many of the oscillator's modes simultaneously or for single modes selectively, depending on the experimentally tunable coupling to the superconductor.
Ground states of the SU(N) Heisenberg model.
Kawashima, Naoki; Tanabe, Yuta
2007-02-02
The SU(N) Heisenberg model with various single-row representations is investigated by quantum Monte Carlo simulations. While the zero-temperature phase boundary agrees qualitatively with the theoretical predictions based on the 1/N expansion, some unexpected features are also observed. For N> or =5 with the fundamental representation, for example, it is suggested that the ground states possess exact or approximate U(1) degeneracy. In addition, for the representation of Young tableau with more than one column, the ground state shows no valence-bond-solid order even at N greater than the threshold value.
Ground state properties of graphene in Hartree-Fock theory
Hainzl, Christian; Sparber, Christof
2012-01-01
We study the Hartree-Fock approximation of graphene in infinite volume, with instantaneous Coulomb interactions. First we construct its translation-invariant ground state and we recover the well-known fact that, due to the exchange term, the effective Fermi velocity is logarithmically divergent at zero momentum. In a second step we prove the existence of a ground state in the presence of local defects and we discuss some properties of the linear response to an external electric field. All our results are non perturbative.
Coherent Control of Ground State NaK Molecules
Yan, Zoe; Park, Jee Woo; Loh, Huanqian; Will, Sebastian; Zwierlein, Martin
2016-05-01
Ultracold dipolar molecules exhibit anisotropic, tunable, long-range interactions, making them attractive for the study of novel states of matter and quantum information processing. We demonstrate the creation and control of 23 Na40 K molecules in their rovibronic and hyperfine ground state. By applying microwaves, we drive coherent Rabi oscillations of spin-polarized molecules between the rotational ground state (J=0) and J=1. The control afforded by microwave manipulation allows us to pursue engineered dipolar interactions via microwave dressing. By driving a two-photon transition, we are also able to observe Ramsey fringes between different J=0 hyperfine states, with coherence times as long as 0.5s. The realization of long coherence times between different molecular states is crucial for applications in quantum information processing. NSF, AFOSR- MURI, Alfred P. Sloan Foundation, DARPA-OLE
Ground-State Transition in a Two-Dimensional Frenkel-Kontorova Model
YUAN Xiao-Ping; ZHENG Zhi-Gang
2011-01-01
The ground state of a generalized Frenkel-Kontorova model with a transversaJ degree of freedom is studied. When the coupling strength, K, and the frequency of & single-Atom vibration in the transversaJ direction, ωou are increased, the ground state of the model undergoes a transition from a two-dimensional configuration to a one-dimensional one. This transition can manifest in different ways. Furthermore, we find that the prerequisite of a two-dimensionai ground state is θ≠1//q.%The ground state of a generalized Frenkel-Kontorova model with a transversal degree of freedom is studied.When the coupling strength,K,and the frequency of a single-atom vibration in the transversal direction,ωoy,are increased,the ground state of the model undergoes a transition from a two-dimensional configuration to a one-dimensional one.This transition can manifest in different ways.Furthermore,we find that the prerequisite of a two-dimensional ground state is θ ≠ 1/q.In recent years,the Frenkel-Kontorova (FK) model has been applied to a variety of physical systems,such as adsorbed monolayers,[1,2] Josephsonjunction arrays,[3-5] tribology[6-8] and charge-density waves.[9,10] Experimental and large-scale simulation data at the nanoscale have become available,and more complicated FK-type models have been investigated using simulations of molecular dynamics.[11
Ground-state properties of ordered, partially ordered, and random Cu-Au and Ni-Pt alloys
Ruban, Andrei; Abrikosov, I. A.; Skriver, Hans Lomholt
1995-01-01
We have studied the ground-state properties of ordered, partially ordered, and random Cu-Au and Ni-Pt alloys at the stoichiometric 1/4, 1/2, and 3/4 compositions in the framework of the multisublattice single-site (SS) coherent potential approximation (CPA). Charge-transfer effects in the random ...
Ultrafast pump-probe study of the excited-state charge-transfer dynamics in blue copper rusticyanin.
Bizzarri, Anna Rita; Brida, Daniele; Santini, Simona; Cerullo, Giulio; Cannistraro, Salvatore
2012-04-12
We have used femtosecond pump-probe spectroscopy to investigate the excited-state dynamics of the anticancer blue copper protein rusticyanin, by exciting its ligand to metal charge-transfer band with 25 fs pump pulses centered at 585 nm. The charge-transfer excited state decays exponentially to the ground state with a time constant of about 230 fs, and its recovery is modulated by coherent oscillations. The Fourier transform of the oscillatory component of the signal provides most of the vibrational modes obtained by means of conventional resonance Raman studies, in addition to the low frequency modes below 80 cm(-1) believed to reflect collective motions of biological relevance.
Logan D Andrews
2013-07-01
Full Text Available Enzymes stabilize transition states of reactions while limiting binding to ground states, as is generally required for any catalyst. Alkaline Phosphatase (AP and other nonspecific phosphatases are some of Nature's most impressive catalysts, achieving preferential transition state over ground state stabilization of more than 10²²-fold while utilizing interactions with only the five atoms attached to the transferred phosphorus. We tested a model that AP achieves a portion of this preference by destabilizing ground state binding via charge repulsion between the anionic active site nucleophile, Ser102, and the negatively charged phosphate monoester substrate. Removal of the Ser102 alkoxide by mutation to glycine or alanine increases the observed Pi affinity by orders of magnitude at pH 8.0. To allow precise and quantitative comparisons, the ionic form of bound P(i was determined from pH dependencies of the binding of Pi and tungstate, a P(i analog lacking titratable protons over the pH range of 5-11, and from the ³¹P chemical shift of bound P(i. The results show that the Pi trianion binds with an exceptionally strong femtomolar affinity in the absence of Ser102, show that its binding is destabilized by ≥10⁸-fold by the Ser102 alkoxide, and provide direct evidence for ground state destabilization. Comparisons of X-ray crystal structures of AP with and without Ser102 reveal the same active site and P(i binding geometry upon removal of Ser102, suggesting that the destabilization does not result from a major structural rearrangement upon mutation of Ser102. Analogous Pi binding measurements with a protein tyrosine phosphatase suggest the generality of this ground state destabilization mechanism. Our results have uncovered an important contribution of anionic nucleophiles to phosphoryl transfer catalysis via ground state electrostatic destabilization and an enormous capacity of the AP active site for specific and strong recognition of the
Striped spin liquid crystal ground state instability of kagome antiferromagnets.
Clark, Bryan K; Kinder, Jesse M; Neuscamman, Eric; Chan, Garnet Kin-Lic; Lawler, Michael J
2013-11-01
The Dirac spin liquid ground state of the spin 1/2 Heisenberg kagome antiferromagnet has potential instabilities. This has been suggested as the reason why it does not emerge as the ground state in large-scale numerical calculations. However, previous attempts to observe these instabilities have failed. We report on the discovery of a projected BCS state with lower energy than the projected Dirac spin liquid state which provides new insight into the stability of the ground state of the kagome antiferromagnet. The new state has three remarkable features. First, it breaks spatial symmetry in an unusual way that may leave spinons deconfined along one direction. Second, it breaks the U(1) gauge symmetry down to Z(2). Third, it has the spatial symmetry of a previously proposed "monopole" suggesting that it is an instability of the Dirac spin liquid. The state described herein also shares a remarkable similarity to the distortion of the kagome lattice observed at low Zn concentrations in Zn-paratacamite and in recently grown single crystals of volborthite suggesting it may already be realized in these materials.
Asymptotics of Ground State Degeneracies in Quiver Quantum Mechanics
Cordova, Clay
2015-01-01
We study the growth of the ground state degeneracy in the Kronecker model of quiver quantum mechanics. This is the simplest quiver with two gauge groups and bifundamental matter fields, and appears universally in the context of BPS state counting in four-dimensional N=2 systems. For large ranks, the ground state degeneracy is exponential with slope a modular function that we are able to compute at integral values of its argument. We also observe that the exponential of the slope is an algebraic number and determine its associated algebraic equation explicitly in several examples. The speed of growth of the degeneracies, together with various physical features of the bound states, suggests a dual string interpretation.
Macroscopic Greenberg-Horne-Zeilinger state and W state in charge qubits based on Coulomb blockade
Liang, L. M.; Wang, X. B.
2010-03-01
Based on Coulomb blockade, we propose a scheme to generate two types of three-qubit entanglement, known as Greenberg-Horne-Zeilinger (GHZ) state and W state, in a macroscopic quantum system. The qubit is encoded in the charge qubit in the superconducting system, and the scheme can be generalized to generate the GHZ state and W state in multi-partite charge qubits. The GHZ state and W state are the eigenstates of the respective idle Hamiltonian, so they have the long lifetime.
Observation of Hyperfine Transitions in Trapped Ground-State Antihydrogen
Olin, Arthur
2015-01-01
This paper discusses the first observation of stimulated magnetic resonance transitions between the hyperfine levels of trapped ground state atomic antihydrogen, confirming its presence in the ALPHA apparatus. Our observations show that these transitions are consistent with the values in hydrogen to within 4~parts~in~$10^3$. Simulations of the trapped antiatoms in a microwave field are consistent with our measurements.
Advantages of Unfair Quantum Ground-State Sampling.
Zhang, Brian Hu; Wagenbreth, Gene; Martin-Mayor, Victor; Hen, Itay
2017-04-21
The debate around the potential superiority of quantum annealers over their classical counterparts has been ongoing since the inception of the field. Recent technological breakthroughs, which have led to the manufacture of experimental prototypes of quantum annealing optimizers with sizes approaching the practical regime, have reignited this discussion. However, the demonstration of quantum annealing speedups remains to this day an elusive albeit coveted goal. We examine the power of quantum annealers to provide a different type of quantum enhancement of practical relevance, namely, their ability to serve as useful samplers from the ground-state manifolds of combinatorial optimization problems. We study, both numerically by simulating stoquastic and non-stoquastic quantum annealing processes, and experimentally, using a prototypical quantum annealing processor, the ability of quantum annealers to sample the ground-states of spin glasses differently than thermal samplers. We demonstrate that (i) quantum annealers sample the ground-state manifolds of spin glasses very differently than thermal optimizers (ii) the nature of the quantum fluctuations driving the annealing process has a decisive effect on the final distribution, and (iii) the experimental quantum annealer samples ground-state manifolds significantly differently than thermal and ideal quantum annealers. We illustrate how quantum annealers may serve as powerful tools when complementing standard sampling algorithms.
On the Ground State Wave Function of Matrix Theory
Lin, Ying-Hsuan
2014-01-01
We propose an explicit construction of the leading terms in the asymptotic expansion of the ground state wave function of BFSS SU(N) matrix quantum mechanics. Our proposal is consistent with the expected factorization property in various limits of the Coulomb branch, and involves a different scaling behavior from previous suggestions. We comment on some possible physical implications.
On the ground state wave function of matrix theory
Lin, Ying-Hsuan; Yin, Xi
2015-11-01
We propose an explicit construction of the leading terms in the asymptotic expansion of the ground state wave function of BFSS SU( N ) matrix quantum mechanics. Our proposal is consistent with the expected factorization property in various limits of the Coulomb branch, and involves a different scaling behavior from previous suggestions. We comment on some possible physical implications.
^{66}Ga ground state β spectrum
Severin, Gregory; Knutson, L. D.; Voytas, P. A.;
2014-01-01
The ground state branch of the β decay of 66Ga is an allowed Fermi (0+ → 0+) transition with a relatively high f t value. The large f t and the isospin-forbidden nature of the transition indicates that the shape of the β spectrum of this branch may be sensitive to higher order contributions...
Magnetic excitons in singlet-ground-state ferromagnets
Birgeneau, R.J.; Als-Nielsen, Jens Aage; Bucher, E.
1971-01-01
The authors report measurements of the dispersion of singlet-triplet magnetic excitons as a function of temperature in the singlet-ground-state ferromagnets fcc Pr and Pr3Tl. Well-defined excitons are observed in both the ferromagnetic and paramagnetic regions, but with energies which are nearly...
Vo, Thanh Tu; Chen, Xiaopeng; Shen, Weixiang; Kapoor, Ajay
2015-01-01
In this paper, a new charging strategy of lithium-polymer batteries (LiPBs) has been proposed based on the integration of Taguchi method (TM) and state of charge estimation. The TM is applied to search an optimal charging current pattern. An adaptive switching gain sliding mode observer (ASGSMO) is adopted to estimate the SOC which controls and terminates the charging process. The experimental results demonstrate that the proposed charging strategy can successfully charge the same types of LiPBs with different capacities and cycle life. The proposed charging strategy also provides much shorter charging time, narrower temperature variation and slightly higher energy efficiency than the equivalent constant current constant voltage charging method.
Influence of free carriers on exciton ground states in quantum wells
Klochikhin, A.A. [Ioffe Physical Technical Institute, 194021 St. Petersburg (Russian Federation); Nuclear Physics Institute, 350000 St. Petersburg (Russian Federation); Kochereshko, V.P., E-mail: vladimir.kochereshko@mail.ioffe.ru [Ioffe Physical Technical Institute, 194021 St. Petersburg (Russian Federation); Spin Optics Laboratory, St. Petersburg State University, 198904 St. Petersburg (Russian Federation); Tatarenko, S. [CEA-CNRS Group “Nanophysique et Semiconducteurs”, Institut Néel, CNRS and Universite Joseph Fourier, 25 Avenue des Martyrs, 38042 Grenoble (France)
2014-10-15
The influence of free carriers on the ground state of the exciton at zero magnetic field in a quasi-two-dimensional quantum well that contains a gas of free electrons is considered in the framework of the random phase approximation. The effects of the exciton–charge-density interaction and the inelastic scattering processes due to the electron–electron exchange interaction are taken into account. The effect of phase-space filling is considered using an approximate approach. The results of the calculation are compared with the experimental data. - Highlights: • We discussed the effect of free carriers on the exciton ground state in quantum wells. • The processes of exciton–electron scattering become the most important for excitons in doped QWs. • The direct Coulomb scattering can be neglected. • The most important becomes the exchange inelastic exciton–electron scattering.
Charged cylindrical polytropes with generalized polytropic equation of state
Azam, M. [University of Education, Division of Science and Technology, Lahore (Pakistan); Mardan, S.A.; Noureen, I.; Rehman, M.A. [University of the Management and Technology, Department of Mathematics, Lahore (Pakistan)
2016-09-15
We study the general formalism of polytropes in the relativistic regime with generalized polytropic equations of state in the vicinity of cylindrical symmetry. We take a charged anisotropic fluid distribution of matter with a conformally flat condition for the development of a general framework of the polytropes. We discuss the stability of the model by the Whittaker formula and conclude that one of the models developed is physically viable. (orig.)
Charged cylindrical polytropes with generalized polytropic equation of state
Azam, M.; Mardan, S. A.; Noureen, I.; Rehman, M. A.
2016-09-01
We study the general formalism of polytropes in the relativistic regime with generalized polytropic equations of state in the vicinity of cylindrical symmetry. We take a charged anisotropic fluid distribution of matter with a conformally flat condition for the development of a general framework of the polytropes. We discuss the stability of the model by the Whittaker formula and conclude that one of the models developed is physically viable.
Ground and excited states for exotic three-body atomic systems
Gasaneo G.
2010-04-01
Full Text Available An Angular Correlated Conﬁguration Interaction method is extended and applied to exotic threebody atomic systems with general masses. A recently proposed angularly correlated basis set is used to construct, simultaneously and with a single diagonalization, ground and excited states wave functions which: (i satisfy exactly Kato cusp conditions at the two-body coalescence points; (ii have only linear parameters; (iii show a fast convergency rate for the energy; (iv form an orthogonal set. The eﬃciency of the construction is illustrated by the study a variety of three-body atomic systems [m1− m2− m3z3+ ] with two negatively charged light particles, with 123 diverse masses m1− and m2−, and a heavy positively charged nucleus m3z3+. The calculated ground 11S and several excited n1,3S state energies are compared with those given in the literature, when available. We also present a short discussion on the critical charge necessary to get a stable three-body system supporting two electrons, an electron and a muon, or two muons.
Collective excitations, instabilities, and ground state in dense quark matter
Gorbar, E V; Miransky, V A; Shovkovy, I A; Hashimoto, Michio
2006-01-01
We study the spectrum of light plasmons in the (gapped and gapless) two-flavor color superconducting phases and its connection with the chromomagnetic instabilities and the structure of the ground state. It is revealed that the chromomagnetic instabilities in the 4-7th and 8th gluonic channels correspond to two very different plasmon spectra. These spectra lead us to the unequivocal conclusion about the existence of gluonic condensates (some of which can be spatially inhomogeneous) in the ground state. We also argue that spatially inhomogeneous gluonic condensates should exist in the three-flavor quark matter with the values of the mass of strange quark corresponding to the gapless color-flavor locked state.
Fate of the Superconducting Ground State on the Moyal Plane
Basu, Prasad; Vaidya, Sachindeo
2009-01-01
It is known that Berry curvature of the band structure of certain crystals can lead to effective noncommutativity between spatial coordinates. Using the techniques of twisted quantum field theory, we investigate the question of the formation of a paired state of twisted fermions in such a system. We find that to leading order in the noncommutativity parameter, the gap between the non-interacting ground state and the paired state is {\\it smaller} compared to its commutative counterpart. This suggests that BCS type superconductivity, if present in such systems, is more fragile and easier to disrupt.
Charge Order Induced in an Orbital Density-Wave State
Singh, Dheeraj Kumar; Takimoto, Tetsuya
2016-04-01
Motivated by recent angle resolved photoemission measurements [D. V. Evtushinsky et al., Phys. Rev. Lett. 105, 147201 (2010)] and evidence of the density-wave state for the charge and orbital ordering [J. García et al., Phys. Rev. Lett. 109, 107202 (2012)] in La0.5Sr1.5MnO4, the issue of charge and orbital ordering in a two-orbital tight-binding model for layered manganite near half doping is revisited. We find that the charge order with the ordering wavevector 2{Q} = (π ,π ) is induced by the orbital order of d-/d+-type having B1g representation with a different ordering wavevector Q, where the orbital order as the primary order results from the strong Fermi-surface nesting. It is shown that the induced charge order parameter develops according to TCO - T by decreasing the temperature below the orbital ordering temperature TCO, in addition to the usual mean-field behavior of the orbital order parameter. Moreover, the same orbital order is found to stabilize the CE-type spin arrangement observed experimentally below TCE < TCO.
Projectile charge state dependent sputtering of solid surfaces
Hayderer, G
2000-01-01
dependence on the ion kinetic energy. This new type of potential sputtering not only requires electronic excitation of the target material, but also the formation of a collision cascade within the target in order to initiate the sputtering process and has therefore been termed kinetically assisted potential sputtering. In order to study defects induced by potential sputtering on the atomic scale we performed measurements of multiply charged Ar ion irradiated HOPG (highly oriented pyrolitic graphite) samples with scanning tunneling microscopy (STM). The only surface defects found in the STM images are protrusions. The mean diameter of the defects increases with projectile charge state while the height of the protrusions stays roughly the same indicating a possible pre-equilibrium effect of the stopping of slow multiply charged projectiles in HOPG. Total sputter yields for impact of slow singly and multiply charged ions on metal- (Au), oxide- (Al2O3, MgO) and alkali-halide surfaces (LiF) have been measured as a...
Mixed configuration ground state in iron(II) phthalocyanine
Fernandez-Rodriguez, Javier; Toby, Brian; van Veenendaal, Michel
2015-06-23
We calculate the angular dependence of the x-ray linear and circular dichroism at the L2,3 edges of α-Fe(II) Phthalocyanine (FePc) thin films using a ligand-field model with full configuration interaction. We find the best agreement with the experimental spectra for a mixed ground state of 3E (a2 e3b1 ) and 3B (a1 e4b1 ) g 1g g 2g 2g 1g g 2g with the two configurations coupled by the spin-orbit interaction. The 3Eg(b) and 3B2g states have easy-axis and easy-plane anisotropies, respectively. Our model accounts for an easy-plane magnetic anisotropy and the measured magnitudes of the in-plane orbital and spin moments. The proximity in energy of the two configurations allows a switching of the magnetic anisotropy from easy plane to easy axis with a small change in the crystal field, as recently observed for FePc adsorbed on an oxidized Cu surface. We also discuss the possibility of a quintet ground state (5A1g is 250 meV above the ground state) with planar anisotropy by manipulation of the Fe-C bond length by depositing the complex on a substrate that is subjected to a mechanical strain.
Charged oscillator quantum state generation with Rydberg atoms
Stevenson, Robin; Hofferberth, Sebastian; Lesanovsky, Igor
2016-01-01
We explore the possibility of engineering quantum states of a charged mechanical oscillator by coupling it to a stream of atoms in superpositions of high-lying Rydberg states. Our scheme relies on the driving of a two-phonon resonance within the oscillator by coupling it to an atomic two-photon transition. This approach effectuates a controllable open system dynamics on the oscillator that permits the creation of squeezed and other non-classical states. We show that these features are robust to thermal noise arising from a coupling of the oscillator with the environment. The possibility to create non-trivial quantum states of mechanical systems, provided by the proposed setup, is central to applications such as sensing and metrology and moreover allows the exploration of fundamental questions concerning the boundary between classical and quantum mechanical descriptions of macroscopic objects.
Phenomenological description of ground state bands for doubly even plutonium-isotopes
Alsoraya, A M
2002-01-01
The energy levels of the ground state bands of even-even plutonium-isotopes are studied according to the variable moment of inertia (VMI), variable moment of inertia nuclear softness (VMINS) and nuclear softness (NS) models. In general, the NS3 model leads to more reasonable results than the others. The backbending phenomena in these were described and discussed. The calculations of the transition probabilities B(E2) show that the effect of addition of each neutron pair on the deformation parameter (BETA) is very small. Furthermore, the proton and neutron effective charges are found to be e sub = 0.48 eb and e-v =0.33 eb.
The ground state of the D=11 supermembrane and matrix models on compact regions
Boulton, L; Restuccia, A
2015-01-01
We establish a general framework for the analysis of boundary value problems at zero energy of matrix models on compact regions. This allows us to prove existence and uniqueness of ground state wavefunctions for the mass operator of the D=11 regularized supermembrane theory (and therefore the N=16 supersymmetric matrix model) on a ball of finite radius. Our results rely on the structure of the associated Dirichlet form and a factorization in terms of the supersymmetric charges. They also rely on the polynomial structure of the potential and various other supersymmetric properties of the system.
Ground State Correlations Using exp(S) Method for the ^16O Nucleus.
Mihaila, Bogdan; Heisenberg, Jochen
1998-04-01
We use the Argonne-v18 potential together with a phenomenological three-nucleon interaction to do the calculation of the mean-field single particle wave functions and the correlation operator describing the ground state of the ^16O nucleus. Our correlation operator includes the contributions from up to 4p4h terms. We present a breakdown of the contributions to the binding from the two- and the three-body interactions. The one- and the two-body densities for ^16O are presented. Effects of the center-of-mass correction on the charge density and form factor are also discussed.
The ground state of the D = 11 supermembrane and matrix models on compact regions
Boulton, Lyonell; Garcia del Moral, Maria Pilar; Restuccia, Alvaro
2016-09-01
We establish a general framework for the analysis of boundary value problems of matrix models at zero energy on compact regions. We derive existence and uniqueness of ground state wavefunctions for the mass operator of the D = 11 regularized supermembrane theory, that is the N = 16 supersymmetric SU (N) matrix model, on balls of finite radius. Our results rely on the structure of the associated Dirichlet form and a factorization in terms of the supersymmetric charges. They also rely on the polynomial structure of the potential and various other supersymmetric properties of the system.
Charge state breeding experiences and plans at TRIUMF
Ames, F., E-mail: ames@triumf.ca; Marchetto, M.; Mjøs, A.; Morton, A. C. [TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T2A3 (Canada)
2016-02-15
At the Isotope Separation and ACceleration (ISAC) facility at TRIUMF, an electron cyclotron resonance ion source (ECRIS) has been set up for the charge state breeding of radioactive ions. In order to reduce background from stable ions generated in the ECRIS, several measures, including changing materials for the plasma chamber and the surrounding components, have been implemented. Further reduction has been achieved by using the post-accelerator chain as a mass filter. Since the implementation of those measures in 2013, physics experiments with accelerated radioactive isotopes of Rb, Sr, K, and Mg have been performed. In most cases, a charge breeding efficiency of several percent has been achieved. With the planned expansion of the isotope production capabilities at TRIUMF within the Advanced Rare IsotopE Laboratory project, two new target stations, one using photo-fission induced by a high-power electron beam at 50 MeV and the other one using 480 MeV protons as at ISAC, will be put into operation within the next 5 yr. Additionally, a new electron beam ion source (EBIS) based charge state breeding system will be installed. Background from such a source is expected to be much lower. The drawback is that for the efficient operation of such a system, pulsed beam operation is required, which makes the installation of an additional ion buncher in front of the EBIS necessary.
Sowinski, Andrew; Mayne, Antonio; Javed, Bassam; Mehrani, Poupak, E-mail: poupak.mehrani@uottawa.ca [University of Ottawa, Chemical and Biological Engineering Department, 161 Louis Pasteur St., Ottawa, Ontario, K1N 6N5 (Canada)
2011-06-23
In gas-solid fluidized beds as particles are fluidized, they continuously come into contact with other particles, as well as the fluidization column wall. This generates electrostatic charges by means of triboelectrification and frictional charging, leading to particle agglomeration, reactor wall fouling, and eventually process downtime and large financial losses. Grounding the fluidization column has been considered as a means of helping electrostatic charge dissipation within fluidized beds; however, in industrial applications despite the process vessels being grounded, the electrostatic problem still persists. This work focused on the effect of fluidization column grounding on particle wall fouling. Experiments were conducted in an atmospheric system consist of a 0.1 m in diameter carbon steel fluidization column. The mass and charge-to-mass ratio (q/m) of the particles that remained adhered to the column wall upon the completion of one hour fluidization period were measured in an electrically isolated and grounded columns to quantitatively determine the amount of reactor wall fouling. Polyethylene particles with different particle size ranges (300- 1000 {mu}m) were fluidized with extra dry air at 1.5 times their respective minimum fluidization velocity (u{sub mf}). Results obtained in the grounded fluidization column were not significantly different from those in the isolated column for all particle size ranges tested where the particles mass collected and q/m and were found to be generally similar.
MULTIPLY CHARGED IONS COLLISIONS WITH ATOMS INTO EXCITED STATES
PanGuangyan
1990-01-01
The emission spectra in collisions between Ions and Atoms have been measured by an Optical Multichannel Analysis System (OMA).The experimental results demonstrate that there are two channels of excitation in collision between single charged ions and atoms and three channels of excitation in collision between double charged ions and atoms.Emission cross cestions and excitation cross sections have been obtained.K.Kadota et al and R.Shingal et al suggested that,under the appropriate conditions,the H42+-Li and He2++Na collision systems can be used efficiently to produce a laser of Lyman-α(30,4nm) and Lyman-β(25.6nm)lines via cascade to He+(2P)state.
Simulation of the hydrogen ground state in stochastic electrodynamics
Nieuwenhuizen, Theo M.; Liska, Matthew T. P.
2015-10-01
Stochastic electrodynamics is a classical theory which assumes that the physical vacuum consists of classical stochastic fields with average energy \\frac{1}{2}{{\\hslash }}ω in each mode, i.e., the zero-point Planck spectrum. While this classical theory explains many quantum phenomena related to harmonic oscillator problems, hard results on nonlinear systems are still lacking. In this work the hydrogen ground state is studied by numerically solving the Abraham-Lorentz equation in the dipole approximation. First the stochastic Gaussian field is represented by a sum over Gaussian frequency components, next the dynamics is solved numerically using OpenCL. The approach improves on work by Cole and Zou 2003 by treating the full 3d problem and reaching longer simulation times. The results are compared with a conjecture for the ground state phase space density. Though short time results suggest a trend towards confirmation, in all attempted modellings the atom ionises at longer times.
Ground-State Phase Diagram of S = 1 Diamond Chains
Hida, Kazuo; Takano, Ken'ichi
2017-03-01
We investigate the ground-state phase diagram of a spin-1 diamond chain. Owing to a series of conservation laws, any eigenstate of this system can be expressed using the eigenstates of finite odd-length chains or infinite chains with spins 1 and 2. The ground state undergoes quantum phase transitions with varying λ, a parameter that controls frustration. Exact upper and lower bounds for the phase boundaries between these phases are obtained. The phase boundaries are determined numerically in the region not explored in a previous work [Takano et al., https://doi.org/10.1088/0953-8984/8/35/009" xlink:type="simple">J. Phys.: Condens. Matter 8, 6405 (1996)].
Cluster expansion for ground states of local Hamiltonians
Bastianello, Alvise; Sotiriadis, Spyros
2016-08-01
A central problem in many-body quantum physics is the determination of the ground state of a thermodynamically large physical system. We construct a cluster expansion for ground states of local Hamiltonians, which naturally incorporates physical requirements inherited by locality as conditions on its cluster amplitudes. Applying a diagrammatic technique we derive the relation of these amplitudes to thermodynamic quantities and local observables. Moreover we derive a set of functional equations that determine the cluster amplitudes for a general Hamiltonian, verify the consistency with perturbation theory and discuss non-perturbative approaches. Lastly we verify the persistence of locality features of the cluster expansion under unitary evolution with a local Hamiltonian and provide applications to out-of-equilibrium problems: a simplified proof of equilibration to the GGE and a cumulant expansion for the statistics of work, for an interacting-to-free quantum quench.
Ground-state structures of atomic metallic hydrogen.
McMahon, Jeffrey M; Ceperley, David M
2011-04-22
Ab initio random structure searching using density functional theory is used to determine the ground-state structures of atomic metallic hydrogen from 500 GPa to 5 TPa. Including proton zero-point motion within the harmonic approximation, we estimate that molecular hydrogen dissociates into a monatomic body-centered tetragonal structure near 500 GPa (r(s)=1.23) that remains stable to 1 TPa (r(s)=1.11). At higher pressures, hydrogen stabilizes in an …ABCABC… planar structure that is similar to the ground state of lithium, but with a different stacking sequence. With increasing pressure, this structure compresses to the face-centered cubic lattice near 3.5 TPa (r(s)=0.92).
Ground-state rotational constants of 12CH 3D
Chackerian, C.; Guelachvili, G.
1980-12-01
An analysis of ground-state combination differences in the ν2( A1) fundamental band of 12CH 3D ( ν0 = 2200.03896 cm -1) has been made to yield values for the rotational constants B0, D0J, D0JK, H0JJJ, H0JJK, H0JKK, LJJJJ, L0JJJK, and order of magnitude values for L0JJKK and L0JKKK. These constants should be useful in assisting radio searches for this molecule in astrophysical sources. In addition, splittings of A1A2 levels ( J ≥ 17, K = 3) have been measured in both the ground and excited vibrational states of this band.
Non-uniform ground state for the Bose gas
2000-01-01
We study the ground state, sum a_X |X>, of N hard-core bosons on a finite lattice in configuration space, X={x_1,...,x_N}. All a_X being positive, the ratios a_X / sum a_Y can be interpreted as probabilities P_a (X). Let E denote the energy of the ground state and B_X the number of nearest-neighbor particle-hole pairs in the configuration X. We prove the concentration of P_a to X's with B_X in a sqrt(|E|)-neighborhood of |E|, show that the average of a_X over configurations with B_X=n increas...
Cluster expansion for ground states of local Hamiltonians
Alvise Bastianello
2016-08-01
Full Text Available A central problem in many-body quantum physics is the determination of the ground state of a thermodynamically large physical system. We construct a cluster expansion for ground states of local Hamiltonians, which naturally incorporates physical requirements inherited by locality as conditions on its cluster amplitudes. Applying a diagrammatic technique we derive the relation of these amplitudes to thermodynamic quantities and local observables. Moreover we derive a set of functional equations that determine the cluster amplitudes for a general Hamiltonian, verify the consistency with perturbation theory and discuss non-perturbative approaches. Lastly we verify the persistence of locality features of the cluster expansion under unitary evolution with a local Hamiltonian and provide applications to out-of-equilibrium problems: a simplified proof of equilibration to the GGE and a cumulant expansion for the statistics of work, for an interacting-to-free quantum quench.
The ground state in a spin-one color superconductor
Schmitt, A
2004-01-01
Color superconductors in which quarks of the same flavor form Cooper pairs are investigated. These Cooper pairs carry total spin one. A systematic group-theoretical classification of possible phases in a spin-one color superconductor is presented, revealing parallels and differences to the theory of superfluid $^3$He. General expressions for the gap parameter, the critical temperature, and the pressure are derived and evaluated for several spin-one phases, with special emphasis on the angular structure of the gap equation. It is shown that, in a spin-one color superconductor, the (transverse) A phase is expected to be the ground state. This is in contrast to $^3$He, where the ground state is in the B phase.
EIT ground-state cooling of long ion strings
Lechner, R; Hempel, C; Jurcevic, P; Lanyon, B P; Monz, T; Brownnutt, M; Blatt, R; Roos, C F
2016-01-01
Electromagnetically-induced-transparency (EIT) cooling is a ground-state cooling technique for trapped particles. EIT offers a broader cooling range in frequency space compared to more established methods. In this work, we experimentally investigate EIT cooling in strings of trapped atomic ions. In strings of up to 18 ions, we demonstrate simultaneous ground state cooling of all radial modes in under 1 ms. This is a particularly important capability in view of emerging quantum simulation experiments with large numbers of trapped ions. Our analysis of the EIT cooling dynamics is based on a novel technique enabling single-shot measurements of phonon numbers, by rapid adiabatic passage on a vibrational sideband of a narrow transition.
Cluster expansion for ground states of local Hamiltonians
Bastianello, Alvise, E-mail: abastia@sissa.it [SISSA, via Bonomea 265, 34136 Trieste (Italy); INFN, Sezione di Trieste (Italy); Sotiriadis, Spyros [SISSA, via Bonomea 265, 34136 Trieste (Italy); INFN, Sezione di Trieste (Italy); Institut de Mathématiques de Marseille (I2M), Aix Marseille Université, CNRS, Centrale Marseille, UMR 7373, 39, rue F. Joliot Curie, 13453, Marseille (France); University of Roma Tre, Department of Mathematics and Physics, L.go S.L. Murialdo 1, 00146 Roma (Italy)
2016-08-15
A central problem in many-body quantum physics is the determination of the ground state of a thermodynamically large physical system. We construct a cluster expansion for ground states of local Hamiltonians, which naturally incorporates physical requirements inherited by locality as conditions on its cluster amplitudes. Applying a diagrammatic technique we derive the relation of these amplitudes to thermodynamic quantities and local observables. Moreover we derive a set of functional equations that determine the cluster amplitudes for a general Hamiltonian, verify the consistency with perturbation theory and discuss non-perturbative approaches. Lastly we verify the persistence of locality features of the cluster expansion under unitary evolution with a local Hamiltonian and provide applications to out-of-equilibrium problems: a simplified proof of equilibration to the GGE and a cumulant expansion for the statistics of work, for an interacting-to-free quantum quench.
Room temperature skyrmion ground state stabilized through interlayer exchange coupling
Chen, Gong, E-mail: gchenncem@gmail.com; Schmid, Andreas K. [NCEM, Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Mascaraque, Arantzazu [Depto. Física de Materiales, Universidad Complutense de Madrid, 28040 Madrid (Spain); Unidad Asociada IQFR (CSIC) - UCM, 28040 Madrid (Spain); N' Diaye, Alpha T. [Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)
2015-06-15
Possible magnetic skyrmion device applications motivate the search for structures that extend the stability of skyrmion spin textures to ambient temperature. Here, we demonstrate an experimental approach to stabilize a room temperature skyrmion ground state in chiral magnetic films via exchange coupling across non-magnetic spacer layers. Using spin polarized low-energy electron microscopy to measure all three Cartesian components of the magnetization vector, we image the spin textures in Fe/Ni films. We show how tuning the thickness of a copper spacer layer between chiral Fe/Ni films and perpendicularly magnetized Ni layers permits stabilization of a chiral stripe phase, a skyrmion phase, and a single domain phase. This strategy to stabilize skyrmion ground states can be extended to other magnetic thin film systems and may be useful for designing skyrmion based spintronics devices.
Terahertz spectroscopy of ground state HD18O
Yu, Shanshan; Pearson, John C.; Drouin, Brian J.; Miller, Charles E.; Kobayashi, Kaori; Matsushima, Fusakazu
2016-10-01
Terahertz absorption spectroscopy was employed to measure the ground state pure rotational transitions of the water isotopologue HD18O . A total of 105 pure rotational transitions were observed in the 0.5-5.0 THz region with ∼ 100 kHz accuracy for the first time. The observed positions were fit to experimental accuracy using the Euler series expansion of the asymmetric-top Hamiltonian together with the literature Microwave, Far-IR and IR data in the ground state and ν2 . The new measurements and predictions reported here support the analysis of astronomical observations by high-resolution spectroscopic telescopes such as SOFIA and ALMA where laboratory rest frequencies with uncertainties of 1 MHz or less are required for proper analysis of velocity resolved astrophysical data.
Ground state solutions for non-local fractional Schrodinger equations
Yang Pu
2015-08-01
Full Text Available In this article, we study a time-independent fractional Schrodinger equation with non-local (regional diffusion $$ (-\\Delta^{\\alpha}_{\\rho}u + V(xu = f(x,u \\quad \\text{in }\\mathbb{R}^{N}, $$ where $\\alpha \\in (0,1$, $N > 2\\alpha$. We establish the existence of a non-negative ground state solution by variational methods.
0{sup +} ground state dominance in many-body systems
Zhao, Yu-Min [Southeast Univ., Dept. of Physics, Nanjing (China); Arima, Akito [The House of Councilors, Tokyo (Japan); Yoshinaga, Naotaka [Saitama Univ., Physics Dept., Saitama (Japan)
2002-12-01
We propose a simple approach to predict the angular momentum I ground states (Ig.s.) probabilities of many-body systems without diagonalization of the hamiltonian using random interactions. It is suggested that the 0g.s. dominance in boson systems and even valence nucleon systems is not given by the model space as previously assumed, but by specific two-body interactions. (author)
Detecting topological order in a ground state wave function
2005-01-01
A large class of topological orders can be understood and classified using the string-net condensation picture. These topological orders can be characterized by a set of data (N, d_i, F^{ijk}_{lmn}, \\delta_{ijk}). We describe a way to detect this kind of topological order using only the ground state wave function. The method involves computing a quantity called the ``topological entropy'' which directly measures the quantum dimension D = \\sum_i d^2_i.
Reduced M(atrix) theory models: ground state solutions
López, J L
2015-01-01
We propose a method to find exact ground state solutions to reduced models of the SU($N$) invariant matrix model arising from the quantization of the 11-dimensional supermembrane action in the light-cone gauge. We illustrate the method by applying it to lower dimensional toy models and for the SU(2) group. This approach could, in principle, be used to find ground state solutions to the complete 9-dimensional model and for any SU($N$) group. The Hamiltonian, the supercharges and the constraints related to the SU($2$) symmetry are built from operators that generate a multicomponent spinorial wave function. The procedure is based on representing the fermionic degrees of freedom by means of Dirac-like gamma matrices, as was already done in the first proposal of supersymmetric (SUSY) quantum cosmology. We exhibit a relation between these finite $N$ matrix theory ground state solutions and SUSY quantum cosmology wave functions giving a possible physical significance of the theory even for finite $N$.
Alternative ground states enable pathway switching in biological electron transfer
Abriata, Luciano A.; Álvarez-Paggi, Damián; Ledesma, Gabriela N.; Blackburn, Ninian J.; Vila, Alejandro J.; Murgida, Daniel H.
2012-01-01
Electron transfer is the simplest chemical reaction and constitutes the basis of a large variety of biological processes, such as photosynthesis and cellular respiration. Nature has evolved specific proteins and cofactors for these functions. The mechanisms optimizing biological electron transfer have been matter of intense debate, such as the role of the protein milieu between donor and acceptor sites. Here we propose a mechanism regulating long-range electron transfer in proteins. Specifically, we report a spectroscopic, electrochemical, and theoretical study on WT and single-mutant CuA redox centers from Thermus thermophilus, which shows that thermal fluctuations may populate two alternative ground-state electronic wave functions optimized for electron entry and exit, respectively, through two different and nearly perpendicular pathways. These findings suggest a unique role for alternative or “invisible” electronic ground states in directional electron transfer. Moreover, it is shown that this energy gap and, therefore, the equilibrium between ground states can be fine-tuned by minor perturbations, suggesting alternative ways through which protein–protein interactions and membrane potential may optimize and regulate electron–proton energy transduction. PMID:23054836
Nuclear ground-state masses and deformations: FRDM(2012)
Moller, P; Ichikawa, T; Sagawa, H
2015-01-01
We tabulate the atomic mass excesses and binding energies, ground-state shell-plus-pairing corrections, ground-state microscopic corrections, and nuclear ground-state deformations of 9318 nuclei ranging from $^{16}$O to $A=339$. The calculations are based on the finite-range droplet macroscopic model and the folded-Yukawa single-particle microscopic model. Relative to our FRDM(1992) mass table in {\\sc Atomic Data and Nuclear Data Tables} [{\\bf 59} 185 (1995)], the results are obtained in the same model, but with considerably improved treatment of deformation and fewer of the approximations that were necessary earlier, due to limitations in computer power. The more accurate execution of the model and the more extensive and more accurate experimental mass data base now available allows us to determine one additional macroscopic-model parameter, the density-symmetry coefficient $L$, which was not varied in the previous calculation, but set to zero. Because we now realize that the FRDM is inaccurate for some high...
Coupled cluster calculations of ground and excited states of nuclei
Kowalski, K L; Hjorth-Jensen, M; Papenbrock, T; Piecuch, P
2004-01-01
The standard and renormalized coupled cluster methods with singles, doubles, and noniterative triples and their generalizations to excited states, based on the equation of motion coupled cluster approach, are applied to the He-4 and O-16 nuclei. A comparison of coupled cluster results with the results of the exact diagonalization of the Hamiltonian in the same model space shows that the quantum chemistry inspired coupled cluster approximations provide an excellent description of ground and excited states of nuclei. The bulk of the correlation effects is obtained at the coupled cluster singles and doubles level. Triples, treated noniteratively, provide the virtually exact description.
Lakshmi, L Seetha [XS and CGS, Materials Science Division, Indira Gandhi Centre For Atomic Research, Kalpakkam, Tamil Nadu 603102 (India); Doerr, K [Institute of Metallic Materials, IFW Dresden, Postach 270116, Dresden 01171 (Germany); Nenkov, K [Institute of Metallic Materials, IFW Dresden, Postach 270116, Dresden 01171 (Germany); Sastry, V S [XS and CGS, Materials Science Division, Indira Gandhi Centre For Atomic Research, Kalpakkam, Tamil Nadu 603102 (India); Mueller, K-H [Institute of Metallic Materials, IFW Dresden, Postach 270116, Dresden 01171 (Germany)
2007-06-13
The effect of charge state modification at the Mn site on the physical properties of CMR manganites is reported. With a view to avoiding additional complexity of local spin coupling effects, Mn site substitution of La{sub 0.67}Ca{sub 0.33}MnO{sub 3} is carried out with appropriate diamagnetic ions-Zn{sup 2+}, Zr{sup 4+}, Ta{sup 5+} and W{sup 6+}-of different valence states. The substitution results in size changes of the unit cell and enhanced local structural distortions, which increase in the order Zn, Zr, Ta and W. The ground state is ferromagnetic-metallic below a certain critical concentration x{sub c} of the substituents, beyond which the magnetic ground state shows a glassy behaviour. The phase transition temperatures (T{sub MI} and T{sub c}) decrease with substitution, but to different extents. The observed suppression rates of the Curie temperature, T{sub c}, of {approx}39 K/at.% and {approx}45 K/at.% respectively for Ta{sup 5+} and W{sup 6+} substituted compounds are the highest reported in the Mn site substituted CMR manganites. Besides the modification of majority carrier concentration due to the increased (decreased) Mn{sup 3+} concentration and enhanced local structural effects, the local electrostatic potential of the substituents seems to contribute to the unusually strong reduction in the itinerant ferromagnetism and the observed glassy states.
Ground states of fermionic lattice Hamiltonians with permutation symmetry
Kraus, Christina V.; Lewenstein, Maciej; Cirac, J. Ignacio
2013-08-01
We study the ground states of lattice Hamiltonians that are invariant under permutations, in the limit where the number of lattice sites N→∞. For spin systems, these are product states, a fact that follows directly from the quantum de Finetti theorem. For fermionic systems, however, the problem is very different, since mode operators acting on different sites do not commute, but anticommute. We construct a family of fermionic states, F, from which such ground states can be easily computed. They are characterized by few parameters whose number only depends on M, the number of modes per lattice site. We also give an explicit construction for M=1,2. In the first case, F is contained in the set of Gaussian states, whereas in the second it is not. Inspired by that construction, we build a set of fermionic variational wave functions, and apply it to the Fermi-Hubbard model in two spatial dimensions, obtaining results that go beyond the generalized Hartree-Fock theory.
Ground state energies from converging and diverging power series expansions
Lisowski, C.; Norris, S.; Pelphrey, R.; Stefanovich, E.; Su, Q.; Grobe, R.
2016-10-01
It is often assumed that bound states of quantum mechanical systems are intrinsically non-perturbative in nature and therefore any power series expansion methods should be inapplicable to predict the energies for attractive potentials. However, if the spatial domain of the Schrödinger Hamiltonian for attractive one-dimensional potentials is confined to a finite length L, the usual Rayleigh-Schrödinger perturbation theory can converge rapidly and is perfectly accurate in the weak-binding region where the ground state's spatial extension is comparable to L. Once the binding strength is so strong that the ground state's extension is less than L, the power expansion becomes divergent, consistent with the expectation that bound states are non-perturbative. However, we propose a new truncated Borel-like summation technique that can recover the bound state energy from the diverging sum. We also show that perturbation theory becomes divergent in the vicinity of an avoided-level crossing. Here the same numerical summation technique can be applied to reproduce the energies from the diverging perturbative sums.
Local solid-state modification of nanopore surface charges
Kox, Ronald; Chen, Chang; Arjmandi, Nima; Lagae, Liesbet; Borghs, Gustaaf; 10.1088/0957-4484/21/33/335703
2012-01-01
The last decade, nanopores have emerged as a new and interesting tool for the study of biological macromolecules like proteins and DNA. While biological pores, especially alpha-hemolysin, have been promising for the detection of DNA, their poor chemical stability limits their use. For this reason, researchers are trying to mimic their behaviour using more stable, solid-state nanopores. The most successful tools to fabricate such nanopores use high energy electron or ions beams to drill or reshape holes in very thin membranes. While the resolution of these methods can be very good, they require tools that are not commonly available and tend to damage and charge the nanopore surface. In this work, we show nanopores that have been fabricated using standard micromachning techniques together with EBID, and present a simple model that is used to estimate the surface charge. The results show that EBID with a silicon oxide precursor can be used to tune the nanopore surface and that the surface charge is stable over a...
High-Intensity, High Charge-State Heavy Ion Sources
Alessi, J
2004-01-01
There are many accelerator applications for high intensity heavy ion sources, with recent needs including dc beams for RIA, and pulsed beams for injection into synchrotrons such as RHIC and LHC. The present status of sources producing high currents of high charge state heavy ions will be reviewed. These sources include ECR, EBIS, and Laser ion sources. The benefits and limitations for these type sources will be described, for both dc and pulsed applications. Possible future improvements in these type sources will also be discussed.
Gold, A.; Ghazali, A.
1996-09-01
In the low-density regime bound states between negative (repulsive) test charges are obtained when many-body effects (exchange and correlation) are incorporated in the screening function of the three-dimensional electron gas via the local-field correction. The Schrödinger equation is solved in the momentum space by diagonalizing the corresponding matrix. We also perform variational calculations and find good agreement between the two methods. For high electron density 0953-8984/8/40/006/img5 (0953-8984/8/40/006/img6 is the density parameter) no bound states are found. Below a critical density 0953-8984/8/40/006/img7 the number and the energy of bound states increase with decreasing electron density. For large 0953-8984/8/40/006/img6 the binding energy for the ground state saturates near 0953-8984/8/40/006/img9. We discuss the wave functions of the ground state and of the lowest excited states. We also present results for the effects of exchange and correlation for a positive (attractive) test charge and we discuss results for the ground state and excited states.
Identifying interfacial charge transfer states in organic heterostructures (Conference Presentation)
Arndt, Andreas P.; Gerhard, Marina; Howard, Ian A.; Koch, Martin; Lemmer, Ulrich
2016-09-01
Charge transfer (CT) states play evidently an important role at the interface of organic heterostructures but their identification and characterization is often experimentally less obvious and challenging. We studied two exemplary material systems which both represented a benchmark within the research of organic photovoltaics at their time: the homopolymer P3HT blended with PC61BM and the copolymer PTB7 blended with PC71BM. In both heterostructures, we could identify a distinct CT state emission by the use of NIR time-resolved photoluminescence (PL) [1], [2]. The selectivity of this technique enables us to clearly probe the energetics and dynamics of weak emitting interfacial states and therefore to prove differences in the CT state characteristics between the two systems. We went beyond this previous work and investigated the time and temperature dependent emission anisotropy as well as the electric field dependence of the time-resolved PL for both blends and the pristine polymers, respectively. In both cases the CT state emission clearly deviates from the one of the primarily excited singlet excitons: the emission anisotropy reveals an additional relaxation pathway for the exciton which is connected with a change of the transition dipole moment of the emission, and under applied bias different quenching thresholds can give access to varying binding energies of the emissive excitons involved. Finally, we think that our findings demonstrate how interfacial CT state emission can be clearly identified as such and how it can be unambiguously distinguished from singlet exciton emission.
Continuous Vibrational Cooling of Ground State Rb2
Tallant, Jonathan; Marcassa, Luis
2014-05-01
The process of photoassociation generally results in a distribution of vibrational levels in the electronic ground state that is energetically close to the dissociation limit. Several schemes have appeared that aim to transfer the population from the higher vibrational levels to lower ones, especially the ground vibrational state. We demonstrate continuous production of vibrationally cooled Rb2 using optical pumping. The vibrationally cooled molecules are produced in three steps. First, we use a dedicated photoassociation laser to produce molecules in high vibrational levels of the X1Σg+ state. Second, a broadband fiber laser at 1071 nm is used to transfer the molecules to lower vibrational levels via optical pumping through the A1Σu+ state. This process transfers the molecules from vibrational levels around ν ~= 113 to a distribution of levels where ν superluminescent diode near 685 nm that has its frequency spectrum shaped. The resulting vibrational distributions are probed using resonance-enhanced multiphoton ionization with a pulsed dye laser near 670 nm. The results are presented and compared with theoretical simulations. This work was supported by Fapesp and INCT-IQ.
Nuclear Ground State Properties in Strontium by Fast Beam Laser Spectroscopy
2002-01-01
Hyperfine structures and isotope shifts of strontium isotopes with A=78 to A=100 were measured by collinear fast beam laser spectroscopy. Nuclear spins, moments and changes in mean square charge radii are extracted from the data. The spins and moments of most of the odd isotopes are explained in the framework of the single particle model. The changes in mean square charge radii show a decrease with increasing neutron number below the N=50 shell closure. Above N=50 the charge radii increase regularly up to N=59 before revealing a strong discontinuity, indicating the onset of strong ground state deformation. A comparison of the droplet model shows that for the transitional isotopes below and above N=50, the zero point quadrupole motion describes part of the observed shell effect. Calculations carried out in the Hartree-Fock plus BCS model suggest an additional change in the surface region of the charge distribution at spherical shape. From these calculations it is furthermore proposed, that the isotopes $^7
The B850/B875 Photosynthetic Complex Ground and Excited State are Both Coherent
Squire, R H; Rubio, A; Ingles, J R; Cunningham, W A
2016-01-01
A bacterial photosynthetic light harvesting complex PLHC absorbs a photon and transfers this energy almost perfectly at room temperature RT to a Reaction Center RC, where charge separation occurs. While there are a number of possible light absorbers involved in this process, our focus is the B850 and B875 complexes. We propose that the dominant feature of the ground states in the B850 ring and the B875 open chain are pseudo one dimensional metals due to each bacteriochlorophyll a BChl containing a coordinated magnesium ion Mg2+. The Mg ion structure undergoes a static Peierls distortion that results in symmetry breaking that changes the even spacing of the Mg/BChl molecules comprising the chains to the experimentally observed Mg/BChl dimers. The results are charge density waves CDW, one for each type of the two complexes that result in an energy gap in the single particle electronic spectrum and coherent phonon s spanning the entire rings. The ground state CDWs seem to have two functions the first is to form ...
Estimating the ground-state probability of a quantum simulation with product-state measurements
Bryce eYoshimura
2015-10-01
Full Text Available .One of the goals in quantum simulation is to adiabatically generate the ground state of a complicated Hamiltonian by starting with the ground state of a simple Hamiltonian and slowly evolving the system to the complicated one. If the evolution is adiabatic and the initial and final ground states are connected due to having the same symmetry, then the simulation will be successful. But in most experiments, adiabatic simulation is not possible because it would take too long, and the system has some level of diabatic excitation. In this work, we quantify the extent of the diabatic excitation even if we do not know {it a priori} what the complicated ground state is. Since many quantum simulator platforms, like trapped ions, can measure the probabilities to be in a product state, we describe techniques that can employ these simple measurements to estimate the probability of being in the ground state of the system after the diabatic evolution. These techniques do not require one to know any properties about the Hamiltonian itself, nor to calculate its eigenstate properties. All the information is derived by analyzing the product-state measurements as functions of time.
Support vector based battery state of charge estimator
Hansen, Terry; Wang, Chia-Jiu
This paper investigates the use of a support vector machine (SVM) to estimate the state-of-charge (SOC) of a large-scale lithium-ion-polymer (LiP) battery pack. The SOC of a battery cannot be measured directly and must be estimated from measurable battery parameters such as current and voltage. The coulomb counting SOC estimator has been used in many applications but it has many drawbacks [S. Piller, M. Perrin, Methods for state-of-charge determination and their application, J. Power Sources 96 (2001) 113-120]. The proposed SVM based solution not only removes the drawbacks of the coulomb counting SOC estimator but also produces accurate SOC estimates, using industry standard US06 [V.H. Johnson, A.A. Pesaran, T. Sack, Temperature-dependent battery models for high-power lithium-ion batteries, in: Presented at the 17th Annual Electric Vehicle Symposium Montreal, Canada, October 15-18, 2000. The paper is downloadable at website http://www.nrel.gov/docs/fy01osti/28716.pdf] aggressive driving cycle test procedures. The proposed SOC estimator extracts support vectors from a battery operation history then uses only these support vectors to estimate SOC, resulting in minimal computation load and suitable for real-time embedded system applications.
Charge States of Krypton and Xenon in the Solar Wind
Bochsler, Peter; Fludra, Andrzej; Giunta, Alessandra
2017-09-01
We calculate charge state distributions of Kr and Xe in a model for two different types of solar wind using the effective ionization and recombination rates provided from the OPEN_ADAS data base. The charge states of heavy elements in the solar wind are essential for estimating the efficiency of Coulomb drag in the inner corona. We find that xenon ions experience particularly low Coulomb drag from protons in the inner corona, comparable to the notoriously weak drag of protons on helium ions. It has been found long ago that helium in the solar wind can be strongly depleted near interplanetary current sheets, whereas coronal mass ejecta are sometimes strongly enriched in helium. We argue that if the extraordinary variability of the helium abundance in the solar wind is due to inefficient Coulomb drag, the xenon abundance must vary strongly. In fact, a secular decrease of the solar wind xenon abundance relative to the other heavier noble gases (Ne, Ar, Kr) has been postulated based on a comparison of noble gases in recently irradiated and ancient samples of ilmenite in the lunar regolith. We conclude that decreasing solar activity and decreasing frequency of coronal mass ejections over the solar lifetime might be responsible for a secularly decreasing abundance of xenon in the solar wind.
Coulomb charging energy of vacancy-induced states in graphene
Miranda, V. G.; Dias da Silva, Luis G. G. V.; Lewenkopf, C. H.
2016-08-01
Vacancies in graphene have been proposed to give rise to π -like magnetism in carbon materials, a conjecture which has been supported by recent experimental evidence. A key element in this "vacancy magnetism" is the formation of magnetic moments in vacancy-induced electronic states. In this work we compute the charging energy U of a single-vacancy-generated localized state for bulk graphene and graphene ribbons. We use a tight-binding model to calculate the dependency of the charging energy U on the amplitudes of the localized wave function on the graphene lattice sites. We show that for bulk graphene U scales with the system size L as (lnL) -2, confirming the predictions in the literature, based on heuristic arguments. In contrast, we find that for realistic system sizes U is of the order of eV, a value that is orders of magnitude higher than the previously reported estimates. Finally, when edges are considered, we show that U is very sensitive to the vacancy position with respect to the graphene flake boundaries. In the case of armchair nanoribbons, we find a strong enhancement of U in certain vacancy positions as compared to the value for vacancies in bulk graphene.
The charge state of iron implanted into sapphire
McHargue, C.J.; Sklad, P.S.; White, C.W.; Farlow, G.C.; Perez, A.; Kornilios, N.; Marest, G.
1987-08-01
Several techniques (RBS, TEM, CEMS) have been used to characterize sapphire single crystals implanted with iron at room temperature to fluences of 10/sup 16/ to 10/sup 17/ ions cm/sup -2/. At low fluences the as-implanted iron is found mainly in the ferrous state. As the fluence is increased, Fe/sup 3 +/ and metallic iron clusters became dominant. There is a strong correlation between the probability of finding specific configurations of iron ions within four cation coordination shells and the relative amounts of each charge state observed. The superparamagnetic behavior of the clusters suggest that they are of the order of 2 nm in size but the large amount of irradiation-induced damage and residual stress has prevented their imaging by TEM. 13 refs., 7 figs.
Analysis of Ion Charge States in Solar Wind and CMEs
Arati Dasgupta; J. M. Laming
2008-03-01
We discuss needs in dielectronic recombination data motivated by recent work directed at a quantitative understanding of ion charge states of various elements observed in situ in the solar wind and CMEs. The competing processes of ionization and recombination lead to departures from collision ionization equilibrium. The use of this as a diagnostic of acceleration and heating processes of the solar wind and CMEs is sensitive to the accuracy of the atomic rates in a way that steady state ionization equilibrium plasmas are not. The most pressing need is dielectronic recombination rates for ions Fe8+-12+. These are among the dominant species observed in various regions of the solar wind and CMEs, and in remotely sensed EUV spectra.
Application of Genetic Neural Network in Power Battery Charging State-of-Charge Estimation
Yongqin Zhou
2011-03-01
Full Text Available With global non-renewable resources and environmental issues becoming more apparent, the development of new energy vehicles have become the trend of auto industry. Hybrid vehicle becomes the key development of new energy vehicles with its long distance, low pollution, low fuel consumption characteristics and so on. The battery performances directly influence the quality of the whole vehicle performance. Considering the importance of the battery state of charge (SOC estimation and the nonlinear relationship between the battery SOC and the external characteristic, genetic algorithm (GA and back propagation (BP neural network are proposed. Because of the strong global search capability of the genetic algorithm and the generalization ability of BP neural network, the hybrid vehicle Ni-MH power battery GA-BP charging model is designed. In this approach, the network training speed is superior to the traditional BP network. According to the real-time data of the batteries, the optimal solution can be concluded in a short time and with high estimation precision.
Ultracold Heteronuclear Mixture of Ground and Excited State Atoms
Khramov, Alexander; Dowd, William; Roy, Richard; Makrides, Constantinos; Petrov, Alexander; Kotochigova, Svetlana; Gupta, Subhadeep
2014-01-01
We report on the realization of an ultracold mixture of lithium atoms in the ground state and ytterbium atoms in the excited metastable 3P2 state. Such a mixture can support broad magnetic Feshbach resonances which may be utilized for the production of ultracold molecules with an electronic spin degree of freedom, as well as novel Efimov trimers. We investigate the interaction properties of the mixture in the presence of an external magnetic field and find an upper limit for the background interspecies two-body inelastic decay coefficient of K'2 < 3e-12 cm^3/s for the 3P2 m_J=-1 substate. We calculate the dynamic polarizabilities of the Yb 3P2 magnetic substates for a range of wavelengths, and find good agreement with our measurements at 1064nm. Our calculations also allow the identification of magic frequencies where Yb ground and metastable states are identically trapped and the determination of the interspecies van der Waals coefficients.
The lowest-energy charge-transfer state and its role in charge separation in organic photovoltaics.
Nan, Guangjun; Zhang, Xu; Lu, Gang
2016-06-29
Energy independent, yet higher than 90% internal quantum efficiency (IQE), has been observed in many organic photovoltaics (OPVs). However, its physical origin remains largely unknown and controversial. The hypothesis that the lowest charge-transfer (CT) state may be weakly bound at the interface has been proposed to rationalize the experimental observations. In this paper, we study the nature of the lowest-energy CT (CT1) state, and show conclusively that the CT1 state is localized in typical OPVs. The electronic couplings in the donor and acceptor are found to determine the localization of the CT1 state. We examine the geminate recombination of the CT1 state and estimate its lifetime from first principles. We identify the vibrational modes that contribute to the geminate recombination. Using material parameters determined from first principles and experiments, we carry out kinetic Monte Carlo simulations to examine the charge separation of the localized CT1 state. We find that the localized CT1 state can indeed yield efficient charge separation with IQE higher than 90%. Dynamic disorder and configuration entropy can provide the energetic and entropy driving force for charge separation. Charge separation efficiency depends more sensitively on the dimension and crystallinity of the acceptor parallel to the interface than that normal to the interface. Reorganization energy is found to be the most important material parameter for charge separation, and lowering the reorganization energy of the donor should be pursued in the materials design.
Ground State Correlations and the Multiconfiguration Mixing Method
Pillet, N; Van Giai, N; Berger, J F; Giai, Nguyen Van
2004-01-01
We study the convergence properties of a truncation scheme in describing the ground state properties of a many-particle system of fermions. The model wave function is built within a multiconfiguration mixing approach where the many-body wave function is described as a superposition of multiparticle-multihole configurations constructed upon a Slater determinant. The convergence properties of physical quantities such as correlation energies and single-particle occupation probabilities in terms of the increasing number of particle-hole configurations are investigated for the case of an exactly solvable pairing hamiltonian.
Ground-state spin of {sup 59}Mn
Oinonen, M.; Koester, U.; Aeystoe, J. [CERN, Geneva (Switzerland). EP Div.; Fedoseyev, V.; Mishin, V. [Rossijskaya Akademiya Nauk, Troitsk (Russian Federation). Inst. Spektroskopii; Huikari, J.; Jokinen, A.; Nieminen, A.; Peraejaervi, K. [Jyvaeskylae Univ. (Finland). Dept. of Physics; Knipper, A.; Walter, G. [Institute de Recherches Subatomiques, 67 - Strasbourg (France)
2001-02-01
Beta-decay of {sup 59}Mn has been studied at PSB-ISOLDE, CERN. The intense and pure Mn beam was produced using the Resonance Ionization Laser Ion Source (RILIS). Based on the measured {beta}-decay rates the ground-state spin and parity are proposed to be J{sup {pi}} = 5/2{sup -}. This result is consistent with the systematic trend of the odd-A Mn nuclei and extends the systematics one step further towards the neutron drip line. (orig.)
Triaxiality near the 110Ru ground state from Coulomb excitation
Doherty, D. T.; Allmond, J. M.; Janssens, R. V. F.; Korten, W.; Zhu, S.; Zielińska, M.; Radford, D. C.; Ayangeakaa, A. D.; Bucher, B.; Batchelder, J. C.; Beausang, C. W.; Campbell, C.; Carpenter, M. P.; Cline, D.; Crawford, H. L.; David, H. M.; Delaroche, J. P.; Dickerson, C.; Fallon, P.; Galindo-Uribarri, A.; Kondev, F. G.; Harker, J. L.; Hayes, A. B.; Hendricks, M.; Humby, P.; Girod, M.; Gross, C. J.; Klintefjord, M.; Kolos, K.; Lane, G. J.; Lauritsen, T.; Libert, J.; Macchiavelli, A. O.; Napiorkowski, P. J.; Padilla-Rodal, E.; Pardo, R. C.; Reviol, W.; Sarantites, D. G.; Savard, G.; Seweryniak, D.; Srebrny, J.; Varner, R.; Vondrasek, R.; Wiens, A.; Wilson, E.; Wood, J. L.; Wu, C. Y.
2017-03-01
A multi-step Coulomb excitation measurement with the GRETINA and CHICO2 detector arrays was carried out with a 430-MeV beam of the neutron-rich 110Ru (t1/2 = 12 s) isotope produced at the CARIBU facility. This represents the first successful measurement following the post-acceleration of an unstable isotope of a refractory element. The reduced transition probabilities obtained for levels near the ground state provide strong evidence for a triaxial shape; a conclusion confirmed by comparisons with the results of beyond-mean-field and triaxial rotor model calculations.
Evidence for the ground-state resonance of 26O
Lunderberg, E; Kohley, Z; Attanayake, H; Baumann, T; Bazin, D; Christian, G; Divaratne, D; Grimes, S M; Haagsma, A; Finck, J E; Frank, N; Luther, B; Mosby, S; Nagy, T; Peaslee, G F; Schiller, A; Snyder, J; Spyrou, A; Strongman, M J; Thoennessen, M
2012-01-01
Evidence for the ground state of the neutron-unbound nucleus 26O was observed for the first time in the single proton-knockout reaction from a 82 MeV/u 27F beam. Neutrons were measured in coincidence with 24O fragments. 26O was determined to be unbound by 150+50-150 keV from the observation of low-energy neutrons. This result agrees with recent shell model calculations based on microscopic two- and three-nucleon forces.
First Observation of Ground State Dineutron Decay: Be16
Spyrou, A.; Kohley, Z.; Baumann, T.; Bazin, D.; Brown, B. A.; Christian, G.; Deyoung, P. A.; Finck, J. E.; Frank, N.; Lunderberg, E.; Mosby, S.; Peters, W. A.; Schiller, A.; Smith, J. K.; Snyder, J.; Strongman, M. J.; Thoennessen, M.; Volya, A.
2012-03-01
We report on the first observation of dineutron emission in the decay of Be16. A single-proton knockout reaction from a 53MeV/u B17 beam was used to populate the ground state of Be16. Be16 is bound with respect to the emission of one neutron and unbound to two-neutron emission. The dineutron character of the decay is evidenced by a small emission angle between the two neutrons. The two-neutron separation energy of Be16 was measured to be 1.35(10) MeV, in good agreement with shell model calculations, using standard interactions for this mass region.
Ground state of a confined Yukawa plasma including correlation effects
Henning, C; Filinov, A; Piel, A; Bonitz, M
2007-01-01
The ground state of an externally confined one-component Yukawa plasma is derived analytically using the local density approximation (LDA). In particular, the radial density profile is computed. The results are compared with the recently obtained mean-field (MF) density profile \\cite{henning.pre06}. While the MF results are more accurate for weak screening, LDA with correlations included yields the proper description for large screening. By comparison with first-principle simulations for three-dimensional spherical Yukawa crystals we demonstrate that both approximations complement each other. Together they accurately describe the density profile in the full range of screening parameters.
Ground state hyperfine splitting of high Z hydrogenlike ions
Shabaev, V M; Kühl, T; Artemiev, A N; Yerokhin, V A
1997-01-01
The ground state hyperfine splitting values of high Z hydrogenlike ions are calculated. The relativistic, nuclear and QED corrections are taken into account. The nuclear magnetization distribution correction (the Bohr-Weisskopf effect) is evaluated within the single particle model with the g_{S}-factor chosen to yield the observed nuclear moment. An additional contribution caused by the nuclear spin-orbit interaction is included in the calculation of the Bohr-Weisskopf effect. It is found that the theoretical value of the wavelength of the transition between the hyperfine splitting components in ^{165}Ho^{66+} is in good agreement with experiment.
Photoabsorption by ground-state alkali-metal atoms.
Weisheit, J. C.
1972-01-01
Principal-series oscillator strengths and ground-state photoionization cross sections are computed for sodium, potassium, rubidium, and cesium. The degree of polarization of the photoelectrons is also predicted for each atom. The core-polarization correction to the dipole transition moment is included in all of the calculations, and the spin-orbit perturbation of valence-p-electron orbitals is included in the calculations of the Rb and Cs oscillator strengths and of all the photoionization cross sections. The results are compared with recent measurements.
Boersma, C.; Bregman, J.; Allamandola, L. J.
2016-11-01
Low-resolution Spitzer spectral map data (>1700 spectra) of ten reflection nebulae (RNe) fields are analyzed using the data and tools available through the NASA Ames PAH IR Spectroscopic Database. The PAH emission is broken down into PAH charge state using a database fitting approach. Here, the physics of the PAH emission process is taken into account and uses target appropriate parameters, e.g., a stellar radiation model for the exciting star. The breakdown results are combined with results derived using the traditional PAH band strength approach, which interprets particular PAH band strength ratios as proxies for the PAH charge state, e.g., the 6.2/11.2 μm PAH band strength ratio. These are successfully calibrated against their database equivalent; the PAH ionized fraction (f i ). The PAH ionized fraction is converted into the PAH ionization parameter, which relates the PAH ionized fraction to the strength of the radiation field, gas temperature and electron density. The behavior of the 12.7 μm PAH band is evaluated as a tracer for PAH ionization and erosion. The plot of the 8.6 versus 11.2 μm PAH band strength for the northwest photo-dominated region (PDR) in NGC 7023 is shown to be a robust diagnostic template for the PAH ionized fraction. Remarkably, most of the other RNe fall within the limits set by NGC 7023. Finally, PAH spectroscopic templates are constructed and verified as principal components. Template spectra derived from NGC 7023 and NGC 2023 compare extremely well with each other, with those derived for NGC 7023 successfully reproducing the PAH emission observed from NGC 2023.
Wilhelm, Richard A.; Gruber, Elisabeth; Smejkal, Valerie; Facsko, Stefan; Aumayr, Friedrich
2016-05-01
We report on energy loss measurements of slow (v ≪v0 ), highly charged (Q >10 ) ions upon transmission through a 1-nm-thick carbon nanomembrane. We emphasize here the scaling of the energy loss with the velocity and charge exchange or loss. We show that a weak linear velocity dependence exists, whereas charge exchange dominates the kinetic energy loss, especially in the case of a large charge capture. A universal scaling of the energy loss with the charge exchange and velocity is found and discussed in this paper. A model for charge-state-dependent energy loss for slow ions is presented in paper II in this series [R. A. Wilhelm and W. Möller, Phys. Rev. A 93, 052709 (2016), 10.1103/PhysRevA.93.052709].
Universal crossover from ground-state to excited-state quantum criticality
Kang, Byungmin; Potter, Andrew C.; Vasseur, Romain
2017-01-01
We study the nonequilibrium properties of a nonergodic random quantum chain in which highly excited eigenstates exhibit critical properties usually associated with quantum critical ground states. The ground state and excited states of this system belong to different universality classes, characterized by infinite-randomness quantum critical behavior. Using strong-disorder renormalization group techniques, we show that the crossover between the zero and finite energy density regimes is universal. We analytically derive a flow equation describing the unitary dynamics of this isolated system at finite energy density from which we obtain universal scaling functions along the crossover.
Kleinlein, Claudia; Zheng, Shao-Liang; Betley, Theodore A.
2017-04-24
Three ferric dipyrromethene complexes featuring different ancillary ligands were synthesized by one electron oxidation of ferrous precursors. Four-coordinate iron complexes of the type (^{Ar}L)FeX_{2} [^{Ar}L = 1,9-(2,4,6-Ph_{3}C_{6}H_{2})_{2}-5-mesityldipyrromethene] with X = Cl or ^{t}BuO were prepared and found to be high-spin (S = 5/2), as determined by superconducting quantum interference device magnetometry, electron paramagnetic resonance, and ^{57}Fe Mössbauer spectroscopy. The ancillary ligand substitution was found to affect both ground state and excited properties of the ferric complexes examined. While each ferric complex displays reversible reduction and oxidation events, each alkoxide for chloride substitution results in a nearly 600 mV cathodic shift of the Fe^{III/II} couple. The oxidation event remains largely unaffected by the ancillary ligand substitution and is likely dipyrrin-centered. While the alkoxide substituted ferric species largely retain the color of their ferrous precursors, characteristic of dipyrrin-based ligand-to-ligand charge transfer (LLCT), the dichloride ferric complex loses the prominent dipyrrin chromophore, taking on a deep green color. Time-dependent density functional theory analyses indicate the weaker-field chloride ligands allow substantial configuration mixing of ligand-to-metal charge transfer into the LLCT bands, giving rise to the color changes observed. Furthermore, the higher degree of covalency between the alkoxide ferric centers is manifest in the observed reactivity. Delocalization of spin density onto the tert-butoxide ligand in (^{Ar}L)FeCl(O^{t}Bu) is evidenced by hydrogen atom abstraction to yield (^{Ar}L)FeCl and HOtBu in the presence of substrates containing weak C–H bonds, whereas the chloride (^{Ar}L)FeCl_{2} analogue does not react under these conditions.
Peierls ground state and excitations in the electron-lattice correlated system (EDO-TTF)2X
Tsuchiizu, M.; Suzumura, Y.
2008-05-01
We investigate the exotic Peierls state in the one-dimensional organic compound (EDO-TTF)2X , wherein the Peierls transition is accompanied by the bending of molecules and also by a fourfold periodic array of charge disproportionation along the one-dimensional chain. Such a Peierls state, wherein the interplay between the electron correlation and the electron-phonon interaction takes an important role, is examined based on an extended Peierls Holstein Hubbard model that includes the alternation of the elastic energies for both the lattice distortion and the molecular deformation. The model reproduces the experimentally observed pattern of the charge disproportionation and there exists a metastable state wherein the energy takes a local minimum with respect to the lattice distortion and/or molecular deformation. Furthermore, we investigate the excited states for both the Peierls ground state and the metastable state by considering the soliton formation of electrons. It is shown that the soliton excitation from the metastable state costs energy that is much smaller than that of the Peierls state, where the former is followed only by the charge degree of freedom and the latter is followed by that of spin and charge. Based on these results, we discuss the exotic photoinduced phase found in (EDO-TTF)2PF6 .
Uniqueness of ground states of some coupled nonlinear Schrodinger systems and their application
MA,LI; Lin ZHAO
2007-01-01
We establish the uniqueness of ground states of some coupled nonlinear Schrodinger systems in the whole space. We firstly use Schwartz symmetrization to obtain the existence of ground states for a more general case. To prove the uniqueness of ground states, we use the radial symmetry of the ground states to transform the systems into an ordinary differential system, and then we use the integral forms of the system. More interestingly, as an application of our uniqueness results, we derive a s...
Eigenvectors in the superintegrable model II: ground-state sector
Au-Yang, Helen; Perk, Jacques H H [Department of Physics, Oklahoma State University, 145 Physical Sciences, Stillwater, OK 74078-3072 (United States)], E-mail: helenperk@yahoo.com, E-mail: perk@okstate.edu
2009-09-18
In 1993, Baxter gave 2{sup m{sub Q}} eigenvalues of the transfer matrix of the N-state superintegrable chiral Potts model with the spin-translation quantum number Q, where m{sub Q} = lfloor(NL - L - Q)/Nrfloor. In our previous paper we studied the Q = 0 ground-state sector, when the size L of the transfer matrix is chosen to be a multiple of N. It was shown that the corresponding {tau}{sub 2} matrix has a degenerate eigenspace generated by the generators of r = m{sub 0} simple sl{sub 2} algebras. These results enable us to express the transfer matrix in the subspace in terms of these generators E{sup {+-}}{sub m} and H{sub m} for m = 1, ..., r. Moreover, the corresponding 2{sup r} eigenvectors of the transfer matrix are expressed in terms of rotated eigenvectors of H{sub m}.
Theoretical study on thermal decomposition of azoisobutyronitrile in ground state
SUN Chengke; ZHAO Hongmei; LI Zonghe
2004-01-01
The thermal decomposition mechanisms of azoisobutyronitrile (AIBN) in the ground state have been investigated systematically. Based on the potential energy surfaces (PES) of various possible dissociation paths obtained using the semiempirical AM1 method with partial optimization, the density function theory B3LYP/6-311G* method was employed to optimize the geometric parameters of the reactants, the intermediates, the products and the transition states,which were further confirmed by the vibrational analysis. The obtained results show that the reaction process of the two-bond (three-body) simultaneous cleavage Me2(CN)C-N=Nleading to the reaction proceeding in the former pathway. The calculation results were consistent with all the experimental facts.
Ground state for CH2 and symmetry for methane decomposition
Zhang Li; Luo Wen-Lang; Ruan Wen; Jiang Gang; Zhu Zheng-He
2008-01-01
Using the different level of methods B3P86, BLYP, B3PW91, HF, QCISD, CASSCF (4,4) and MP2 with the various basis functions 6-311G**, D95, cc-pVTZ and DGDZVP, the calculations of this paper confirm that the ground state is X3B1 with C2v group for CH2. Furthermore, the three kinds of theoretical methods, I.e. B3P86, CCSD(T, MP4) and G2 with the same basis set cc-pVTZ only are used to recalculate the zero-point energy revision which are modified by scaling factor 0.989 for the high level based on the virial theorem, and also with the correction for basis set superposition error. These results are also contrary to X3Σ-g for the ground state of CH2 in reference. Based on the atomic and molecular reaction statics, this paper proves that the decomposition type (1) I.e. CH4→CH2+H2, is forbidden and the decomposition type (2) I.e. CH4→CH3+H is allowed for CH4. This is similar to the decomposition of SiH4.
Ground-state electronic structure of actinide monocarbides and mononitrides
Petit, Leon; Svane, Axel; Szotek, Z.
2009-01-01
The self-interaction corrected local spin-density approximation is used to investigate the ground-state valency configuration of the actinide ions in the actinide monocarbides, AC (A=U,Np,Pu,Am,Cm), and the actinide mononitrides, AN. The electronic structure is characterized by a gradually...... increasing degree of f electron localization from U to Cm, with the tendency toward localization being slightly stronger in the (more ionic) nitrides compared to the (more covalent) carbides. The itinerant band picture is found to be adequate for UC and acceptable for UN, while a more complex manifold...... of competing localized and delocalized f-electron configurations underlies the ground states of NpC, PuC, AmC, NpN, and PuN. The fully localized 5f-electron configuration is realized in CmC (f7), CmN (f7), and AmN (f6). The observed sudden increase in lattice parameter from PuN to AmN is found to be related...
Au42: A possible ground-state noble metallic nanotube
Wang, Jing; Ning, Hua; Ma, Qing-Min; Liu, Ying; Li, You-Cheng
2008-10-01
A large hollow tubelike Au42 is predicted as a new ground-state configuration based on the scalar relativistic density functional theory. The shape of this new Au42 cluster is similar to a (5,5) single-wall gold nanotube, the two ends of which are capped by half of a fullerenelike Au32. In the same way, a series of Aun (n =37,42,47,52,57,62,67,72,…, Δn =5) tubelike structures has been constructed. The highest occupied molecular orbital-lowest unoccupied molecular orbital gaps suggested a significant semiconductor-conductor alternation in n ɛ[32,47]. Similar to the predictions and speculation of Daedalus [D. E. H. Jones, New Sci. 32, 245 (1966); E. Osawa, Superaromaticity (Kagaku, Kyoto, 1970), Vol. 25, pp. 854-863; Z. Yoshida and E. Osawa, Aromaticity Chemical Monograph (Kagaku Dojin, Kyoto, Japan, 1971), Vol. 22, pp. 174-176; D. A. Bochvar and E. G. Gal'pern, Dokl. Akad. Nauk SSSR 209, 610 (1973)], here a large hollow ground-state gold nanotube was predicted theoretically.
On the nature of the oligoacene ground state
Hachmann, Johannes; Dorando, Jonathan; Aviles, Michael; Kin-Lic Chan, Garnet
2007-03-01
The nature of the oligoacene ground state - its spin, singlet-triplet gap, and diradical character as a function of chain-length - is a question of ongoing theoretical and experimental interest with notable technological implications. Previous computational studies have given inconclusive answers to this challenging electronic structure problem (see e.g. [1]). In the present study we exploit the capabilities of the local ab initio Density Matrix Renormalization Group (DMRG) [2], which allows the numerically exact (FCI) solution of the Schr"odinger equation in a chosen 1-particle basis and active space for quasi-one-dimensional systems. We compute the singlet-triplet gap from first principles as a function of system length ranging from naphthalene to tetradecacene, correlating the full π-space (i.e. up to 58 electrons in 58 orbitals) and converging the results to a few μEh accuracy [3]. In order to study the diradical nature of the oligoacene ground state we calculate expectation values over different diradical occupation and pair-correlation operators. Furthermore we study the natural orbitals and their occupation. [1] Bendikov, Duong, Starkey, Houk, Carter, Wudl, JACS 126 (2004), 7416. [2] Hachmann, Cardoen, Chan, JCP 125 (2006), 144101. [3] Hachmann, Dorando, Avil'es, Chan, in preparation.
Low charge state heavy ion production with sub-nanosecond laser
Kanesue, T., E-mail: tkanesue@bnl.gov; Okamura, M. [Collider-Accelerator Department, Brookhaven National Laboratory, Upton, New York 11973 (United States); Kumaki, M. [Research Institute for Science and Engineering, Waseda University, Tokyo 169-8555 (Japan); Nishina Center for Accelerator-Based Science, RIKEN, Saitama 351-0198 (Japan); Ikeda, S. [Nishina Center for Accelerator-Based Science, RIKEN, Saitama 351-0198 (Japan); Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, Kanagawa 226-8503 (Japan)
2016-02-15
We have investigated laser ablation plasma of various species using nanosecond and sub-nanosecond lasers for both high and low charge state ion productions. We found that with sub-nanosecond laser, the generated plasma has a long tail which has low charge state ions determined by an electrostatic ion analyzer even under the laser irradiation condition for highly charged ion production. This can be caused by insufficient laser absorption in plasma plume. This property might be suitable for low charge state ion production. We used a nanosecond laser and a sub-nanosecond laser for low charge state ion production to investigate the difference of generated plasma using the Zirconium target.
Low charge state heavy ion production with sub-nanosecond laser.
Kanesue, T; Kumaki, M; Ikeda, S; Okamura, M
2016-02-01
We have investigated laser ablation plasma of various species using nanosecond and sub-nanosecond lasers for both high and low charge state ion productions. We found that with sub-nanosecond laser, the generated plasma has a long tail which has low charge state ions determined by an electrostatic ion analyzer even under the laser irradiation condition for highly charged ion production. This can be caused by insufficient laser absorption in plasma plume. This property might be suitable for low charge state ion production. We used a nanosecond laser and a sub-nanosecond laser for low charge state ion production to investigate the difference of generated plasma using the Zirconium target.
High Intensity High Charge State ECR Ion Sources
Leitner, Daniela
2005-01-01
The next-generation heavy ion beam accelerators such as the proposed Rare Isotope Accelerator (RIA), the Radioactive Ion Beam Factory at RIKEN, the GSI upgrade project, the LHC-upgrade, and IMP in Lanzhou require a great variety of high charge state ion beams with a magnitude higher beam intensity than currently achievable. High performance Electron Cyclotron Resonance (ECR) ion sources can provide the flexibility since they can routinely produce beams from hydrogen to uranium. Over the last three decades, ECR ion sources have continued improving the available ion beam intensities by increasing the magnetic fields and ECR heating frequencies to enhance the confinement and the plasma density. With advances in superconducting magnet technology, a new generation of high field superconducting sources is now emerging, designed to meet the requirements of these next generation accelerator projects. The talk will briefly review the field of high performance ECR ion sources and the latest developments for high intens...
State of charge estimation in Ni-MH rechargeable batteries
Milocco, R.H. [Grupo Control Automatico y Sistemas (GCAyS), Depto. Electrotecnia, Facultad de Ingenieria, Universidad Nacional del Comahue, Buenos Aires 1400, 8300 Neuquen (Argentina); Castro, B.E. [Instituto de Investigaciones Fisicoquimicas Teoricas y Aplicadas (INIFTA), Universidad Nacional de La Plata, Suc 4, CC16 (1900), La Plata (Argentina)
2009-10-20
In this work we estimate the state of charge (SOC) of Ni-MH rechargeable batteries using the Kalman filter based on a simplified electrochemical model. First, we derive the complete electrochemical model of the battery which includes diffusional processes and kinetic reactions in both Ni and MH electrodes. The full model is further reduced in a cascade of two parts, a linear time invariant dynamical sub-model followed by a static nonlinearity. Both parts are identified using the current and potential measured at the terminals of the battery with a simple 1-D minimization procedure. The inverse of the static nonlinearity together with a Kalman filter provide the SOC estimation as a linear estimation problem. Experimental results with commercial batteries are provided to illustrate the estimation procedure and to show the performance. (author)
Absence of State Collapse and Revival in a Superconducting Charge Qubit
无
2007-01-01
The Hamiltonian of a superconducting charge qubit with a configuration of dc SQUID contains an interaction between the LC oscillator part and charge qubit. This interaction may leads to quantum state collapse and revival which degrades the charge qubits and leads to serious decoherence. An analysis shows that the existing charge qubit parameters do not lead to this phenomenon, which is very good for the superconducting charge qubit.
Morales, Roberto; Casas, David
2016-01-01
The instantaneous charge state of uranium ions traveling through a fully ionized hydrogen plasma has been theoretically studied and compared with one of the first energy loss experiments in plasmas, carried out at GSI-Darmstadt by Hoffmann \\textit{et al.} in the 90's. For this purpose, two different methods to estimate the instantaneous charge state of the projectile have been employed: (1) rate equations using ionization and recombination cross sections, and (2) equilibrium charge state formulas for plasmas. Also, the equilibrium charge state has been obtained using these ionization and recombination cross sections, and compared with the former equilibrium formulas. The equilibrium charge state of projectiles in plasmas is not always reached, it depends mainly on the projectile velocity and the plasma density. Therefore, a non-equilibrium or an instantaneous description of the projectile charge is necessary. The charge state of projectile ions cannot be measured, except after exiting the target, and experime...
Xu, X X; Sun, L J; Wang, J S; Lam, Y H; Lee, J; Fang, D Q; Li, Z H; Smirnova, N A; Yuan, C X; Yang, L; Wang, Y T; Li, J; Ma, N R; Wang, K; Zang, H L; Wang, H W; Li, C; Liu, M L; Wang, J G; Shi, C Z; Nie, M W; Li, X F; Li, H; Ma, J B; Ma, P; Jin, S L; Huang, M R; Bai, Z; Yang, F; Jia, H M; Liu, Z H; Wang, D X; Yang, Y Y; Zhou, Y J; Ma, W H; Chen, J; Hu, Z G; Zhang, Y H; Ma, X W; Zhou, X H; Ma, Y G; Xu, H S; Xiao, G Q; Zhang, H Q
2016-01-01
The decay of the proton-rich nucleus $^{22}$Si was studied by a silicon array coupled with germanium clover detectors. Nine charged-particle groups are observed and most of them are recognized as $\\beta$-delayed proton emission. A charged-particle group at 5600 keV is identified experimentally as $\\beta$-delayed two-proton emission from the isobaric analog state of $^{22}$Al. Another charged-particle emission without any $\\beta$ particle at the low energy less than 300 keV is observed. The half-life of $^{22}$Si is determined as 27.5 (18) ms. The experimental results of $\\beta$-decay of $^{22}$Si are compared and in nice agreement with shell-model calculations. The mass excess of the ground state of $^{22}$Si deduced from the experimental data shows that three-nucleon (3N) forces with repulsive contributions have significant effects on nuclei near the proton drip line.
Wickholm, D.; Bickel, W. S.
1976-01-01
The paper describes an experiment consisting of the acceleration of N(+) and N2(+) ions to energies between 0.25 and 1.75 MeV and their injection through a thin carbon foil, whereupon they were charge-state analyzed with an electrostatic analyzer. A foil-covered electrically suppressed Faraday cup, connected to a stepping motor, moved in the plane of the dispersed beams. The Faraday cup current, which was proportional to the number of incident ions, was sent to a current digitizer and computer programmed as a multiscaler. The energy-dependent charge-state fractions, the mean charge and the distribution width were calculated. It was shown that for incident atoms, the charge state distribution appeared to be spread over more charge states, while for the incident molecules, there was a greater fraction of charge states near the mean charge.
Ground state configurations in antiferromagnetic ultrathin films with dipolar anisotropy
Leon, H., E-mail: hleon@imre.oc.uh.cu [Instituto de Ciencia y Tecnologia de Materiales, Universidad de La Habana, Zapata e/ Mazon y G. Vedado, 10400 La Habana (Cuba)
2013-02-15
The formalism developed in a previous work to calculate the dipolar energy in quasi-two-dimensional crystals with ferromagnetic order is now extended to collinear antiferromagnetic order. Numerical calculations of the dipolar energy are carried out for systems with tetragonally distorted fcc [001] structures, the case of NiO and MnO ultrathin film grown in non-magnetic substrates, where the magnetic phase is a consequence of superexchange and dipolar interactions. The employed approximation allows to demonstrate that dipolar coupling between atomic layers is responsible for the orientation of the magnetization when it differs from the one in a single layer. The ground state energy of a given NiO or MnO film is found to depend not only on the strain, but also on how much the interlayer separation and the 2D lattice constant are changed with respect to the ideal values corresponding to the non-distorted cubic structure. Nevertheless, it is shown that the orientation of the magnetization in the magnetic phase of any of these films is determined by the strain exclusively. A striped phase with the magnetization along the [112{sup Macron }] direction appears as the ground state configuration of NiO and MnO ultrathin films. In films with equally oriented stripes along the layers this magnetic phase is twofold degenerate, while in films with multidomain layers it is eightfold degenerate. These results are not in contradiction with experimentally observed out-of-plane or in-plane magnetization of striped phases in NiO and MnO ultrathin films. - Highlights: Black-Right-Pointing-Pointer Dipolar energy in collinear antiferromagnetic ultrathin films is calculated. Black-Right-Pointing-Pointer Numerical results are presented for distorted fcc [001] structures. Black-Right-Pointing-Pointer The lowest energy of a system depends on how the tetragonal distortion is achieved. Black-Right-Pointing-Pointer A striped phase with magnetization in the [112{sup Macron }] direction is the
Covariant energy density functionals: nuclear matter constraints and global ground state properties
Afanasjev, A V
2016-01-01
The correlations between global description of the ground state properties (binding energies, charge radii) and nuclear matter properties of the state-of-the-art covariant energy density functionals have been studied. It was concluded that the strict enforcement of the constraints on the nuclear matter properties (NMP) defined in Ref.\\ \\cite{RMF-nm} will not necessary lead to the functionals with good description of the binding energies and other ground and excited state properties. In addition, it will not substantially reduce the uncertainties in the predictions of the binding energies in neutron-rich systems. It turns out that the functionals, which come close to satisfying these NMP constraints, have some problems in the description of existing data. On the other hand, these problems are either absent or much smaller in the functionals which are carefully fitted to finite nuclei but which violate some NMP constraints. This is a consequence of the fact that the properties of finite nuclei are defined not o...
Diagnostics of many-particle electronic states: non-stationary currents and residual charge dynamics
Maslova, N. S.; Mantsevich, V. N.; Arseyev, P. I.
2017-01-01
We propose the method for identifying many particle electronic states in the system of coupled quantum dots (impurities) with Coulomb correlations. We demonstrate that different electronic states can be distinguished by the complex analysis of localized charge dynamics and non-stationary characteristics. We show that localized charge time evolution strongly depends on the properties of initial state and analyze different time scales in charge kinetics for initially prepared singlet and triplet states. We reveal the conditions for existence of charge trapping effects governed by the selection rules for electron transitions between the states with different occupation numbers.
LABS problem and ground state spin glasses system
Leukhin, A. N.; Bezrodnyi, V. I.; Kozlova, Yu. A.
2016-12-01
In our work we demonstrate the new results of an exhaustive search for optimal binary sequences with minimum peak sidelobe (MPS) up to length N=85. The design problem for law autocorrelation binary sequences (LABS) is a notoriously difficult computational problem which is numbered as the problem number 005 in CSPLib. In statistical physics LABS problem can be interrepted as the energy of N iteracting Ising spins. This is a Bernasconi model. Due to this connection to physics we refer a binary sequence as one-dimensional spin lattice. At this assumption optimal binary sequences by merit factor (MF) criteria are the ground-state spin system without disorder which exhibits a glassy regime.
Ground state structures and properties of small hydrogenated silicon clusters
R Prasad
2003-01-01
We present results for ground state structures and properties of small hydrogenated silicon clusters using the Car–Parrinello molecular dynamics with simulated annealing. We discuss the nature of bonding of hydrogen in these clusters. We find that hydrogen can form a bridge like Si–H–Si bond connecting two silicon atoms. We find that in the case of a compact and closed silicon cluster hydrogen bonds to the silicon cluster from outside. To understand the structural evolutions and properties of silicon cluster due to hydrogenation, we have studied the cohesive energy and first excited electronic level gap of clusters as a function of hydrogenation. We find that first excited electronic level gap of Si and SiH fluctuates as function of size and this may provide a first principle basis for the short-range potential fluctuations in hydrogenated amorphous silicon. The stability of hydrogenated silicon clusters is also discussed.
Ground-state correlations within a nonperturbative approach
De Gregorio, G.; Herko, J.; Knapp, F.; Lo Iudice, N.; Veselý, P.
2017-02-01
The contribution of the two-phonon configurations to the ground state of 4He and 16O is evaluated nonperturbatively using a Hartree-Fock basis within an equation-of-motion phonon method using a nucleon-nucleon optimized chiral potential. Convergence properties of energies and root-mean-square radii versus the harmonic oscillator frequency and space dimensions are investigated. The comparison with the second-order perturbation theory calculations shows that the higher-order terms have an appreciable repulsive effect and yield too-small binding energies and nuclear radii. It is argued that four-phonon configurations, through their strong coupling to two phonons, may provide most of the attractive contribution necessary for filling the gap between theoretical and experimental quantities. Possible strategies for accomplishing such a challenging task are discussed.
Potential Energy Surfaces of Nitrogen Dioxide for the Ground State
SHAO Ju-Xiang; ZHU Zheng-He; CHENG Xin-Lu; YANG Xiang-Dong
2007-01-01
The potential energy function of nitrogen dioxide with the C2v symmetry in the ground state is represented using the simplified Sorbie-Murrell many-body expansion function in terms of the symmetry of NO2. Using the potential energy function, some potential energy surfaces of NO2(C2v, X2A1), such as the bond stretching contour plot for a fixed equilibrium geometry angle θ and contour for O moving around N-O (R1), in which R1 is fixed at the equilibrium bond length, are depicted. The potential energy surfaces are analysed. Moreover, the equilibrium parameters for NO2 with the C2v, Cs and D8h symmetries, such as equilibrium geometry structures and energies, are calculated by the ab initio (CBS-Q) method.
Sympathetic cooling of molecular ion motion to the ground state
Rugango, Rene; Dixon, Thomas H; Gray, John M; Khanyile, Ncamiso; Shu, Gang; Clark, Robert J; Brown, Kenneth R
2014-01-01
We demonstrate sympathetic sideband cooling of a $^{40}$CaH$^{+}$ molecular ion co-trapped with a $^{40}$Ca$^{+}$ atomic ion in a linear Paul trap. Both axial modes of the two-ion chain are simultaneously cooled to near the ground state of motion. The center of mass mode is cooled to an average quanta of harmonic motion $\\overline{n}_{\\mathrm{COM}} = 0.13 \\pm 0.03$, corresponding to a temperature of $12.47 \\pm 0.03 ~\\mu$K. The breathing mode is cooled to $\\overline{n}_{\\mathrm{BM}} = 0.05 \\pm 0.02$, corresponding to a temperature of $15.36 \\pm 0.01~\\mu$K.
Ground-state properties of neutron magic nuclei
Saxena, G., E-mail: gauravphy@gmail.com [Govt. Women Engineering College, Department of Physics (India); Kaushik, M. [Shankara Institute of Technology, Department of Physics (India)
2017-03-15
A systematic study of the ground-state properties of the entire chains of even–even neutron magic nuclei represented by isotones of traditional neutron magic numbers N = 8, 20, 40, 50, 82, and 126 has been carried out using relativistic mean-field plus Bardeen–Cooper–Schrieffer approach. Our present investigation includes deformation, binding energy, two-proton separation energy, single-particle energy, rms radii along with proton and neutron density profiles, etc. Several of these results are compared with the results calculated using nonrelativistic approach (Skyrme–Hartree–Fock method) along with available experimental data and indeed they are found with excellent agreement. In addition, the possible locations of the proton and neutron drip-lines, the (Z, N) values for the new shell closures, disappearance of traditional shell closures as suggested by the detailed analyzes of results are also discussed in detail.
Radiative charge transfer lifetime of the excited state of (NaCa)$^+$
Makarov, O P; Michels, H J; Smith, W W; Makarov, Oleg P.
2003-01-01
New experiments were proposed recently to investigate the regime of cold atomic and molecular ion-atom collision processes in a special hybrid neutral-atom--ion trap under high vacuum conditions. The collisional cooling of laser pre-cooled Ca$^+$ ions by ultracold Na atoms is being studied. Modeling this process requires knowledge of the radiative lifetime of the excited singlet A$^1\\Sigma^+$ state of the (NaCa)$^+$ molecular system. We calculate the rate coefficient for radiative charge transfer using a semiclassical approach. The dipole radial matrix elements between the ground and the excited states, and the potential curves were calculated using Complete Active Space Self-Consistent field and M\\"oller-Plesset second order perturbation theory (CASSCF/MP2) with an extended Gaussian basis, 6-311+G(3df). The semiclassical charge transfer rate coefficient was averaged over a thermal Maxwellian distribution. In addition we also present elastic collision cross sections and the spin-exchange cross section. The ra...
Point charge embedding for ONIOM excited states calculations
Biancardi, Alessandro; Barnes, Jeremy; Caricato, Marco
2016-12-01
Hybrid quantum mechanical methods can assist in the interpretation and prediction of the electronic spectra of large molecular structures. In this work, we study the performance of the ONIOM (Our own N-layered Integrated molecular Orbital molecular Mechanics) hybrid method for the calculation of transition energies and oscillator strengths by embedding the core region in a field of fixed point charges. These charges introduce polarization effects from the substituent groups to the core region. We test various charge definitions, with particular attention to the issue of overpolarization near the boundary between layers. To minimize this issue, we fit the charges on the electrostatic potential of the entire structure in the presence of the link atoms used to cap dangling bonds. We propose two constrained fitting strategies: one that produces an average set of charges common to both model system calculations, EE(L1), and one that produces two separate sets of embedding charges, EE(L2). The results from our tests show that indeed electronic embedding with constrained-fitted charges tends to improve the performance of ONIOM compared to non-embedded calculations. However, the EE(L2) charges work best for transition energies, and the EE(L1) charges work best for oscillator strengths. This may be an indication that fixed point charges do not have enough flexibility to adapt to each system, and other effects (e.g., polarization of the embedding field) may be necessary.
Ideal charge-density-wave order in the high-field state of superconducting YBCO
Jang, H.; Lee, W.-S.; Nojiri, H.; Matsuzawa, S.; Yasumura, H.; Nie, L.; Maharaj, A. V.; Gerber, S.; Liu, Y.-J.; Mehta, A.; Bonn, D. A.; Liang, R.; Hardy, W. N.; Burns, C. A.; Islam, Z.; Song, S.; Hastings, J.; Devereaux, T. P.; Shen, Z.-X.; Kivelson, S. A.; Kao, C.-C.; Zhu, D.; Lee, J.-S.
2016-12-01
The existence of charge-density-wave (CDW) correlations in cuprate superconductors has now been established. However, the nature of the CDW ground state has remained uncertain because disorder and the presence of superconductivity typically limit the CDW correlation lengths to only a dozen unit cells or less. Here we explore the field-induced 3D CDW correlations in extremely pure detwinned crystals of YBa2Cu3O2 (YBCO) ortho-II and ortho-VIII at magnetic fields in excess of the resistive upper critical field (Hc2Hc2) where superconductivity is heavily suppressed. We observe that the 3D CDW is unidirectional and possesses a long in-plane correlation length as well as significant correlations between neighboring CuO2 planes. It is significant that we observe only a single sharply defined transition at a critical field proportional to Hc2Hc2, given that the field range used in this investigation overlaps with other high-field experiments including quantum oscillation measurements. The correlation volume is at least two to three orders of magnitude larger than that of the zero-field CDW. This is by far the largest CDW correlation volume observed in any cuprate crystal and so is presumably representative of the high-field ground state of an “ideal” disorder-free cuprate.
Ground States and Excited States in a Tunable Graphene Quantum Dot
WANG Lin-Jun; CAO Gang; TU Tao; LI Hai-Ou; ZHOU Cheng; HAO Xiao-Jie; GUO Guang-Can; GUO Guo-Ping
2011-01-01
We prepare an etched gate tunable quantum dot in single-layer graphene and present transport measurement in this system. We extract the information of the ground states and excited states of the graphene quantum dot, as denoted by the presence of characteristic Coulomb blockade diamond diagrams. The results demonstrate that the quantum dot in single-layer graphene bodes well in future quantum transport study and quantum computing applications.%@@ We prepare an etched gate tunable quantum dot in single-layer graphene and present transport measurement in this system.We extract the information of the ground states and excited states of the graphene quantum dot, as denoted by the presence of characteristic Coulomb blockade diamond diagrams.The results demonstrate that the quantum dot in single-layer graphene bodes well in future quantum transport study and quantum computing applications.
Gold, Lukas; Bach, Tobias; Virsik, Wolfgang; Schmitt, Angelika; Müller, Jana; Staab, Torsten E. M.; Sextl, Gerhard
2017-03-01
For electrically powered applications such as consumer electronics and especially for electric vehicles a precise state-of-charge estimation for their lithium-ion batteries is desired to reduce aging, e.g. avoiding detrimental states-of-charge. Today, this estimation is performed by battery management systems that solely rely on charge bookkeeping and cell voltage measurements. In the present work we introduce a new, physical probe for the state-of-charge based on ultrasonic transmission. Within the simple experimental setup raised cosine pulses are applied to lithium-ion battery pouch cells, whose signals are sensitive to changes in porosity of the graphite anode during charging/dis-charging and, therefore, to the state-of-charge. The underlying physical principle can be related to Biot's theory about propagation of waves in fluid saturated porous media and by including scattering by boundary layers inside the cell.
Universal bounds on charged states in 2d CFT and 3d gravity
Benjamin, Nathan; Dyer, Ethan [Stanford Institute for Theoretical Physics, Via Pueblo, Stanford, CA, 94305 (United States); Fitzpatrick, A. Liam [Boston University Physics Department, Commonwealth Avenue, Boston, MA, 02215 (United States); Kachru, Shamit [Stanford Institute for Theoretical Physics, Via Pueblo, Stanford, CA, 94305 (United States)
2016-08-04
We derive an explicit bound on the dimension of the lightest charged state in two dimensional conformal field theories with a global abelian symmetry. We find that the bound scales with c and provide examples that parametrically saturate this bound. We also prove that any such theory must contain a state with charge-to-mass ratio above a minimal lower bound. We comment on the implications for charged states in three dimensional theories of gravity.
Lithium-Ion Battery Failure: Effects of State of Charge and Packing Configuration
2016-08-22
Naval Research Laboratory Washington, DC 20375-5320 NRL/MR/6180--16-9689 Lithium-Ion Battery Failure: Effects of State of Charge and Packing ...PAGES 17. LIMITATION OF ABSTRACT Lithium-Ion Battery Failure: Effects of State of Charge and Packing Configuration Neil S. Spinner,* Katherine M. Hinnant...geometries, abuse scenarios, and analysis techniques. In this report, different states of charge and packing configurations of a commercially available
Universal Bounds on Charged States in 2d CFT and 3d Gravity
Benjamin, Nathan; Fitzpatrick, A Liam; Kachru, Shamit
2016-01-01
We derive an explicit bound on the dimension of the lightest charged state in two dimensional conformal field theories with a global abelian symmetry. We find that the bound scales with $c$ and provide examples that parametrically saturate this bound. We also prove than any such theory must contain a state with charge-to-mass ratio above a minimal lower bound. We comment on the implications for charged states in three dimensional theories of gravity.
Gamiz-Hernandez, Ana P; Magomedov, Artiom; Hummer, Gerhard; Kaila, Ville R I
2015-02-12
Proton-coupled electron transfer (PCET) processes are elementary chemical reactions involved in a broad range of radical and redox reactions. Elucidating fundamental PCET reaction mechanisms are thus of central importance for chemical and biochemical research. Here we use quantum chemical density functional theory (DFT), time-dependent density functional theory (TDDFT), and the algebraic diagrammatic-construction through second-order (ADC(2)) to study the mechanism, thermodynamic driving force effects, and reaction barriers of both ground state proton transfer (pT) and photoinduced proton-coupled electron transfer (PCET) between nitrosylated phenyl-phenol compounds and hydrogen-bonded t-butylamine as an external base. We show that the obtained reaction barriers for the ground state pT reactions depend linearly on the thermodynamic driving force, with a Brønsted slope of 1 or 0. Photoexcitation leads to a PCET reaction, for which we find that the excited state reaction barrier depends on the thermodynamic driving force with a Brønsted slope of 1/2. To support the mechanistic picture arising from the static potential energy surfaces, we perform additional molecular dynamics simulations on the excited state energy surface, in which we observe a spontaneous PCET between the donor and the acceptor groups. Our findings suggest that a Brønsted analysis may distinguish the ground state pT and excited state PCET processes.
Ground State Properties of Ds Isotopes Within the Relativistic Mean Field Theory
张海飞; 张鸿飞; 李君清
2012-01-01
The ground state properties of Ds (Z=110) isotopes (N=151-195) are studied in the framework of the relativistic mean field (RMF) theory with the effective interaction NL-Z2.The pairing correlation is treated within the conventional BCS approximation.The calculated binding energies are consistent with the results from finite-range droplet model (FRDM) and Macroscopic-microscopic method (MMM).The quadrupole deformation,α-decay energy,α-decay half-live,charge radius,two-neutron separation energy and single-particle spectra are analyzed for Ds isotopes to find new characteristics of superheavy nuclei (SHN).Among the calculated results it is rather distinct that the isotopic shift appears evidently at neutron number N=184.
QED calculation of the ground-state energy of berylliumlike ions
Malyshev, A V; Glazov, D A; Tupitsyn, I I; Shabaev, V M; Plunien, G
2014-01-01
\\textit{Ab initio} QED calculations of the ground-state binding energies of berylliumlike ions are performed for the wide range of the nuclear charge number: $Z=18-96$. The calculations are carried out in the framework of the extended Furry picture starting with three different types of the screening potential. The rigorous QED calculations up to the second order of the perturbation theory are combined with the third- and higher-order electron-correlation contributions obtained within the Breit approximation by the use of the large-scale configuration-interaction Dirac-Fock-Sturm method. The effects of nuclear recoil and nuclear polarization are taken into account. The ionization potentials are obtained by subtracting the binding energies of the corresponding lithiumlike ions. In comparison with the previous calculations the accuracy of the binding energies and the ionization potentials is significantly improved.
Christiansen, P.A.; Pitzer, K.S.
1980-07-01
The dissociation curve for the ground state of TlH was computed using a relativistic {omega}-{omega} coupling formalism. The relativistic effects represented by the Dirac equation were introduced using effective potentials generated from atomic Dirac-Fock wave functions using a generalization of the improved effective potential formulation of Christiansen, Lee, and Pitzer. The multiconfiguration SCF treatment used is a generalization of the two-component molecular spinor formalism of Lee, Ermler, and Pitzer. Using a five configuration wave function we were able to obtain approximately 85% of the experimental dissociation energy. Our computations indicate that the bond is principally sigma in form, despite the large spin-orbit splitting in atomic thallium. Furthermore the bond appears to be slightly ionic (Tl{sup +}H{sup -}) with about 0.3 extra electron charge on the hydrogen.
Rendering high charge density of states in ionic liquid-gated MoS 2 transistors
Lee, Y.; Lee, J.; Kim, S.; Park, H.S.
2014-01-01
We investigated high charge density of states (DOS) in the bandgap of MoS2 nanosheets with variable temperature measurements on ionic liquid-gated MoS2 transistors. The thermally activated charge transport indicates that the electrical current in the two-dimensional MoS 2 nanosheets under high charg
A simple scheme to generate x-type four-charge entangled states in circuit QED
Gao Gui-Long; Song Fu-Quan; Huang Shou-Sheng; Wang Hui; Yuan Xian-Zhang; Wang Ming-Feng; Jiang Nian-Quan
2012-01-01
We propose a simple scheme to generate x-type four-charge entangled states by using SQUID-based charge qubits capacitively coupled to a transmission line resonator (TLR).The coupling between the superconducting qubit and the TLR can be effectively controlled by properly adjusting the control parameters of the charge qubit.The experimental feasibility of our scheme is also shown.
Charge state distributions and charge exchange cross sections of carbon in helium at 30-258 keV
Maxeiner, Sascha; Seiler, Martin; Suter, Martin; Synal, Hans-Arno
2015-10-01
With the introduction of helium stripping in radiocarbon (14C) accelerator mass spectrometry (AMS), higher +1 charge state yields in the 200 keV region and fewer beam losses are observed compared to nitrogen or argon stripping. To investigate the feasibility of even lower beam energies for 14C analyses the stripping characteristics of carbon in helium need to be further studied. Using two different AMS systems at ETH Zurich (myCADAS and MICADAS), ion beam transmissions of carbon ions for the charge states -1, +1, +2 and +3 were measured in the range of 258 keV down to 30 keV. The correction for beam losses and the extraction of charge state yields and charge exchange cross sections will be presented. An increase in population of the +1 charge state towards the lowest measured energies up to 75% was found as well as agreement with previous data from literature. The findings suggest that more compact radiocarbon AMS systems are possible and could provide even higher efficiency than current systems operating in the 200 keV range.
Mewes, Jan-Michael; Herbert, John M; Dreuw, Andreas
2017-01-04
Equilibrium and non-equilibrium formulations of the state-specific polarizable-continuum model (SS-PCM) are evaluated in combination with correlated ground- and excited-state densities provided by the algebraic-diagrammatic construction method (ADC) for the polarization propagator via the computationally efficient intermediate-state representation (ISR) formalism. Since the influence of the SS-PCM onto quantum-chemical method is naturally limited to the presence of the apparent surface charges in the one-electron Hamiltonian and hence fully contained in the polarized MOs, the herein presented solvent model can be combined with all implemented orders and variants of ADC. Employing ADC/SS-PCM, the symmetric, ionized dimers of neon, ethene and nitromethane are investigated. Their broken-symmetry wavefunctions exhibit a low-lying charge-transfer state that is symmetry-equivalent to the ground state. This curious though ultimately artificial feature is convenient as it allows for a direct comparison of ADC/SS-PCM for the CT state to the Møller-Plesset/PCM description of the ground state. The agreement down to 0.02 eV for a wide range of dielectric constants validates the ADC/SS-PCM approach. Eventually, the relaxed potential-energy surfaces of the ground and lowest excited states of 4-(N,N)-dimethylaminobenzonitrile in cyclohexane and acetonitrile are computed, and it is demonstrated that the ADC(2)/SS-PCM approach affords excellent agreement with experimental fluorescence data. Only at the ADC(3) level of theory, however, the experimentally observed solvent-dependent dual fluorescence can be explained.
Correlations in the ground state of the one-dimensional Hubbard model
Wang Qingwei, E-mail: wqw03@mails.thu.edu.c [Institute for Advanced Study, Tsinghua University, Beijing 100084 (China); Liu Yuliang, E-mail: ylliu@ruc.edu.c [Department of Physics, Renmin University of China, Beijing 100872 (China)
2009-12-14
With eigenfunctional theory and a rigorous expression of exchange-correlation energy of a general interacting electron system, we study the ground state properties of the one-dimensional Hubbard model, and calculate the ground-state energy as well as the charge gap at half-filling for arbitrary coupling strength u=U/(4t) and electron density n{sub c}. We find that the simple linear approximation of the phase field works well in weak coupling case, but it becomes inappropriate as the on-site Coulomb interaction becomes strong where the fluctuations of the bosonic auxiliary field are strong. Then we propose a new scheme by adding Gutzwiller projection which suppresses the density fluctuations and the new results are quite close to the exact ones up to considerably strong coupling strength u=3.0 and for arbitrary electron density n{sub c}. Our calculation scheme is proved to be effective for strongly correlated electron systems in one dimension, and its extension to higher dimensions is straightforward.
State estimators for tracking sharply-maneuvering ground targets
Visina, Radu S.; Bar-Shalom, Yaakov; Willett, Peter
2017-05-01
This paper presents an algorithm, based on the Interacting Multiple Model Estimator, that can be used to track the state of kinematic point targets, moving in two dimensions, that are capable of making sharp heading maneuvers over short periods of time, such as certain ground vehicles moving in an open field. The targets are capable of up to 60 °/s turn rates, while polar measurements are received at 1 Hz. We introduce the Non-Zero Mean, White Noise Turn-Rate IMM (IMM-WNTR) that consists of 3 modes based on a White Noise Turn Rate (WNTR) kinematic model that contains additive, white, Gaussian turn rate process noises. Two of the modes are considered maneuvering modes, and they have opposite (left/right), non-zero mean turn rate input noise. The need for non-zero mean turn rate process noise is explained, and Monte Carlo simulations compare this novel design to the traditional (single-mode) White Noise Acceleration Kalman Filter (WNA KF) and the two-mode White Noise Acceleration/Nearly-Coordinated Turn Rate IMM (IMM-CT). Results show that the IMM-WNTR filter achieves better accuracy and real-time consistency between expected error and actual error as compared to the (single-mode) WNA KF and the IMM-CT in all simulated scenarios, making it a very accurate state estimator for targets with sharp coordinated turn capability in 2D.
Zero-Point Fluctuations in the Nuclear Born-Oppenheimer Ground State
Zettili, Nouredine
The small-amplitude oscillations of rigid nuclei around the equilibrium state are described by means of the nuclear Born-Oppenheimer (NBO) method. In this limit, the method is shown to give back the random phase approximation (RPA) equations of motion. The contribution of the zero-point fluctuations to the ground state are examined, and the NBO ground state energy derived is shown to be identical to the RPA ground state energy.
Kumari, Rekha; Varghese, Anitha; George, Louis
2017-01-01
Absorption and fluorescence studies on novel Schiff bases (E)-4-(4-(4-nitro benzylideneamino)benzyl)oxazolidin-2-one (NBOA) and (E)-4-(4-(4-chlorobenzylidene amino)benzyl)oxazolidin-2-one (CBOA) were recorded in a series of twelve solvents upon increasing polarity at room temperature. Large Stokes shift indicates bathochromic fluorescence band for both the molecules. The photoluminescence properties of Schiff bases containing electron withdrawing and donating substituents were analyzed. Intramolecular charge transfer behavior can be studied based on the influence of different substituents in Schiff bases. Changes in position and intensity of absorption and fluorescence spectra are responsible for the stabilization of singlet excited-states of Schiff base molecules with different substituents, in polar solvents. This is attributed to the Intramolecular charge transfer (ICT) mechanism. In case of electron donating (-Cl) substituent, ICT contributes largely to positive solvatochromism when compared to electron withdrawing (-NO2) substituent. Ground-state and singlet excited-state dipole moments of NBOA and CBOA were calculated experimentally using solvent polarity function approaches given by Lippert-Mataga, Bakhshiev, Kawskii-Chamma-Viallet and Reichardt. Due to considerable π- electron density redistribution, singlet excited-state dipole moment was found to be greater than ground-state dipole moment. Ground-state dipole moment value which was determined by quantum chemical method was used to estimate excited-state dipole moment using solvatochromic correlations. Kamlet-Abboud-Taft and Catalan multiple linear regression approaches were used to study non-specific solute-solvent interaction and hydrogen bonding interactions in detail. Optimized geometry and HOMO-LUMO energies of NBOA and CBOA have been determined by DFT and TD-DFT/PCM (B3LYP/6-311G (d, p)). Mulliken charges and molecular electrostatic potential have also been evaluated from DFT calculations.
Breakdown of the Bardeen-Cooper-Schrieffer ground state at a quantum phase transtion.
Jaramillo, R.; Feng, Y.; Lang, J. C.; Islam, Z.; Srajer, G.; Littlewood, P. B.; Mc Whan, D. B.; Rosenbaum, T. F.; Univ. of Chicago; Univ. of Cambridge; Massachusetts Innst. of Tech.
2009-05-21
Advances in solid-state and atomic physics are exposing the hidden relationships between conventional and exotic states of quantum matter. Prominent examples include the discovery of exotic superconductivity proximate to conventional spin and charge order, and the crossover from long-range phase order to preformed pairs achieved in gases of cold fermions and inferred for copper oxide superconductors. The unifying theme is that incompatible ground states can be connected by quantum phase transitions. Quantum fluctuations about the transition are manifestations of the competition between qualitatively distinct organizing principles, such as a long-wavelength density wave and a short-coherence-length condensate. They may even give rise to 'protected' phases, like fluctuation-mediated superconductivity that survives only in the vicinity of an antiferromagnetic quantum critical point. However, few model systems that demonstrate continuous quantum phase transitions have been identified, and the complex nature of many systems of interest hinders efforts to more fully understand correlations and fluctuations near a zero-temperature instability. Here we report the suppression of magnetism by hydrostatic pressure in elemental chromium, a simple cubic metal that demonstrates a subtle form of itinerant antiferromagnetism formally equivalent to the Bardeen-Cooper-Schrieffer (BCS) state in conventional superconductors. By directly measuring the associated charge order in a diamond anvil cell at low temperatures, we find a phase transition at pressures of 10 GPa driven by fluctuations that destroy the BCS-like state but preserve the strong magnetic interaction between itinerant electrons and holes. Chromium is unique among stoichiometric magnetic metals studied so far in that the quantum phase transition is continuous, allowing experimental access to the quantum singularity and a direct probe of the competition between conventional and exotic order in a theoretically
Loco, Daniele; Polack, Étienne; Caprasecca, Stefano; Lagardère, Louis; Lipparini, Filippo; Piquemal, Jean-Philip; Mennucci, Benedetta
2016-08-09
A fully polarizable implementation of the hybrid quantum mechanics/molecular mechanics approach is presented, where the classical environment is described through the AMOEBA polarizable force field. A variational formalism, offering a self-consistent relaxation of both the MM induced dipoles and the QM electronic density, is used for ground state energies and extended to electronic excitations in the framework of time-dependent density functional theory combined with a state specific response of the classical part. An application to the calculation of the solvatochromism of the pyridinium N-phenolate betaine dye used to define the solvent ET(30) scale is presented. The results show that the QM/AMOEBA model not only properly describes specific and bulk effects in the ground state but it also correctly responds to the large change in the solute electronic charge distribution upon excitation.
ZHANG Yijun; MENG Qing; LU Weitao; MA Ming; ZHENG Dong; Pau R. Krehbiel
2009-01-01
A new lightning locating technology, called Lightning Mapping Array (LMA), has been developed. The system takes advantage of GPS technology to measure the times of arrival (TOA) of lightning impulsive very high frequency (VHF) radiation events at each remote location. The spatiotemporal development processes of lightning are described in three-dimension by measurement of the system with high time resolution (50 ns) and space precision (50-100 m). The charge structures in thunderstorm and their relationship with lightning discharge processes are revealed. The temporal and spatial characteristics of preliminary breakdown process involved in negative cloud-to-ground (CG) lightning discharges are analyzed based on the data of lightning VHF radiation events. The effect of positive charge region in lower part of thunderstorm on the occurrence of negative CG lightning discharge is discussed. The results indicate that the preliminary breakdown process with longer duration in negative CG lightning discharges is an intracloud discharge process. It occurs between negative and positive charge regions located in middle and lower parts of thunderstorm respectively.It initiates from the negative charge region and propagates downward. After propagating into the positive charge region, the lightning channel develops horizontally. The characteristics of the preliminary breakdown process are consistent with that of intracloud lightning discharges. The stepped leaders are initiated by the K type breakdown which occurs in the last stage of the preliminary breakdown process and develops downward through the positive charge region. The existence of positive charge region in lower part of thunderstorm results in the occurrence of preliminary breakdown process with longer duration before the return stroke of negative CG lightning discharges.
Excited-state charge coupled proton transfer reaction in dipole-functionalized salicylideneaniline
Chen, Kew-Yu, E-mail: kyuchen@fcu.edu.tw; Hu, Jiun-Wei
2015-03-15
Based on design and synthesis of salicylideneaniline derivatives 1–4, we demonstrate an exceedingly useful system to investigate the excited-state intramolecular charge transfer (ESICT) coupled with excited-state intramolecular proton transfer (ESIPT) reaction via the dipolar functionality of Schiff base salicylideneaniline. In solid and aprotic solvents 1–4 exist mainly as E conformers that possess a strong intramolecular six-membered-ring hydrogen bond. Compounds 2–4 exhibit solely a long-wavelength proton-transfer tautomer emission, while dipole-functionalized Schiff base 1 exhibits remarkable dual emission due to the different solvent-polarity environments between ESICT and ESIPT states. Moreover, the geometric structures, frontier molecular orbitals (MOs) and the potential energy curves for 1–4 in the ground and the first singlet excited state were fully rationalized by density functional theory (DFT) and time-dependent DFT calculations. - Highlights: • A dipole-functionalized salicylideneaniline derivative was synthesized. • The Schiff base exhibits remarkable dual emission. • A novel ESICT/ESIPT coupled system was created.
Hermann, Gunter; Liu, ChunMei; Manz, Jörn; Paulus, Beate; Pohl, Vincent; Tremblay, Jean Christophe
2017-09-01
Recently, it was discovered that excitation of the oriented model benzene from its aromatic electronic ground state S0 (1A1g) to the non-aromatic S0 +S2 (1B1u) superposition state generates negative and positive partial charges on alternating carbon atoms. Subsequently, they vary periodically, due to adiabatic attosecond charge migration AACM. Here, we determine the angular electronic flux that mediates this new type of AACM, by means of quantum dynamics simulations. It is found to be periodic, with period τ bar = 590as , and with a pincer motion type pattern such that a total of 1.2 valence electrons flow concertedly between alternating sources and sinks at the carbon nuclei.
Hara, Akito; Awano, Teruyoshi
2017-06-01
Ultrashallow thermal donors (USTDs), which consist of light element impurities such as carbon, hydrogen, and oxygen, have been found in Czochralski silicon (CZ Si) crystals. To the best of our knowledge, these are the shallowest hydrogen-like donors with negative central-cell corrections in Si. We observed the ground-state splitting of USTDs by far-infrared optical absorption at different temperatures. The upper ground-state levels are approximately 4 meV higher than the ground-state levels. This energy level splitting is also consistent with that obtained by thermal excitation from the ground state to the upper ground state. This is direct evidence that the wave function of the USTD ground state is made up of a linear combination of conduction band minimums.
Ground state of the U2Mo compound: Physical properties of the Ω-phase
Losada, E. L.; Garcés, J. E.
2016-10-01
Using ab initio calculations, unexpected structural instability was recently found in the ground state of the U2 Mo compound. Instead of the unstable I4/mmm and the Pmmn structures, in this work the P6/mmm (#191) space group, usually called Ω-phase, is proposed as the fundamental state. Total energy calculations using Wien2k code slightly favoured the last structure. Electronic and elastic properties are studied in this work in order to characterize the physical properties of this new phase. The stability of the Ω-phase is studied by means of its elastic constants calculation and phonon dispersion spectrum. Analysis of isotropic indices shows that the new phase is a ductile material with a minimal degree of anisotropy, suggesting that U2 Mo in the P6/mmm structure is an elastic isotropic material. Analysis of charge density, density of electronic states (DOS) and the character of the bands revealed a high level of hybridization between d-molybdenum electronic states and d- and f-uranium ones.
Charge state studies of low energy heavy ions passing through hydrogen and helium gas
Liu, W; Buchmann, L; Chen, A A; D'Auria, J M; D'Onofrio, A; Engel, S; Gialanella, L; Greife, U; Hunter, D; Hussein, A; Hutcheon, D A; Olin, A; Ottewell, D; Rogalla, D; Rogers, J; Romano, M; Roy, G; Terrasi, F
2003-01-01
Studies of the charge state distribution of low energy (<1.5 MeV/u), low Z (<13) heavy ions passing through hydrogen and helium gas of varying target pressure have been performed using separate windowless gas target systems at TRIUMF and the University of Naples. Semi-empirical relationships have been deduced to estimate the equilibrium charge state distributions as a function of beam energy. From these distributions, cross-sections for the relevant charge changing reactions have been deduced.
Ground-state properties of neutron-rich Mg isotopes
Watanabe, Shin; Shimada, Mitsuhiro; Tagami, Shingo; Kimura, Masaaki; Takechi, Maya; Fukuda, Mitsunori; Nishimura, Daiki; Suzuki, Takeshi; Matsumoto, Takuma; Shimizu, Yoshifumi R; Yahiro, Masanobu
2014-01-01
We analyze recently-measured total reaction cross sections for 24-38Mg isotopes incident on 12C targets at 240 MeV/nucleon by using the folding model and antisymmetrized molecular dynamics(AMD). The folding model well reproduces the measured reaction cross sections, when the projectile densities are evaluated by the deformed Woods-Saxon (def-WS) model with AMD deformation. Matter radii of 24-38Mg are then deduced from the measured reaction cross sections by ?ne-tuning the parameters of the def-WS model. The deduced matter radii are largely enhanced by nuclear deformation. Fully-microscopic AMD calculations with no free parameter well reproduce the deduced matter radii for 24-36Mg, but still considerably underestimate them for 37,38Mg. The large matter radii suggest that 37,38Mg are candidates for deformed halo nucleus. AMD also reproduces other existing measured ground-state properties (spin-parity, total binding energy, and one-neutron separation energy) of Mg isotopes. Neutron-number (N) dependence of defor...
Yang, Chou-Hsun; Hsu, Chao-Ping
2013-10-01
The electron transfer (ET) rate prediction requires the electronic coupling values. The Generalized Mulliken-Hush (GMH) and Fragment Charge Difference (FCD) schemes have been useful approaches to calculate ET coupling from an excited state calculation. In their typical form, both methods use two eigenstates in forming the target charge-localized diabatic states. For problems involve three or four states, a direct generalization is possible, but it is necessary to pick and assign the locally excited or charge-transfer states involved. In this work, we generalize the 3-state scheme for a multi-state FCD without the need of manual pick or assignment for the states. In this scheme, the diabatic states are obtained separately in the charge-transfer or neutral excited subspaces, defined by their eigenvalues in the fragment charge-difference matrix. In each subspace, the Hamiltonians are diagonalized, and there exist off-diagonal Hamiltonian matrix elements between different subspaces, particularly the charge-transfer and neutral excited diabatic states. The ET coupling values are obtained as the corresponding off-diagonal Hamiltonian matrix elements. A similar multi-state GMH scheme can also be developed. We test the new multi-state schemes for the performance in systems that have been studied using more than two states with FCD or GMH. We found that the multi-state approach yields much better charge-localized states in these systems. We further test for the dependence on the number of state included in the calculation of ET couplings. The final coupling values are converged when the number of state included is increased. In one system where experimental value is available, the multi-state FCD coupling value agrees better with the previous experimental result. We found that the multi-state GMH and FCD are useful when the original two-state approach fails.
Yang, Chou-Hsun; Hsu, Chao-Ping
2013-10-21
The electron transfer (ET) rate prediction requires the electronic coupling values. The Generalized Mulliken-Hush (GMH) and Fragment Charge Difference (FCD) schemes have been useful approaches to calculate ET coupling from an excited state calculation. In their typical form, both methods use two eigenstates in forming the target charge-localized diabatic states. For problems involve three or four states, a direct generalization is possible, but it is necessary to pick and assign the locally excited or charge-transfer states involved. In this work, we generalize the 3-state scheme for a multi-state FCD without the need of manual pick or assignment for the states. In this scheme, the diabatic states are obtained separately in the charge-transfer or neutral excited subspaces, defined by their eigenvalues in the fragment charge-difference matrix. In each subspace, the Hamiltonians are diagonalized, and there exist off-diagonal Hamiltonian matrix elements between different subspaces, particularly the charge-transfer and neutral excited diabatic states. The ET coupling values are obtained as the corresponding off-diagonal Hamiltonian matrix elements. A similar multi-state GMH scheme can also be developed. We test the new multi-state schemes for the performance in systems that have been studied using more than two states with FCD or GMH. We found that the multi-state approach yields much better charge-localized states in these systems. We further test for the dependence on the number of state included in the calculation of ET couplings. The final coupling values are converged when the number of state included is increased. In one system where experimental value is available, the multi-state FCD coupling value agrees better with the previous experimental result. We found that the multi-state GMH and FCD are useful when the original two-state approach fails.
Local reversibility and entanglement structure of many-body ground states
Kuwahara, Tomotaka; Amico, Luigi; Vedral, Vlatko
2015-01-01
The low-temperature physics of quantum many-body systems is largely governed by the structure of their ground states. Minimizing the energy of local interactions, ground states often reflect strong properties of locality such as the area law for entanglement entropy and the exponential decay of correlations between spatially separated observables. In this letter we present a novel characterization of locality in quantum states, which we call `local reversibility'. It characterizes the type of operations that are needed to reverse the action of a general disturbance on the state. We prove that unique ground states of gapped local Hamiltonian are locally reversible. This way, we identify new fundamental features of many-body ground states, which cannot be derived from the aforementioned properties. We use local reversibility to distinguish between states enjoying microscopic and macroscopic quantum phenomena. To demonstrate the potential of our approach, we prove specific properties of ground states, which are ...
Ground state properties of a Bose-Einstein condensate confined in an anharmonic external potential
Wang Deng-Long; Yan Xiao-Hong; Tang Yi
2004-01-01
In light of the interference experiment of Bose-Einstein condensates, we present an anharmonic external potential model to study ground state properties of Bose-Einstein condensates. The ground state energy and the chemical potential have been analytically obtained, which are lower than those in harmonic trap. Additionally, it is found that the anharmonic strength of the external potential has an important effect on density and velocity distributions of the ground state for the Thomas-Fermi model.
Upper Bounds on the Degeneracy of the Ground State in Quantum Field Models
Asao Arai
2016-01-01
Full Text Available Axiomatic abstract formulations are presented to derive upper bounds on the degeneracy of the ground state in quantum field models including massless ones. In particular, given is a sufficient condition under which the degeneracy of the ground state of the perturbed Hamiltonian is less than or equal to the degeneracy of the ground state of the unperturbed one. Applications of the abstract theory to models in quantum field theory are outlined.
Exact many-electron ground states on diamond and triangle Hubbard chains
2008-01-01
We construct exact ground states of interacting electrons on triangle and diamond Hubbard chains. The construction requires (i) a rewriting of the Hamiltonian into positive semidefinite form, (ii) the construction of a many-electron ground state of this Hamiltonian, and (iii) the proof of the uniqueness of the ground state. This approach works in any dimension, requires no integrability of the model, and only demands sufficiently many microscopic parameters in the Hamiltonian which have to fu...
Quantum State Transfer between Charge and Flux Qubits in Circuit-QED
WU Qin-Qin; LIAO Jie-Qiao; KUANG Le-Man
2008-01-01
@@ We propose a scheme to implement quantum state transfer in a hybrid circuit quantum electrodynamics (QED)system which consists of a superconducting charge qubit, a flux qubit, and a transmission line resonator (TLR).It is shown that quantum state transfer between the charge qubit and the flux qubit can be realized by using the TLR as the data bus.
Battery Management Systems: Accurate State-of-Charge Indication for Battery-Powered Applications
Pop, V.; Bergveld, H.J.; Danilov, D.; Regtien, P.P.L.; Notten, P.H.L.
2008-01-01
Battery Management Systems – Universal State-of-Charge indication for portable applications describes the field of State-of-Charge (SoC) indication for rechargeable batteries. With the emergence of battery-powered devices with an increasing number of power-hungry features, accurately estimating the
Battery Management Systems: Accurate State-of-Charge Indication for Battery-Powered Applications
Pop, V.; Bergveld, H.J.; Danilov, D.; Regtien, Paulus P.L.; Notten, P.H.L.
2008-01-01
Battery Management Systems – Universal State-of-Charge indication for portable applications describes the field of State-of-Charge (SoC) indication for rechargeable batteries. With the emergence of battery-powered devices with an increasing number of power-hungry features, accurately estimating the
Lower bounds for the ground-state degeneracies of frustrated systems on fractal lattices
Curado; Nobre
2000-12-01
The total number of ground states for nearest-neighbor-interaction Ising systems with frustrations, defined on hierarchical lattices, is investigated. A simple method is presented, which allows one to factorize the ground-state degeneracy, at a given hierarchy level n, in terms of contributions due to all hierarchy levels. Such a method may yield the exact ground-state degeneracy of uniformly frustrated systems, whereas it works as an approximation for randomly frustrated models. In the latter cases, it is demonstrated that such an approximation yields lower-bound estimates for the ground-state degeneracies.
Ground-State Analysis for an Exactly Solvable Coupled-Spin Hamiltonian
Eduardo Mattei
2013-11-01
Full Text Available We introduce a Hamiltonian for two interacting su(2 spins. We use a mean-field analysis and exact Bethe ansatz results to investigate the ground-state properties of the system in the classical limit, defined as the limit of infinite spin (or highest weight. Complementary insights are provided through investigation of the energy gap, ground-state fidelity, and ground-state entanglement, which are numerically computed for particular parameter values. Despite the simplicity of the model, a rich array of ground-state features are uncovered. Finally, we discuss how this model may be seen as an analogue of the exactly solvable p+ip pairing Hamiltonian.
Ground state solutions for asymptotically periodic Schrodinger equations with critical growth
Hui Zhang
2013-10-01
Full Text Available Using the Nehari manifold and the concentration compactness principle, we study the existence of ground state solutions for asymptotically periodic Schrodinger equations with critical growth.
Rosen, Johanna; Anders, Andre; Mraz, Stanislav; Atiser, Adil; Schneider, Jochen M.
2006-03-23
The charge-state-resolved ion energy distributions (IEDs) in filtered aluminum vacuum arc plasmas were measured and analyzed at different oxygen and argon pressures in the range 0.5 8.0 mTorr. A significant reduction of the ion energy was detected as the pressure was increased, most pronounced in an argon environment and for the higher charge states. The corresponding average charge state decreased from 1.87 to 1.0 with increasing pressure. The IEDs of all metal ions in oxygen were fitted with shifted Maxwellian distributions. The results show that it is possible to obtain a plasma composition with a narrow charge-state distribution as well as a narrow IED. These data may enable tailoring thin-film properties through selecting growth conditions that are characterized by predefined charge state and energy distributions.
Spontaneous fission half-lives of heavy nuclei in ground state and in isomeric state
Ren, Zhongzhou; Xu, Chang
2005-09-01
We generalize the formulas of spontaneous fission half-lives of even-even nuclei in their ground state to both the case of odd nuclei and the case of fission isomers [Phys. Rev. C 71 (2005) 014309]. The spontaneous fission half-lives of odd- A nuclei and of odd-odd nuclei in the ground state are calculated by Swiatecki's formula, by its generalized form, and by a new formula where the blocking effect of unpaired nucleon on the half-lives has been taken into account with different mechanisms. By introducing a blocking factor or a generalized seniority in the formulas of the half-lives of even-even nuclei, we can reasonably reproduce the experimental fission half-lives of odd- A nuclei and of odd-odd nuclei with the same parameters used in ground state of even-even nuclei. For spontaneous fission of the isomers in transuranium nuclei the new formula can be simplified into a three-parameter formula and the isomeric half-lives can be well reproduced by the formula. The new formula of the isomeric half-lives is as good as Metag's formula of fission isomers. The half-lives of isomers from these formulas are very accurate and therefore these formulas can give reliable predictions for half-lives of new isomers of neighboring nuclei.
Derivation of novel human ground state naive pluripotent stem cells.
Gafni, Ohad; Weinberger, Leehee; Mansour, Abed AlFatah; Manor, Yair S; Chomsky, Elad; Ben-Yosef, Dalit; Kalma, Yael; Viukov, Sergey; Maza, Itay; Zviran, Asaf; Rais, Yoach; Shipony, Zohar; Mukamel, Zohar; Krupalnik, Vladislav; Zerbib, Mirie; Geula, Shay; Caspi, Inbal; Schneir, Dan; Shwartz, Tamar; Gilad, Shlomit; Amann-Zalcenstein, Daniela; Benjamin, Sima; Amit, Ido; Tanay, Amos; Massarwa, Rada; Novershtern, Noa; Hanna, Jacob H
2013-12-12
Mouse embryonic stem (ES) cells are isolated from the inner cell mass of blastocysts, and can be preserved in vitro in a naive inner-cell-mass-like configuration by providing exogenous stimulation with leukaemia inhibitory factor (LIF) and small molecule inhibition of ERK1/ERK2 and GSK3β signalling (termed 2i/LIF conditions). Hallmarks of naive pluripotency include driving Oct4 (also known as Pou5f1) transcription by its distal enhancer, retaining a pre-inactivation X chromosome state, and global reduction in DNA methylation and in H3K27me3 repressive chromatin mark deposition on developmental regulatory gene promoters. Upon withdrawal of 2i/LIF, naive mouse ES cells can drift towards a primed pluripotent state resembling that of the post-implantation epiblast. Although human ES cells share several molecular features with naive mouse ES cells, they also share a variety of epigenetic properties with primed murine epiblast stem cells (EpiSCs). These include predominant use of the proximal enhancer element to maintain OCT4 expression, pronounced tendency for X chromosome inactivation in most female human ES cells, increase in DNA methylation and prominent deposition of H3K27me3 and bivalent domain acquisition on lineage regulatory genes. The feasibility of establishing human ground state naive pluripotency in vitro with equivalent molecular and functional features to those characterized in mouse ES cells remains to be defined. Here we establish defined conditions that facilitate the derivation of genetically unmodified human naive pluripotent stem cells from already established primed human ES cells, from somatic cells through induced pluripotent stem (iPS) cell reprogramming or directly from blastocysts. The novel naive pluripotent cells validated herein retain molecular characteristics and functional properties that are highly similar to mouse naive ES cells, and distinct from conventional primed human pluripotent cells. This includes competence in the generation
1984-07-27
M81757/8-2, 20Ah Battery . ............ o.......... o..........o.................... 40 8B Charge Temperature Chart for Type M81757/8-2, 20-Ah Battery . 41... battery M83769/ 6-1. M83769/7-1 12V , 54 Ah 6140-00-328-3854 C-117D, C-118B, VC-1118B, C- 131F, T-33B Varley 24V, 18 Ah 6140-00-467-6112 AV-8A, AV-8C...RD-A144 243 EVALUATION OF AIRCRAFT BATTERY CHARGE DISCHARGE AND i/i ANKLYZAT ION REQUIREME. U) NAVAL WEAPONS SUPPORT CENTER CRANE IN WEAPONS QUALITY
E2 transitions between excited single-phonon states: Role of ground-state correlations
Kamerdzhiev, S. P. [National Research Centre Kurchatov Institute (Russian Federation); Voitenkov, D. A., E-mail: dvoytenkov@ippe.ru [Institute for Physics and Power Engineering (Russian Federation)
2016-11-15
The probabilities for E2 transitions between low-lying excited 3{sup −} and 5{sup −} single-phonon states in the {sup 208}Pb and {sup 132}Sn magic nuclei are estimated on the basis of the theory of finite Fermi systems. The approach used involves a new type of ground-state correlations, that which originates from integration of three (rather than two, as in the random-phase approximation) single-particle Green’s functions. These correlations are shown to make a significant contribution to the probabilities for the aforementioned transitions.
Jia, Dongming; Manz, Jörn; Paulus, Beate; Pohl, Vincent; Tremblay, Jean Christophe; Yang, Yonggang
2017-01-01
We design four linearly x- and y-polarized as well as circularly right (+) and left (-) polarized, resonant π / 2 -laser pulses that prepare the model benzene molecule in four different degenerate superposition states. These consist of equal (0.5) populations of the electronic ground state S0 (1A1g) plus one of four degenerate excited states, all of them accessible by dipole-allowed transitions. Specifically, for the molecule aligned in the xy-plane, these excited states include different complex-valued linear combinations of the 1E1u,x and 1E1u,y degenerate states. As a consequence, the laser pulses induce four different types of periodic adiabatic attosecond (as) charge migrations (AACM) in benzene, all with the same period, 504 as, but with four different types of angular fluxes. One of the characteristic differences of these fluxes are the two angles for zero fluxes, which appear as the instantaneous angular positions of the "source" and "sink" of two equivalent, or nearly equivalent branches of the fluxes which flow in pincer-type patterns from one molecular site (the "source") to the opposite one (the "sink"). These angles of zero fluxes are either fixed at the positions of two opposite carbon nuclei in the yz-symmetry plane, or at the centers of two opposite carbon-carbon bonds in the xz-symmetry plane, or the angles of zero fluxes rotate in angular forward (+) or backward (-) directions, respectively. As a resume, our quantum model simulations demonstrate quantum control of the electronic fluxes during AACM in degenerate superposition states, in the attosecond time domain, with the laser polarization as the key knob for control.
Characterizing topological order by studying the ground States on an infinite cylinder.
Cincio, L; Vidal, G
2013-02-08
Given a microscopic lattice Hamiltonian for a topologically ordered phase, we propose a numerical approach to characterize its emergent anyon model and, in a chiral phase, also its gapless edge theory. First, a tensor network representation of a complete, orthonormal set of ground states on a cylinder of infinite length and finite width is obtained through numerical optimization. Each of these ground states is argued to have a different anyonic flux threading through the cylinder. Then a quasiorthogonal basis on the torus is produced by chopping off and reconnecting the tensor network representation on the cylinder. From these two bases, and by using a number of previous results, most notably the recent proposal of Y. Zhang et al. [Phys. Rev. B 85, 235151 (2012)] to extract the modular U and S matrices, we obtain (i) a complete list of anyon types i, together with (ii) their quantum dimensions d(i) and total quantum dimension D, (iii) their fusion rules N(ij)(k), (iv) their mutual statistics, as encoded in the off-diagonal entries S(ij) of S, (v) their self-statistics or topological spins θ(i), (vi) the topological central charge c of the anyon model, and, in a chiral phase (vii) the low energy spectrum of each sector of the boundary conformal field theory. As a concrete application, we study the hard-core boson Haldane model by using the two-dimensional density matrix renormalization group. A thorough characterization of its universal bulk and edge properties unambiguously shows that it realizes a ν=1/2 bosonic fractional quantum Hall state.
Saraf, Shailendhar; Buchman, Sasha; Balakrishnan, Karthik; Lui, Chin Yang; Soulage, Michael; Faied, Dohy; Hanson, John; Ling, Kuok; Jaroux, Belgacem; Suwaidan, Badr Al; AlRashed, Abdullah; Al-Nassban, Badr; Alaqeel, Faisal; Harbi, Mohammed Al; Salamah, Badr Bin; Othman, Mohammed Bin; Qasim, Bandar Bin; Alfauwaz, Abdulrahman; Al-Majed, Mohammed; DeBra, Daniel; Byer, Robert
2016-12-01
The UV-LED mission demonstrates the precise control of the potential of electrically isolated test masses. Test mass charge control is essential for the operation of space accelerometers and drag-free sensors which are at the core of geodesy, aeronomy and precision navigation missions as well as gravitational wave experiments and observatories. Charge management using photoelectrons generated by the 254 nm UV line of Hg was first demonstrated on Gravity Probe B and is presently part of the LISA Pathfinder technology demonstration. The UV-LED mission and prior ground testing demonstrates that AlGaN UVLEDs operating at 255 nm are superior to Hg lamps because of their smaller size, lower power draw, higher dynamic range, and higher control authority. We show laboratory data demonstrating the effectiveness and survivability of the UV-LED devices and performance of the charge management system. We also show flight data from a small satellite experiment that was one of the payloads on KACST’s SaudiSat-4 mission that demonstrates ‘AC charge control’ (UV-LEDs and bias are AC modulated with adjustable relative phase) between a spherical test mass and its housing. The result of the mission brings the UV-LED device Technology Readiness Level (TRL) to TRL-9 and the charge management system to TRL-7. We demonstrate the ability to control the test mass potential on an 89 mm diameter spherical test mass over a 20 mm gap in a drag-free system configuration, with potential measured using an ultra-high impedance contact probe. Finally, the key electrical and optical characteristics of the UV-LEDs showed less than 7.5% change in performance after 12 months in orbit.
Determination of the Ionic Charge States of SEPs Using the University of Chicago IMP-8 Instrument
Dietrich, W.
We use a new method to calculate the mean ionization charge state of solar energetic particles (SEPs) observed with the University of Chicago Cosmic Ray Nuclear Composition experiment on the IMP-8 satellite. The method, using the time to maximum flux, is demonstrated for several gradual SEP events, including the events on 29 September 1989, 19 October 1989, 24 October 1989, and 6 November 1997. Mean ionic charge states are deduced for heavy ions with energies in the range ~10- 500 MeV/nucleon. The ionic charge determination is made only during the onset of the SEP events. These mean charge states agree well with previous measurements for SEP events both at low energy (~0.5-4 MeV/nucleon reported by ISEE-3) and at higher energies (~200-500 MeV/nucleon reported by LDEF). The mean ionic charge states are then used to determine an average temperature and source region for these particles.
Recoil ion charge state distributions in low energy Ar{sup q+} {minus} Ar collisions
Vancura, J.; Marchetti, V.; Kostroun, V.O.
1992-12-31
We have measured the recoil ion charge state distributions in Ar{sup q+} -- Ar (8{le}q{le}16) collisions at 2.3 qkeV and 0.18qkeV by time of flight (TOF) spectroscopy. For Ar{sup 8-16+}, recoil ion charge states up to 6+ are clearly present, indicating that the 3p subshell in the target atom is being depleted, while for Ar{sup 10-16+}, there is evidence that target 3s electrons are also being removed. Comparison of the recoil ion charge state spectra at 2.3 and 0.18 qkeV shows that for a given projectile charge, there is very little dependence of the observed recoil target charge state distribution on projectile energy.
Ground State of a Two-Electron Quantum Dot with a Gaussian Confining Potential
XIE Wen-Fang
2006-01-01
We investigate the ground-state properties of a two-dimensional two-electron quantum dot with a Gaussian confining potential under the influence of perpendicular homogeneous magnetic field. Calculations are carried out by using the method of numerical diagonalization of Hamiltonian matrix within the effective-mass approximation. A ground-state behaviour (singlet→triplet state transitions) as a function of the strength of a magnetic field has been found. It is found that the dot radius R of the Gaussian potential is important for the ground-state transition and the feature of ground-state for the Gaussian potential quantum dot (QD), and the parabolic potential QDs are similar when R is larger. The larger the quantum dot radius, the smaller the magnetic field for the singlet-triplet transition of the ground-state of two interacting electrons in the Gaussian quantum dot.
Lu, Xiaonan; Sun, Kai; Guerrero, Josep M.
2014-01-01
In this paper, a droop control based state-of-charge (SoC) balancing method in autonomous DC microgrids is proposed. Both charging and discharging process have been considered. In particular, in the charging process, the droop coefficient is set to be proportional to SoCn, and in the discharging...... process, the droop coefficient is set to be inversely proportional to SoCn. Since the injected/output power is in inverse-proportion to the droop coefficient, with the proposed method, the energy storage unit (ESU) with higher SoC absorbs less power in the charging process and delivers more power...... in the discharging process. Meanwhile, the ESU with lower SoC absorbs more power in the charging process and delivers less power in the discharging process. Eventually, the SoC and injected/output power in each ESU are equalized. The exponent n for SoC is employed to regulate the balancing speed of the So...
Ground-state and excited-state structures of tungsten-benzylidyne complexes
Lovaasen, B. M.; Lockard, J. V.; Cohen, B. W.; Yang, S.; Zhang, X.; Simpson, C. K.; Chen, L. X.; Hopkins, M. D. (Chemical Sciences and Engineering Division); ( XSD); (The Univ. of Chicago)
2012-01-01
The molecular structure of the tungsten-benzylidyne complex trans-W({triple_bond}CPh)(dppe){sub 2}Cl (1; dppe = 1,2-bis(diphenylphosphino)ethane) in the singlet (d{sub xy}){sup 2} ground state and luminescent triplet (d{sub xy}){sup 1}({pi}*(WCPh)){sup 1} excited state (1*) has been studied using X-ray transient absorption spectroscopy, X-ray crystallography, and density functional theory (DFT) calculations. Molecular-orbital considerations suggest that the W-C and W-P bond lengths should increase in the excited state because of the reduction of the formal W-C bond order and decrease in W {yields} P {pi}-backbonding, respectively, between 1 and 1*. This latter conclusion is supported by comparisons among the W-P bond lengths obtained from the X-ray crystal structures of 1, (d{sub xy}){sup 1}-configured 1{sup +}, and (d{sub xy}){sup 2} [W(CPh)(dppe){sub 2}(NCMe)]{sup +} (2{sup +}). X-ray transient absorption spectroscopic measurements of the excited-state structure of 1* reveal that the W-C bond length is the same (within experimental error) as that determined by X-ray crystallography for the ground state 1, while the average W-P/W-Cl distance increases by 0.04 {angstrom} in the excited state. The small excited-state elongation of the W-C bond relative to the M-E distortions found for M({triple_bond}E)L{sub n} (E = O, N) compounds with analogous (d{sub xy}){sup 1}({pi}*(ME)){sup 1} excited states is due to the {pi} conjugation within the WCPh unit, which lessens the local W-C {pi}-antibonding character of the {pi}*(WCPh) lowest unoccupied molecular orbital (LUMO). These conclusions are supported by DFT calculations on 1 and 1*. The similar core bond distances of 1, 1{sup +}, and 1* indicates that the inner-sphere reorganization energy associated with ground- and excited-state electron-transfer reactions is small.
Search for charged Higgs bosons using other final states
Sandoval Usme, Carlos; The ATLAS collaboration
2014-01-01
Three different searches for charged Higgs bosons with the ATLAS detector were presented. First, a search for a charged Higgs boson in t ¯t decays was presented, where one of the top quarks decays via t → H+b, followed by H+ → c ¯ s [1]. 95 % confidence level (CL) upper limits on B(t → bH+) varying between 5 % and 1 % for H+ masses between 90 GeV and 150 GeV, assuming B(H+ →c ¯ s) = 100% were presented. This was followed by the presentation of a search for charged Higgs bosons through the violation of lepton universality in t ¯t events, were signatures containing leptons (e/m) and/or a hadronically decaying t (thad) were used [2]. No significant deviation from the Standard Model predictions was observed. With the assumption that the branching fraction B(H+→tn ) is 100%, upper limits in the range 3.2% to 4.4% on the branching fraction B(t →bH+) for charged Higgs boson masses in the range 90−140 GeV were presented. Finally, a search for new particles in an extension to the Standard Model that ...
Charge fluctuations in a final state with QGP
Fialkowski, K.; Wit, R. de
2001-01-01
Charge fluctuations as a possible signal of quark - gluon plasma (QGP) were recently suggested. A short summary of comments presented on this subject is given and supplemented by a discussion of the coexistence of pions produced "directly" and through a QGP phase. Such a coexistence may obscure the expected plasma signal similarly to the effects considered in the comments mentioned above.
Improved solid state electron-charge-storage device
Kuper, A. B.
1970-01-01
Storage device is applicable in memory systems and in high-resolution arrays for light-responsive image sensing. The device offers high yield in multiple arrays and allows charge release with light striking only the edge of a metal electrode.
The influence of the beam charge state on the analytical calculation of RBS and ERDA spectra
Barradas, Nuno P., E-mail: nunoni@ctn.ist.utl.pt [Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, E.N. 10 ao km 139,7, 2695-066 Bobadela LRS (Portugal); Kosmata, Marcel [Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01328 Dresden (Germany); Globalfoundries, Wilschdorfer Landstraße 101, 01109 Dresden (Germany); Hanf, Daniel; Munnik, Frans [Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01328 Dresden (Germany)
2016-03-15
Analytical codes dedicated to the analysis of Ion Beam Analysis data rely on the accuracy of both the calculations and of basic data such as scattering cross sections and stopping powers. So far, the effect of the beam charge state of the incoming beam has been disregard by general purpose analytical codes such as NDF. In fact, the codes implicitly assume that the beam always has the equilibrium charge state distribution, by using tabulated stopping power values e.g. from SRIM, which are in principle valid for the effective charge state. The dependence of the stopping power with the changing charge state distribution is ignored. This assumption is reasonable in most cases, but for high resolution studies the actual change of the charge state distribution from the initial beam charge state towards equilibrium as it enters and traverses the sample must be taken into account, as it influences the shape of the observed data. In this work, we present an analytical calculation, implemented in NDF, that takes this effect into account. For elastic recoil detection analysis (ERDA), the changing charge state distribution of the recoils can also be taken into account. We apply the calculation to the analysis of experimental high depth resolution ERDA data for various oxide layers collected using a magnetic spectrometer.
Revised Iterative Solution of Ground State of Double-Well Potential
ZHAO Wei-Qin
2005-01-01
The revised new iterative method for solving the ground state of Schrodinger equation is deduced. Based on Green functions defined by quadratures along a single trajectory this iterative method is applied to solve the ground state of the double-well potential. The result is compared to the one based on the original iterative method. The limitation of the asymptotic expansion is also discussed.
Ground state solutions for nonlinear fractional Schrodinger equations involving critical growth
Hua Jin
2017-03-01
Full Text Available This article concerns the ground state solutions of nonlinear fractional Schrodinger equations involving critical growth. We obtain the existence of ground state solutions when the potential is not a constant and not radial. We do not use the Ambrosetti-Rabinowitz condition, or the monotonicity condition on the nonlinearity.
Ground state correlations and mean field using the exp(S) method
Heisenberg, J H; Heisenberg, Jochen H.; Mihaila, Bogdan
1999-01-01
This document gives a detailed account of the terms used in the computation of the ground state mean field and the ground state correlations. While the general approach to this description is given in a separate paper (nucl-th/9802029) we give here the explicite expressions used.
The study of magnetization of the spin systm in the ground state
Jiang Wei; Wang Xi-Kun; Zhao Qiang
2006-01-01
Within the framework of the effective-field theory with self-spin correlations and the differential operator technique,the ground state magnetizations of the biaxial crystal field spin system on the honeycomb lattices have been studied.The influences of the biaxial crystal field on the magnetization in the ground state have been investigated in detail.
Improved lower bounds on the ground-state entropy of the antiferromagnetic Potts model.
Chang, Shu-Chiuan; Shrock, Robert
2015-05-01
We present generalized methods for calculating lower bounds on the ground-state entropy per site, S(0), or equivalently, the ground-state degeneracy per site, W=e(S(0)/k(B)), of the antiferromagnetic Potts model. We use these methods to derive improved lower bounds on W for several lattices.
Parniak, Michał; Wasilewski, Wojciech
2015-01-01
We demonstrate an interface between light coupled to transition between excited states of rubidium and long-lived ground-state atomic coherence. In our proof-of-principle experiment a non-linear process of four-wave mixing in an open-loop configuration is used to achieve light emission proportional to independently prepared ground-state atomic coherence. We demonstrate strong correlations between Raman light heralding generation of ground-state coherence and the new four-wave mixing signal. Dependance of the efficiency of the process on laser detunings is studied.
Theory for charge states of energetic oxygen ions in the earth's radiation belts
Spjeldvik, W. N.; Fritz, T. A.
1978-01-01
Fluxes of geomagnetically trapped energetic oxygen ions have been studied in detail. Ion distributions in radial locations below the geostationary orbit, energy spectra between 1 keV and 100 MeV, and the distribution over charge states have been computed for equatorially mirroring ions. Both ionospheric and solar wind oxygen ion sources have been considered, and it is found that the charge state distributions in the interior of the radiation belts are largely independent of the charge state characteristics of the sources. In the MeV range, oxygen ions prove to be a more sensitive probe for radiation belt dynamics than helium ions and protons.
Guan, Zhiqiang; Li, Ho-Wa; Zhang, Jinfeng; Cheng, Yuanhang; Yang, Qingdan; Lo, Ming-Fai; Ng, Tsz-Wai; Tsang, Sai-Wing; Lee, Chun-Sing
2016-08-24
How charge-transfer states (CTSs) assist charge separation of a Coulombically bound exciton in organic photovoltaics has been a hot topic. It is believed that the delocalization feature of a CTS plays a crucial role in the charge separation process. However, the delocalization of the "hot" and the "relaxed" CTSs is still under debate. Here, with a novel frequency dependent charge-modulated electroabsorption spectroscopy (CMEAS) technique, we elucidate clearly that both "hot" and "relaxed" CTSs are loosely bound and delocalized states. This is confirmed by comparing the CMEAS results of CTSs with those of localized polaron states. Our results reveal the role of CTS delocalization on charge separation and indicate that no substantial delocalization gradient exists in CTSs.
Geometry of non-supersymmetric three-charge bound states
Gimon, Eric; Gimon, Eric G.; Levi, Thomas S.; Ross, Simon F.
2007-05-14
We study the smooth non-supersymmetric three-charge microstatesof Jejjala, Madden, Ross and Titchener using Kaluza-Klein reductions of the solutions to five and four dimensions. Our aim is to improve our understanding of the relation between these non-supersymmetric solutions and the well-studied supersymmetric cases. We find some surprising qualitative differences. In the five-dimensional description, the solution has orbifold fixed points which break supersymmetry locally, so the geometries cannot be thought of as made up of separate half-BPS centers. In the four-dimensional description, the two singularities in the geometry are connected by a conical singularity, which makes it impossible to treat them independently and assign unambiguous brane charges to these centers.
Pattengale, Brian; Yang, Sizhuo; Ludwig, John; Huang, Zhuangqun; Zhang, Xiaoyi; Huang, Jier
2016-07-06
Zeolitic Imidazolate Frameworks (ZIFs) have emerged as a novel class of porous metal-organic frameworks (MOFs) for catalysis application because of their exceptional thermal and chemical stability. Inspired by the broad absorption of ZIF-67 in UV-visible-near IR region, we explored its excited state and charge separation dynamics, properties essential for photocatalytic applications, using optical (OTA) and X-ray transient absorption (XTA) spectroscopy. OTA results show that an exceptionally long-lived excited state is formed after photoexcitation. This long-lived excited state was confirmed to be the charge separated state with ligandto-metal charge transfer character using XTA. The surprisingly long-lived charge separated state, together with its intrinsic hybrid nature, all point to its potential application in heterogeneous photocatalysis and energy conversion.
Theoretical Study of the Charge-Transfer State Separation within Marcus Theory
Volpi, Riccardo; Nassau, Racine; Nørby, Morten Steen
2016-01-01
We study, within Marcus theory, the possibility of the charge-transfer (CT) state splitting at organic interfaces and a subsequent transport of the free charge carriers to the electrodes. As a case study we analyze model anthracene-C60 interfaces. Kinetic Monte Carlo (KMC) simulations on the cold...
Measuring the charge state of an adatom with noncontact atomic force microscopy
Gross, L.; Mohn, F.; Liljeroth, P.; Repp, J.; Meyer, G.; Giessibl, F.J.
2009-01-01
Charge states of atoms can be investigated with scanning tunneling microscopy, but this method requires a conducting substrate. We investigated the charge-switching of individual adsorbed gold and silver atoms (adatoms) on ultrathin NaCl films on Cu(111) using a qPlus tuning fork atomic force micros
Stevenson, I C; Chen, Y P; Elliott, D S
2016-01-01
We report a newly observed photoassociation resonance in $^7$Li-$^{85}$Rb, a mixed $2(1) - 4(1)$ excited state, that spontaneously decays to the rovibronic ground state. This resonance between ultracold Li and Rb is the strongest ground state molecule-forming photoassociation line observed in LiRb, and forms deeply bound $X \\: ^1\\Sigma^+$ molecules in large numbers. The production rate of the $v=0 \\ J=0$ rovibrational ground state is $\\sim 1.5 \\times 10^{4}$ molecules/s.
The significant role of covalency in determining the ground state of cobalt phthalocyanines molecule
Jing Zhou
2016-03-01
Full Text Available To shed some light on the metal 3d ground state configuration of cobalt phthalocyanines system, so far in debate, we present an investigation by X-ray absorption spectroscopy (XAS at Co L2,3 edge and theoretical calculation. The density functional theory calculations reveal highly anisotropic covalent bond between central cobalt ion and nitrogen ligands, with the dominant σ donor accompanied by weak π-back acceptor interaction. Our combined experimental and theoretical study on the Co-L2,3 XAS spectra demonstrate a robust ground state of 2A1g symmetry that is built from 73% 3d7 character and 27% 3 d 8 L ¯ ( L ¯ denotes a ligand hole components, as the first excited-state with 2Eg symmetry lies about 158 meV higher in energy. The effect of anisotropic and isotropic covalency on the ground state was also calculated and the results indicate that the ground state with 2A1g symmetry is robust in a large range of anisotropic covalent strength while a transition of ground state from 2A1g to 2Eg configuration when isotropic covalent strength increases to a certain extent. Here, we address a significant anisotropic covalent effect of short Co(II-N bond on the ground state and suggest that it should be taken into account in determining the ground state of analogous cobalt complexes.
Ground-state Properties of Inhomogeneous Graphene Sheets
Polini, Marco
2009-03-01
When inter-valley scattering is weak and gauge fields due to e.g. ripples are neglected, doped and gated graphene sheets can be described using an envelope-function Hamiltonian with a new sublattice pseudospin degree-of freedom, an ultrarelativistic massless-Dirac free-fermion term, a pseudospin scalar disorder potential, and a non-relativistic instantaneous Coulombic interaction term. There is considerable evidence from experiment that this simplified description of a honeycomb lattice of Carbon atoms is usually a valid starting point for theories of those observables that depend solely on the electronic properties of π-electrons near the graphene Dirac point [1]. Although the use of this model simplifies the physics considerably it still leaves us with a many-body problem without translational invariance, which we do not know how to solve. In this talk we present a Kohn-Sham-Dirac density-functional-theory (DFT) scheme for graphene sheets that treats slowly-varying inhomogeneous scalar external potentials and electron-electron interactions on an equal footing [2]. The theory is able to account for the unusual property that the exchange-correlation contribution to chemical potential increases with carrier density in graphene [3,4]. Consequences of this property, and advantages and disadvantages of using the DFT approach to describe it, are discussed. The approach is illustrated by solving the Kohn-Sham-Dirac equations self-consistently for a model random potential describing charged point-like impurities located close to the graphene plane. The influence of electron-electron interactions on these non-linear screening calculations is discussed at length, in the light of recent experiments [5,6] reporting evidence for the presence of electron-hole puddles in nearly-neutral graphene sheets. [4pt] [1] A.K. Geim and K.S. Novoselov, Nature Mater. 6, 183 (2007); A.K. Geim and A.H. MacDonald, Phys. Today 60, 35 (2007); A.H. Castro Neto, F. Guinea, N.M.R. Peres, K
Charge states and lattice sites of dilute implanted Sn in ZnO
Mølholt, T. E.; Gunnlaugsson, H. P.; Johnston, K.; Mantovan, R.; Röder, J.; Adoons, V.; Mokhles Gerami, A.; Masenda, H.; Matveyev, Y. A.; Ncube, M.; Unzueta, I.; Bharuth-Ram, K.; Gislason, H. P.; Krastev, P.; Langouche, G.; Naidoo, D.; Ólafsson, S.; Zenkevich, A.; ISOLDE Collaboration
2017-04-01
The common charge states of Sn are 2+ and 4+. While charge neutrality considerations favour 2+ to be the natural charge state of Sn in ZnO, there are several reports suggesting the 4+ state instead. In order to investigate the charge states, lattice sites, and the effect of the ion implantation process of dilute Sn atoms in ZnO, we have performed 119Sn emission Mössbauer spectroscopy on ZnO single crystal samples following ion implantation of radioactive 119In (T ½ = 2.4 min) at temperatures between 96 K and 762 K. Complementary perturbed angular correlation measurements on 111mCd implanted ZnO were also conducted. Our results show that the 2+ state is the natural charge state for Sn in defect free ZnO and that the 4+ charge state is stabilized by acceptor defects created in the implantation process.
High ion charge states in a high-current, short-pulse, vacuum ARC ion sources
Anders, A.; Brown, I.; MacGill, R.; Dickinson, M. [Lawrence Berkeley National Lab., CA (United States)
1996-08-01
Ions of the cathode material are formed at vacuum arc cathode spots and extracted by a grid system. The ion charge states (typically 1-4) depend on the cathode material and only little on the discharge current as long as the current is low. Here the authors report on experiments with short pulses (several {mu}s) and high currents (several kA); this regime of operation is thus approaching a more vacuum spark-like regime. Mean ion charge states of up to 6.2 for tungsten and 3.7 for titanium have been measured, with the corresponding maximum charge states of up to 8+ and 6+, respectively. The results are discussed in terms of Saha calculations and freezing of the charge state distribution.
Aslam, N; Neumann, P; Jelezko, F; Wrachtrup, J
2012-01-01
The nitrogen-vacancy centre (NV) has drawn much attention for over a decade, yet detailed knowledge of the photophysics needs to be established. Under typical conditions, the NV can have two stable charge states, negative (NV-) or neutral (NV0), with photo induced interconversion of these two states. Here, we present detailed studies of the ionization dynamics of single NV centres in bulk diamond at room temperature during illumination in dependence of the excitation wavelength and power. We apply a recent method which allows us to directly measure the charge state of a single NV centre, and observe its temporal evolution. Results of this work are the steady state NV- population, which was found to be always < 75% for 450 to 610 nm excitation wavelength, the relative absorption cross-section of NV- for 540 to 610 nm, and the energy of the NV- ground state of 2.6 eV below the conduction band. These results will help to further understand the photo-physics of the NV centre.
Charge states of energetic solar particles. Die Ladungszustaende solarer energetischer Teilchen
Luhn, A.M.
1985-01-01
The dissertation deals with the measurement and interpretation of the charge state of energetic solar particles. Measurements of the C, N, O, Ne, Mg, Si, S and Fe ions were carried out with the ULEZEQ sensor on the ISEE-3 satellite. For the first time it was possible to determine the three parameters energy, atomic number and charge state of infalling ions separately and indepedent from each other.
Recoil ion charge state distribution following the beta(sup +) decay of {sup 21}Na
Scielzo, Nicholas D.; Freedman, Stuart J.; Fujikawa, Brian K.; Vetter, Paul A.
2003-01-03
The charge state distribution following the positron decay of 21Na has been measured, with a larger than expected fraction of the daughter 21Ne in positive charge states. No dependence on either the positron or recoil nucleus energy is observed. The data is compared to a simple model based on the sudden approximation. Calculations suggest a small but important contribution from recoil ionization has important consequences for precision beta decay correlation experiments detecting recoil ions.
Recoil ion charge state distribution following the beta(sup +) decay of {sup 21}Na
Scielzo, Nicholas D.; Freedman, Stuart J.; Fujikawa, Brian K.; Vetter, Paul A.
2003-01-03
The charge state distribution following the positron decay of 21Na has been measured, with a larger than expected fraction of the daughter 21Ne in positive charge states. No dependence on either the positron or recoil nucleus energy is observed. The data is compared to a simple model based on the sudden approximation. Calculations suggest a small but important contribution from recoil ionization has important consequences for precision beta decay correlation experiments detecting recoil ions.
ARCHITECTURE OF A CHARGE-TRANSFER STATE REGULATING LIGHT HARVESTING IN A PLANT ANTENNA PROTEIN
Fleming, Graham; Ahn, Tae Kyu; Avenson, Thomas J.; Ballottari, Matteo; Cheng, Yuan-Chung; Niyogi, Krishna K.; Bassi, Roberto; Fleming, Graham R.
2008-04-02
Energy-dependent quenching of excess absorbed light energy (qE) is a vital mechanism for regulating photosynthetic light harvesting in higher plants. All of the physiological characteristics of qE have been positively correlated with charge-transfer between coupled chlorophyll and zeaxanthin molecules in the light-harvesting antenna of photosystem II (PSII). In this work, we present evidence for charge-transfer quenching in all three of the individual minor antenna complexes of PSII (CP29, CP26, and CP24), and we conclude that charge-transfer quenching in CP29 involves a de-localized state of an excitonically coupled chlorophyll dimer. We propose that reversible conformational changes in CP29 can `tune? the electronic coupling between the chlorophylls in this dimer, thereby modulating the energy of the chlorophylls-zeaxanthin charge-transfer state and switching on and off the charge-transfer quenching during qE.
Charge-state-dependent energy loss of slow ions. II. Statistical atom model
Wilhelm, Richard A.; Möller, Wolfhard
2016-05-01
A model for charge-dependent energy loss of slow ions is developed based on the Thomas-Fermi statistical model of atoms. Using a modified electrostatic potential which takes the ionic charge into account, nuclear and electronic energy transfers are calculated, the latter by an extension of the Firsov model. To evaluate the importance of multiple collisions even in nanometer-thick target materials we use the charge-state-dependent potentials in a Monte Carlo simulation in the binary collision approximation and compare the results to experiment. The Monte Carlo results reproduce the incident charge-state dependence of measured data well [see R. A. Wilhelm et al., Phys. Rev. A 93, 052708 (2016), 10.1103/PhysRevA.93.052708], even though the experimentally observed charge exchange dependence is not included in the model.
Architecture of a charge-transfer state regulating light harvesting in a plant antenna protein.
Ahn, Tae Kyu; Avenson, Thomas J; Ballottari, Matteo; Cheng, Yuan-Chung; Niyogi, Krishna K; Bassi, Roberto; Fleming, Graham R
2008-05-01
Energy-dependent quenching of excess absorbed light energy (qE) is a vital mechanism for regulating photosynthetic light harvesting in higher plants. All of the physiological characteristics of qE have been positively correlated with charge transfer between coupled chlorophyll and zeaxanthin molecules in the light-harvesting antenna of photosystem II (PSII). We found evidence for charge-transfer quenching in all three of the individual minor antenna complexes of PSII (CP29, CP26, and CP24), and we conclude that charge-transfer quenching in CP29 involves a delocalized state of an excitonically coupled chlorophyll dimer. We propose that reversible conformational changes in CP29 can "tune" the electronic coupling between the chlorophylls in this dimer, thereby modulating the energy of the chlorophyll-zeaxanthin charge-transfer state and switching on and off the charge-transfer quenching during qE.
Ground-state characterizations of systems predicted to exhibit L11 or L13 crystal structures
Nelson, Lance J.; Hart, Gus L. W.; Curtarolo, Stefano
2012-02-01
Despite their geometric simplicity, the crystal structures L11 (CuPt) and L13 (CdPt3) do not appear as ground states experimentally, except in Cu-Pt. We investigate the possibility that these phases are ground states in other binary intermetallic systems, but overlooked experimentally. Via the synergy between high-throughput and cluster-expansion computational methods, we conduct a thorough search for systems that may exhibit these phases and calculate order-disorder transition temperatures when they are predicted. High-throughput calculations predict L11 ground states in the systems Ag-Pd, Ag-Pt, Cu-Pt, Pd-Pt, Li-Pd, Li-Pt, and L13 ground states in the systems Cd-Pt, Cu-Pt, Pd-Pt, Li-Pd, Li-Pt. Cluster expansions confirm the appearance of these ground states in some cases. In the other cases, cluster expansion predicts unsuspected derivative superstructures as ground states. The order-disorder transition temperatures for all L11/L13 ground states were found to be sufficiently high that their physical manifestation may be possible.
Exact spin-cluster ground states in a mixed diamond chain
Takano, Ken'Ichi; Suzuki, Hidenori; Hida, Kazuo
2009-09-01
The mixed diamond chain is a frustrated Heisenberg chain composed of successive diamond-shaped units with two kinds of spins of magnitudes S and S/2 ( S : integer). Ratio λ of two exchange parameters controls the strength of frustration. With varying λ , the Haldane state and several spin-cluster states appear as the ground state. A spin-cluster state is a tensor product of exact local eigenstates of cluster spins. We prove that a spin-cluster state is the ground state in a finite interval of λ . For S=1 , we numerically determine the total phase diagram consisting of five phases.
Santhosh, K.P., E-mail: drkpsanthosh@gmail.co [School of Pure and Applied Physics, Kannur University, Payyanur Campus, Payyanur 670 327 (India); Sahadevan, Sabina; Joseph, Jayesh George [School of Pure and Applied Physics, Kannur University, Payyanur Campus, Payyanur 670 327 (India)
2011-01-15
Alpha half lives, branching ratios and hindrance factors of even-even nuclei in the range 78{<=}Z{<=}102 from ground state to ground state and ground state to excited states of daughter nuclei are computed using the Coulomb and proximity potential model for deformed nuclei (CPPMDN). The computed half life values and branching ratios are compared with experimental data and they are in good agreement. The standard deviation of half life and branching ratio are 0.79 and 0.94 respectively. It is found that the standard deviation of branching ratio for the ground state to ground state transition is only 0.25 and it increases as we move to the higher excited states which are due to the effect of nuclear structure. It is evident from the study that our ground state decay model is apt for describing not only the ground state to ground state decay but also decay to excited state.
Production of multiply charge-state ions in a multicusp ion source
Williams, M. D.; deVries, G. J.; Gough, R. A.; Leung, K. N.; Monroy, M.
1996-03-01
High charge state ion beams are commonly used in atomic and nuclear physics experiments. Multiply charged ions are normally produced in an ECR or in an EBIS. Multicusp generators can confine primary electrons very efficiently. Therefore, the electrical and gas efficiencies of these devices are high. Since the magnetic cusp fields are localized near the chamber wall, large volumes of uniform and high density plasmas can be obtained at low pressure, conditions favorable for the formation of multiply charged state ions. Attempts have been made at LBNL to generate multiply charged ion beams by employing a 25-cm diam by 25-cm long multicusp source. Experimental results demonstrated that charge states as high as 7+ can be obtained with argon or xenon plasmas. Multiply charged metallic ions such as tungsten and titanium have also been successfully formed in the multicusp source by evaporation and sputtering processes. In order to extend the charge state to higher values, a novel technique of injecting high energy electrons into the source plasma is proposed. If this is successful, the multicusp source will become very useful for radioactive beam accelerators, ion implantation, and nuclear physics applications.
Production of multiply charge-state ions in a multicusp ion source
Williams, M.D.; deVries, G.J.; Gough, R.A.; Leung, K.N.; Monroy, M. [Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)
1996-03-01
High charge state ion beams are commonly used in atomic and nuclear physics experiments. Multiply charged ions are normally produced in an ECR or in an EBIS. Multicusp generators can confine primary electrons very efficiently. Therefore, the electrical and gas efficiencies of these devices are high. Since the magnetic cusp fields are localized near the chamber wall, large volumes of uniform and high density plasmas can be obtained at low pressure, conditions favorable for the formation of multiply charged state ions. Attempts have been made at LBNL to generate multiply charged ion beams by employing a 25-cm diam by 25-cm long multicusp source. Experimental results demonstrated that charge states as high as 7+ can be obtained with argon or xenon plasmas. Multiply charged metallic ions such as tungsten and titanium have also been successfully formed in the multicusp source by evaporation and sputtering processes. In order to extend the charge state to higher values, a novel technique of injecting high energy electrons into the source plasma is proposed. If this is successful, the multicusp source will become very useful for radioactive beam accelerators, ion implantation, and nuclear physics applications. {copyright} {ital 1996 American Institute of Physics.}
A remark on ground state of boundary Izergin-Korepin model
Kojima, Takeo
2011-01-01
We study the ground state of the boundary Izergin-Korepin model. The boundary Izergin-Korepin model is defined by so-called $R$-matrix and $K$-matrix for $U_q(A_2^{(2)})$ which satisfy Yang-Baxter equation and boundary Yang-Baxter equation respectively. The ground state associated with identity $K$-matrix $K(z)=id$ was constructed in earlier study [Yang and Zhang, Nucl.Phys.B596,495-(2001)]. We construct the free field realization of the ground state associated with nontrivial diagonal $K$-matrix.
Characterization of ground state entanglement by single-qubit operations and excitation energies
Giampaolo, S M; Illuminati, F; Verrucchi, P; Giampaolo, Salvatore M.; Illuminati, Fabrizio; Siena, Silvio De; Verrucchi, Paola
2006-01-01
We consider single-qubit unitary operations and study the associated excitation energies above the ground state of interacting quantum spins. We prove that there exists a unique operation such that the vanishing of the corresponding excitation energy determines a necessary and sufficient condition for the separability of the ground state. We show that the energy difference associated to factorization exhibits a monotonic behavior with the one-tangle and the entropy of entanglement, including non analiticity at quantum critical points. The single-qubit excitation energy thus provides an independent, directly observable characterization of ground state entanglement, and a simple relation connecting two universal physical resources, energy and nonlocal quantum correlations.
Saraf, Shailendhar; Balakrishnan, Karthik; Lui, Chin Yang; Soulage, Michael; Faied, Dohy; Hanson, John; Ling, Kuok; Jaroux, Belgacem; AlRashed, Abdullah; Nassban, Badr Al; Suwaidan, Badr Al; Harbi, Mohammed Al; Salamah, Badr Bin; Othman, Mohammed Bin; Qasim, Bandar Bin; DeBra, Daniel; Byer, Robert
2016-01-01
The UV LED mission demonstrates the precise control of the potential of electrically isolated test masses that is essential for the operation of space accelerometers and drag free sensors. Accelerometers and drag free sensors were and remain at the core of geodesy, aeronomy, and precision navigation missions as well as gravitational science experiments and gravitational wave observatories. Charge management using photoelectrons generated by the 254 nm UV line of Hg was first demonstrated on Gravity Probe B and is presently part of the LISA Pathfinder technology demonstration. The UV LED mission and prior ground testing demonstrates that AlGaN UV LEDs operating at 255 nm are superior to Mercury vapor lamps because of their smaller size, lower draw, higher dynamic range, and higher control authority. We show flight data from a small satellite mission on a Saudi Satellite that demonstrates AC charge control (UV LEDs and bias are AC modulated with adjustable relative phase) between a spherical test mass and its h...
Efficient sympathetic motional ground-state cooling of a molecular ion
Wan, Yong; Wolf, Fabian; Schmidt, Piet O
2015-01-01
Cold molecular ions are promising candidates in various fields ranging from precision spectroscopy and test of fundamental physics to ultra-cold chemistry. Control of internal and external degrees of freedom is a prerequisite for many of these applications. Motional ground state cooling represents the starting point for quantum logic-assisted internal state preparation, detection, and spectroscopy protocols. Robust and fast cooling is crucial to maximize the fraction of time available for the actual experiment. We optimize the cooling rate of ground state cooling schemes for single $^{25}\\mathrm{Mg}^{+}$ ions and sympathetic ground state cooling of $^{24}\\mathrm{MgH}^{+}$. In particular, we show that robust cooling is achieved by combining pulsed Raman sideband cooling with continuous quench cooling. Furthermore, we experimentally demonstrate an efficient strategy for ground state cooling outside the Lamb-Dicke regime.
Ground-state energies of the nonlinear sigma model and the Heisenberg spin chains
Zhang, Shoucheng; Schulz, H. J.; Ziman, Timothy
1989-01-01
A theorem on the O(3) nonlinear sigma model with the topological theta term is proved, which states that the ground-state energy at theta = pi is always higher than the ground-state energy at theta = 0, for the same value of the coupling constant g. Provided that the nonlinear sigma model gives the correct description for the Heisenberg spin chains in the large-s limit, this theorem makes a definite prediction relating the ground-state energies of the half-integer and the integer spin chains. The ground-state energies obtained from the exact Bethe ansatz solution for the spin-1/2 chain and the numerical diagonalization on the spin-1, spin-3/2, and spin-2 chains support this prediction.
Processing and charge state engineering of MoOx
Aitana Tarazaga Martín-Luengo
2017-01-01
Full Text Available The effects of wet chemical processing employed in device fabrication standards are studied on molybdenum oxide (MoOx ultra-thin films. We have combined x-ray photoelectron spectroscopy (XPS, angle resolved XPS and x-ray reflectivity to gain insight into the changes in composition, structure and electronic states upon treatment of films with different initial stoichiometry prepared by reactive sputtering. Our results show significant reduction effects associated with the development of gap states in MoOx, as well as changes in the composition and structure of the films, systematically correlated with the initial oxidation state of Mo.
Processing and charge state engineering of MoOx
Martín-Luengo, Aitana Tarazaga; Köstenbauer, Harald; Winkler, Jörg; Bonanni, Alberta
2017-01-01
The effects of wet chemical processing employed in device fabrication standards are studied on molybdenum oxide (MoOx) ultra-thin films. We have combined x-ray photoelectron spectroscopy (XPS), angle resolved XPS and x-ray reflectivity to gain insight into the changes in composition, structure and electronic states upon treatment of films with different initial stoichiometry prepared by reactive sputtering. Our results show significant reduction effects associated with the development of gap states in MoOx, as well as changes in the composition and structure of the films, systematically correlated with the initial oxidation state of Mo.
Russell, C. T.; Chi, Peter; Lai, Hairong
In general, asteroids, meteoroids and dust do not interact with the plasma structures in the solar system, but after a collision between fast moving bodies the debris cloud contains nanoscale dust particles that are charged and behave like heavy ions. Dusty magnetic clouds are then accelerated to the solar wind speed. While they pose no threat to spacecraft because of the particle size, the coherency imposed by the magnetization of the cloud allows the cloud to interact with the Earth’s magnetosphere as well as the plasma in the immediate vicinity of the cloud. We call these clouds Interplanetary Field Enhancements (IFEs). These IFEs are a unique class of interplanetary field structures that feature cusp-shaped increases and decreases in the interplanetary magnetic field and a thin current sheet. The occurrence of IFEs is attributed to the interaction between the solar wind and dust particles produced in inter-bolide collisions. Previous spacecraft observations have confirmed that IFEs move with the solar wind. When IFEs strike the magnetosphere, they may distort the magnetosphere in several possible ways, such as producing a small indentation, a large scale compression, or a glancing blow. In any event if the IFE is slowed by the magnetosphere, the compression of the Earth’s field should be seen in the ground-based magnetic records that are continuously recorded. Thus it is important to understand the magnetospheric response to IFE arrival. In this study, we investigate the IFE structure observed by spacecraft upstream of the magnetosphere and the induced magnetic field perturbations observed by networks of ground magnetometers, including the THEMIS, CARISMA, McMAC arrays in North America and the IMAGE array in Europe. We find that, in a well-observed IFE event on December 24, 2006, all ground magnetometer stations observed an impulse at approximately 1217 UT when the IFE was expected to arrive at the Earth’s magnetopause. These ground stations spread across
On the Stability of Classical Orbits of the Hydrogen Ground State in Stochastic Electrodynamics
Theodorus M. Nieuwenhuizen
2016-04-01
Full Text Available De la Peña 1980 and Puthoff 1987 show that circular orbits in the hydrogen problem of Stochastic Electrodynamics connect to a stable situation, where the electron neither collapses onto the nucleus nor gets expelled from the atom. Although the Cole-Zou 2003 simulations support the stability, our recent numerics always lead to self-ionisation. Here the de la Peña-Puthoff argument is extended to elliptic orbits. For very eccentric orbits with energy close to zero and angular momentum below some not-small value, there is on the average a net gain in energy for each revolution, which explains the self-ionisation. Next, an 1 / r 2 potential is added, which could stem from a dipolar deformation of the nuclear charge by the electron at its moving position. This shape retains the analytical solvability. When it is enough repulsive, the ground state of this modified hydrogen problem is predicted to be stable. The same conclusions hold for positronium.
Different electronic charges in two-component superconductor by coherent state
Shi, Xuguang, E-mail: shixg@bjfu.edu.cn
2015-07-17
Recently, the different electronic charges, which are related to the different coupling constants with magnetic field, in the two-component superconductor have been studied in the frame of Ginzburg–Landau theory. In order to study the electronic charges in detail we suggest the wave function in the two-component superconductor to be in the coherent state. We find the different electronic charges exist not only in the coherent state but also in the incoherent state. But the ratio of the different charges in the coherent state is different from the ratio in the incoherence. The expressions of the coupling constants are given directly based on the coherence effects. We also discuss the winding number in such a system. - Highlights: • Suggest the wave function in two-component superconductor is coherent. • Interpret the existence of different electric charges by the coherent states. • Derive a new expression for the supercurrent. • Reveal the relation between different electric charges and winding number.
Yu, Z
2005-01-01
This thesis describes a Dalitz plot analysis of B0 → K+π−π 0 decays. The data sample comprises 213 million &Ugr;(4 S) → BB¯ decays collected with the BABAR detector at the PEP-II asymmetric-energy B Factory at the Stanford Linear Accelerator Center in California (SLAGC). Preliminary results are presented for measurements of the inclusive branching fraction, quasi-two-body fractions and CP-violating charge asymmetries for intermediate states including K*(892)+π − and ρ(770)−K +. Observations of B0 decays to the Kπ S-wave intermediate states, K*0 (1430)+π− and K*0 (1430)0π0, are reported. Evidence of the decay B0 → K*(892) 0π0 is seen. We set tipper limits at 90% confidence level on branching fractions of the nonresonant and other less significant intermediate states.
Pattengale, Brian; Yang, Sizhuo; Ludwig, John; Huang, Zhuangqun; Zhang, Xiaoyi; Huang, Jier
2016-07-01
Zeolitic imidazolate frameworks (ZIFs) have emerged as a novel class of porous metal-organic frameworks (MOFs) for catalysis application because of their exceptional thermal and chemical stability. Inspired by the broad absorption of ZIF-67 in UV-vis-near IR region, we explored its excited state and charge separation dynamics, properties essential for photocatalytic applications, using optical (OTA) and X-ray transient absorption (XTA) spectroscopy. OTA results show that an exceptionally long-lived excited state is formed after photoexcitation. This long-lived excited state was confirmed to be the charge-separated (CS) state with ligand-to-metal charge-transfer character using XTA. The surprisingly long-lived CS state, together with its intrinsic hybrid nature, all point to its potential application in heterogeneous photocatalysis and energy conversion.
H. Kuboki
2010-09-01
Full Text Available The charge-state distributions and equilibrium charge states of uranium (^{238}U and xenon (^{136}Xe ions at 11 MeV/nucleon were determined using a gas charge stripper. A differential pumping system facilitated the increase of the nitrogen gas thickness up to 1.3 mg/cm^{2}, which is sufficient for the most probable charge state to attain equilibrium. The charge states of ^{238}U attain equilibrium at 56.0, 56.6, and 55.7 in N_{2}, Ar, and CO_{2} media with thicknesses of 125, 79, and 126 μg/cm^{2}, respectively, while those of ^{136}Xe attain equilibrium at 40.5, 40.1, and 40.3 in N_{2}, Ar, and CO_{2} media with thicknesses of 163, 95, and 139 μg/cm^{2}, respectively. The equilibrium charge states of ^{136}Xe are acceptable for acceleration by the subsequent cyclotron. The measured data of ^{238}U were used to devise an empirical formula for the prediction of the equilibrium charge state in gaseous media over the energy region of 0.01–60 MeV/nucleon. The equilibrium charge state of ^{136}Xe as predicted by the devised formula is in good agreement with the data.
Subotnik, Joseph E.; Yeganeh, Sina; Cave, Robert J.; Ratner, Mark A.
2008-12-01
This article shows that, although Boys localization is usually applied to single-electron orbitals, the Boys method itself can be applied to many electron molecular states. For the two-state charge-transfer problem, we show analytically that Boys localization yields the same charge-localized diabatic states as those found by generalized Mulliken-Hush theory. We suggest that for future work in electron transfer, where systems have more than two charge centers, one may benefit by using a variant of Boys localization to construct diabatic potential energy surfaces and extract electronic coupling matrix elements. We discuss two chemical examples of Boys localization and propose a generalization of the Boys algorithm for creating diabatic states with localized spin density that should be useful for Dexter triplet-triplet energy transfer.
Subotnik, Joseph E; Yeganeh, Sina; Cave, Robert J; Ratner, Mark A
2008-12-28
This article shows that, although Boys localization is usually applied to single-electron orbitals, the Boys method itself can be applied to many electron molecular states. For the two-state charge-transfer problem, we show analytically that Boys localization yields the same charge-localized diabatic states as those found by generalized Mulliken-Hush theory. We suggest that for future work in electron transfer, where systems have more than two charge centers, one may benefit by using a variant of Boys localization to construct diabatic potential energy surfaces and extract electronic coupling matrix elements. We discuss two chemical examples of Boys localization and propose a generalization of the Boys algorithm for creating diabatic states with localized spin density that should be useful for Dexter triplet-triplet energy transfer.
Fan, Jianzhong; Cai, Lei; Lin, Lili; Wang, Chuan-Kui
2016-12-01
The highly efficient organic light-emitting diodes (OLEDS) based on fluorescent emitters with hybridized local and charge-transfer (HLCT) excited state have attracted great attention recently. The excited-state dynamics of the fluorescent molecule with consideration of molecular interaction are studied using the hybrid quantum mechanics/molecular mechanics method. The results show that, in solid state, the internal conversion rate (KIC) between the first singlet excited state (S1) and the ground state (S0) is smaller than the fluorescent rate (Kr), while in gas phase KIC is much larger than Kr. By analyzing the Huang-Rhys (HR) factor and reorganization energy (λ), we find that these two parameters in solid state are much smaller than those in gas phase due to the suppression of the vibration modes in low-frequency regions (solid state than that in gas phase. Moreover, combining the dynamics of the excited states and the adiabatic energy structures calculated in solid state, we illustrate the suggested "hot-exciton" mechanism of the HLCT emitters in OLEDs. Our work presents a rational explanation for the experimental results and demonstrates the importance of molecular interaction for theoretical simulation of the working principle of OLEDs.
A Rigorous Investigation on the Ground State of the Penson-Kolb Model
YANG Kai-Hua; TIAN Guang-Shan; HAN Ru-Qi
2003-01-01
By using either numerical calculations or analytical methods, such as the bosonization technique, the ground state of the Penson-Kolb model has been previously studied by several groups. Some physicists argued that, as far as the existence of superconductivity in this model is concerned, it is canonically equivalent to the negative-U Hubbard model.However, others did not agree. In the present paper, we shall investigate this model by an independent and rigorous approach. We show that the ground state of the Penson-Kolb model is nondegenerate and has a nonvanishing overlap with the ground state of the negative-U Hubbard model. Furthermore, we also show that the ground states of both the models have the same good quantum numbers and may have superconducting long-range order at the same momentum q ＝ 0. Our results support the equivalence between these models.
Bott periodicity for Z2 symmetric ground states of gapped free-fermion systems
Kennedy, Ricardo
2014-01-01
Building on the symmetry classification of disordered fermions, we give a proof of the proposal by Kitaev, and others, for a "Bott clock" topological classification of free-fermion ground states of gapped systems with symmetries. Our approach differs from previous ones in that (i) we work in the standard framework of Hermitian quantum mechanics over the complex numbers, (ii) we directly formulate a mathematical model for ground states rather than spectrally flattened Hamiltonians, and (iii) we use homotopy-theoretic tools rather than K-theory. Key to our proof is a natural transformation that squares to the standard Bott map and relates the ground state of a d-dimensional system in symmetry class s to the ground state of a (d+1)-dimensional system in symmetry class s+1. This relation gives a new vantage point on topological insulators and superconductors.
Trajectory approach to the Schrödinger–Langevin equation with linear dissipation for ground states
Chou, Chia-Chun, E-mail: ccchou@mx.nthu.edu.tw
2015-11-15
The Schrödinger–Langevin equation with linear dissipation is integrated by propagating an ensemble of Bohmian trajectories for the ground state of quantum systems. Substituting the wave function expressed in terms of the complex action into the Schrödinger–Langevin equation yields the complex quantum Hamilton–Jacobi equation with linear dissipation. We transform this equation into the arbitrary Lagrangian–Eulerian version with the grid velocity matching the flow velocity of the probability fluid. The resulting equation is simultaneously integrated with the trajectory guidance equation. Then, the computational method is applied to the harmonic oscillator, the double well potential, and the ground vibrational state of methyl iodide. The excellent agreement between the computational and the exact results for the ground state energies and wave functions shows that this study provides a synthetic trajectory approach to the ground state of quantum systems.
Exact ground-state phase diagrams for the spin-3/2 Blume Emery Griffiths model
Canko, Osman; Deviren, Bayram; Keskin, Mustafa
2008-05-01
We have calculated the exact ground-state phase diagrams of the spin-3/2 Ising model using the method that was proposed and applied to the spin-1 Ising model by Dublenych (2005 Phys. Rev. B 71 012411). The calculated, exact ground-state phase diagrams on the diatomic and triangular lattices with the nearest-neighbor (NN) interaction have been presented in this paper. We have obtained seven and 15 topologically different ground-state phase diagrams for J>0 and Jnon-uniform phases. We have also constructed the exact ground-state phase diagrams of the model on the triangular lattice and found 20 and 59 fundamental phase diagrams for J>0 and J<0, respectively, the conditions for the existence of uniform and intermediate phases have also been found.
Precision study of ground state capture in the 14N(p,gamma)15O reaction
Marta, M; Gyurky, Gy; Bemmerer, D; Broggini, C; Caciolli, A; Corvisiero, P; Costantini, H; Elekes, Z; Fülöp, Z; Gervino, G; Guglielmetti, A; Gustavino, C; Imbriani, G; Junker, M; Kunz, R; Lemut, A; Limata, B; Mazzocchi, C; Menegazzo, R; Prati, P; Roca, V; Rolfs, C; Romano, M; Alvarez, C Rossi; Somorjai, E; Straniero, O; Strieder, F; Terrasi, F; Trautvetter, H P; Vomiero, A
2008-01-01
The rate of the hydrogen-burning carbon-nitrogen-oxygen (CNO) cycle is controlled by the slowest process, 14N(p,gamma)15O, which proceeds by capture to the ground and several excited states in 15O. Previous extrapolations for the ground state contribution disagreed by a factor 2, corresponding to 15% uncertainty in the total astrophysical S-factor. At the Laboratory for Underground Nuclear Astrophysics (LUNA) 400 kV accelerator placed deep underground in the Gran Sasso facility in Italy, a new experiment on ground state capture has been carried out at 317.8, 334.4, and 353.3 keV center-of-mass energy. Systematic corrections have been reduced considerably with respect to previous studies by using a Clover detector and by adopting a relative analysis. The previous discrepancy has been resolved, and ground state capture no longer dominates the uncertainty of the total S-factor.
Correlation Effects on Charge Order and Zero-Gap State in the Organic Conductor α-(BEDT-TTF)2I3
Tanaka, Yasuhiro; Ogata, Masao
2016-10-01
The effects of electron correlation in the quasi-two-dimensional organic conductor α-(BEDT-TTF)2I3 are investigated theoretically by using an extended Hubbard model with on-site and nearest-neighbor Coulomb interactions. A variational Monte Carlo method is applied to study its ground-state properties. We show that there appears a nonmagnetic horizontal-stripe charge order in which nearest-neighbor correlation functions indicate a tendency toward a spin-singlet formation on the bonds with large transfer integrals along the charge-rich stripe. Under uniaxial pressure, a first-order transition from the nonmagnetic charge order to a zero-gap state occurs. Our results on a spin correlation length in the charge-ordered state suggest that a spin gap is almost unaffected by the uniaxial pressure in spite of the suppression of the charge disproportionation. The relevance of these contrasting behaviors in spin and charge degrees of freedom to recent experimental observations is discussed.
Charge pump DC-DC converter comprising solid state batteries
Reefman, D.; Roozeboom, F.; Notten, P.H.L.; Klootwijk, J.H.
2013-01-01
An electronic device is provided which comprises a DC-DC converter. The DC-DC converter comprises at least one solid-state rechargeable battery (B1, B2) for storing energy for the DC-DC conversion and an output capacitor (C2).
Eberly, Brandon M. [Univ. of Pittsburgh, PA (United States)
2014-01-01
Precise knowledge of neutrino-nucleus interactions is increasingly important as neutrino oscillation measurements transition into the systematics-limited era. In addition to modifying the initial interaction, the nuclear medium can scatter and absorb the interaction by-products through final state interactions, changing the types and kinematic distributions of particles seen by the detector. Recent neutrino pion production data from MiniBooNE is inconsistent with the final state interaction strength predicted by models and theoretical calculations, and some models fit best to the MiniBooNE data only after removing final state interactions entirely. This thesis presents a measurement of dσ/dT_{π} and dσ/dθ_{π} for muon-neutrino charged current charged pion production in the MINER A scintillator tracker. MINER A is a neutrino-nucleus scattering experiment installed in the few-GeV NuMI beam line at Fermilab. The analysis is limited to neutrino energies between 1.5-10 GeV. Dependence on invariant hadronic mass W is studied through two versions of the analysis that impose the limits W < 1.4 GeV and W < 1.8 GeV. The lower limit on W increases compatibility with the MiniBooNE pion data. The shapes of the differential cross sections, which depend strongly on the nature of final state interactions, are compared to Monte Carlo and theoretical predictions. It is shown that the measurements presented in this thesis favor models that contain final state interactions. Additionally, a variety of neutrino-nucleus interaction models are shown to successfully reproduce the thesis measurements, while simultaneously failing to describe the shape of the MiniBooNE data.
Ground-state entanglement in a three-spin transverse Ising model with energy current
Zhang Yong; Liu Dan; Long Gui-Lu
2007-01-01
The ground-state entanglement associated with a three-spin transverse Ising model is studied. By introducing an energy current into the system, a quantum phase transition to energy-current phase may be presented with the variation of external magnetic field; and the ground-state entanglement varies suddenly at the critical point of quantum phase transition. In our model, the introduction of energy current makes the entanglement between any two qubits become maximally robust.
Expectation values of single-particle operators in the random phase approximation ground state.
Kosov, D S
2017-02-07
We developed a method for computing matrix elements of single-particle operators in the correlated random phase approximation ground state. Working with the explicit random phase approximation ground state wavefunction, we derived a practically useful and simple expression for a molecular property in terms of random phase approximation amplitudes. The theory is illustrated by the calculation of molecular dipole moments for a set of representative molecules.
Ground-State Density Profiles of One-Dimensional Bose Gases with Anisotropic Transversal Confinement
HAO Ya-Jiang
2011-01-01
We investigate the ground-state density distributions of interacting one-dimensional Bose gases with anisotropic transversal confinement.Combining the exact ground state energy density of homogeneous bose gases with local density approximation,we determine the density distribution in each interacting regime for different anisotropic parameters.It is shown that the transversal anisotropic parameter changes the density distribution obviously,and the observed density profiles on each orientation exhibit a difference of a factor.
Hyperfine splitting in non-relativistic QED: uniqueness of the dressed hydrogen atom ground state
Amour, Laurent
2011-01-01
We consider a free hydrogen atom composed of a spin-1/2 nucleus and a spin-1/2 electron in the standard model of non-relativistic QED. We study the Pauli-Fierz Hamiltonian associated with this system at a fixed total momentum. For small enough values of the fine-structure constant, we prove that the ground state is unique. This result reflects the hyperfine structure of the hydrogen atom ground state.
Universal Wave Function Overlap and Universal Topological Data from Generic Gapped Ground States
2014-01-01
We propose a way -- universal wave function overlap -- to extract universal topological data from generic ground states of gapped systems in any dimensions. Those extracted topological data should fully characterize the topological orders with gapped or gapless boundary. For non-chiral topological orders in 2+1D, this universal topological data consist of two matrices, $S$ and $T$, which generate a projective representation of $SL(2,\\mathbb Z)$ on the degenerate ground state Hilbert space on ...
WU Feng; HE Pei; CHEN Zu-Yao; JIANG Wan-Quan
2000-01-01
The effect of the shape of suspension particle in electrorheological (ER) fluid on the ground state structure of ER solid is discussed. The results of computation show that the ground state structure will change with the shape of suspension particle. This phenomenon is a kind of phase transitions that takes the shape factors of suspension particle as tuning parameters. The variation-value of interaction energy of the lattice structure of ER solid with the shape factors of suspension particle is sometimes noticeable.
Expectation values of single-particle operators in the random phase approximation ground state
Kosov, D. S.
2017-02-01
We developed a method for computing matrix elements of single-particle operators in the correlated random phase approximation ground state. Working with the explicit random phase approximation ground state wavefunction, we derived a practically useful and simple expression for a molecular property in terms of random phase approximation amplitudes. The theory is illustrated by the calculation of molecular dipole moments for a set of representative molecules.
Patterns of the ground states in the presence of random interactions: nucleon systems
Zhao, Y M; Shimizu, N; Ogawa, K; Yoshinaga, N; Scholten, O
2004-01-01
We present our results on properties of ground states for nucleonic systems in the presence of random two-body interactions. In particular we present probability distributions for parity, seniority, spectroscopic (i.e., in the laboratory framework) quadrupole moments and $\\alpha$ clustering in the ground states. We find that the probability distribution for the parity of the ground states obtained by a two-body random ensemble simulates that of realistic nuclei: positive parity is dominant in the ground states of even-even nuclei while for odd-odd nuclei and odd-mass nuclei we obtain with almost equal probability ground states with positive and negative parity. In addition we find that for the ground states, assuming pure random interactions, low seniority is not favored, no dominance of positive values of spectroscopic quadrupole deformation, and no sign of $\\alpha$-cluster correlations, all in sharp contrast to realistic nuclei. Considering a mixture of a random and a realistic interaction, we observe a sec...
Ground-State Phases of Anisotropic Mixed Diamond Chains with Spins 1 and 1/2
Hida, Kazuo
2014-11-01
The ground-state phases of anisotropic mixed diamond chains with spins 1 and 1/2 are investigated. Both single-site and exchange anisotropies are considered. We find the phases consisting of an array of uncorrelated spin-1 clusters separated by singlet dimers. Except in the simplest case where the cluster consists of a single S = 1 spin, this type of ground state breaks the translational symmetry spontaneously. Although the mechanism leading to this type of ground state is the same as that in the isotropic case, it is nonmagnetic or paramagnetic depending on the competition between two types of anisotropy. We also find the Néel, period-doubled Néel, Haldane, and large-D phases, where the ground state is a single spin cluster of infinite size equivalent to the spin-1 Heisenberg chain with alternating anisotropies. The ground-state phase diagrams are determined for typical sets of parameters by numerical analysis. In various limiting cases, the ground-state phase diagrams are determined analytically. The low-temperature behaviors of magnetic susceptibility and entropy are investigated to distinguish each phase by observable quantities. The relationship of the present model with the anisotropic rung-alternating ladder with spin-1/2 is also discussed.
Charge-state distribution and Doppler effect in an expanding photoionized plasma.
Foord, M E; Heeter, R F; van Hoof, P A M; Thoe, R S; Bailey, J E; Cuneo, M E; Chung, H-K; Liedahl, D A; Fournier, K B; Chandler, G A; Jonauskas, V; Kisielius, R; Mix, L P; Ramsbottom, C; Springer, P T; Keenan, F P; Rose, S J; Goldstein, W H
2004-07-30
The charge state distributions of Fe, Na, and F are determined in a photoionized laboratory plasma using high resolution x-ray spectroscopy. Independent measurements of the density and radiation flux indicate unprecedented values for the ionization parameter xi=20-25 erg cm s(-1) under near steady-state conditions. Line opacities are well fitted by a curve-of-growth analysis which includes the effects of velocity gradients in a one-dimensional expanding plasma. First comparisons of the measured charge state distributions with x-ray photoionization models show reasonable agreement.
Controllable Quantum State Transfer Between a Josephson Charge Qubit and an Electronic Spin Ensemble
Yan, Run-Ying; Wang, Hong-Ling; Feng, Zhi-Bo
2016-01-01
We propose a theoretical scheme to implement controllable quantum state transfer between a superconducting charge qubit and an electronic spin ensemble of nitrogen-vacancy centers. By an electro-mechanical resonator acting as a quantum data bus, an effective interaction between the charge qubit and the spin ensemble can be achieved in the dispersive regime, by which state transfers are switchable due to the adjustable electrical coupling. With the accessible experimental parameters, we further numerically analyze the feasibility and robustness. The present scheme could provide a potential approach for transferring quantum states controllably with the hybrid system.
Continuum-state selectivity in hydrogen in Stark fields by charge-shape tuning
Ying, Y.; Nayfeh, M.H.
1987-02-15
We present numerical calculations of the photoionization of atomic hydrogen in the presence of a strong dc electric field, using three-photon excitation with two-photon resonance with intermediate Stark states. The systematics of the dependence of the cross section on the intermediate Stark states is calculated for the n = 2 to n = 9 manifolds. Our results indicate that one can use ''charge-shape tuning'' to selectively excite and enhance Stark-induced giant dipoles near E = 0 in hydrogen without the excitation of the overlapping continuum. Frequency selectivity can be used to excite from 1s (spherical charge) an intermediate whose charge is focused along the field followed by another excitation to the giant dipoles. Charge tunability can be achieved by controlling the degree of focusing by choice of the field and intermediates.
ZHU Zhiyan; ZHU Zhenghe; TANG Changhuan; TANG Yongjian; GAO Tao
2005-01-01
The present work proposes kinetics of ionization-recombination to study the charge state distribution of Au plasma. The first step is to calculate the average lifetime, energy level structure, degeneracy and partition function of Au48+―Au52+ by relativistic quantum mechanics, and next to compute the equilibrium constant and the second-order recombination rate constant by statistical thermodynamics. Based on these data, the differential equations of consecutive reversible ionization-recombination reactions are solved from which the charge state distribution and its average charge are derived. Finally, the influence of electron temperature and density on average charge is given in this paper. It is called the first-principle theory, for no experimental data are needed.
Penning De Vries, René G.M.; Wallinga, Hans
1984-01-01
The small-signal charge transfer inefficiency (SCTI) of a surface-channel CCD has been studied. The experimentally observed behavior of the SCTI could not be explained by the conventional interface state model. Using the McWhorter model for the interface states, which assumes a distribution of the s
Karki, Santosh; Sistani, Habiballah; Archer, Jieutonne J.; Shi, Fengjian; Levis, Robert J.
2017-01-01
Charge state distributions are measured using mass spectrometry for both native and denatured cytochrome c and myoglobin after laser vaporization from the solution state into an electrospray (ES) plume consisting of a series of solution additives differing in gas-phase basicity. The charge distribution depends on both the pH of the protein solution prior to laser vaporization and the gas-phase basicity of the solution additive employed in the ES solvent. Cytochrome c (myoglobin) prepared in solutions with pH of 7.0, 2.6, and 2.3 resulted in the average charge state distribution (Zavg) of 7.0 ± 0.1 (8.2 ± 0.1), 9.7 ± 0.2 (14.5 ± 0.3), and 11.6 ± 0.3 (16.4 ± 0.1), respectively, in ammonium formate ES solvent. The charge distribution shifted from higher charge states to lower charge states when the ES solvent contained amines additives with higher gas-phase basicity. In the case of triethyl ammonium formate, Zavg of cytochrome c (myoglobin) prepared in solutions with pH of 7.0, 2.6, and 2.3 decreased to 4.9 (5.7), 7.4 ± 0.2 (9.6 ± 0.3), and 7.9 ± 0.3 (9.8 ± 0.2), respectively. The detection of a charge state distribution corresponding to folded protein after laser vaporized, acid-denatured protein interacts with the ES solvent containing ammonium formate, ammonium acetate, triethyl ammonium formate, and triethyl ammonium acetate suggests that at least a part of protein population folds within the electrospray droplet on a millisecond timescale.
Karki, Santosh; Sistani, Habiballah; Archer, Jieutonne J.; Shi, Fengjian; Levis, Robert J.
2017-03-01
Charge state distributions are measured using mass spectrometry for both native and denatured cytochrome c and myoglobin after laser vaporization from the solution state into an electrospray (ES) plume consisting of a series of solution additives differing in gas-phase basicity. The charge distribution depends on both the pH of the protein solution prior to laser vaporization and the gas-phase basicity of the solution additive employed in the ES solvent. Cytochrome c (myoglobin) prepared in solutions with pH of 7.0, 2.6, and 2.3 resulted in the average charge state distribution (Zavg) of 7.0 ± 0.1 (8.2 ± 0.1), 9.7 ± 0.2 (14.5 ± 0.3), and 11.6 ± 0.3 (16.4 ± 0.1), respectively, in ammonium formate ES solvent. The charge distribution shifted from higher charge states to lower charge states when the ES solvent contained amines additives with higher gas-phase basicity. In the case of triethyl ammonium formate, Zavg of cytochrome c (myoglobin) prepared in solutions with pH of 7.0, 2.6, and 2.3 decreased to 4.9 (5.7), 7.4 ± 0.2 (9.6 ± 0.3), and 7.9 ± 0.3 (9.8 ± 0.2), respectively. The detection of a charge state distribution corresponding to folded protein after laser vaporized, acid-denatured protein interacts with the ES solvent containing ammonium formate, ammonium acetate, triethyl ammonium formate, and triethyl ammonium acetate suggests that at least a part of protein population folds within the electrospray droplet on a millisecond timescale.
Detection and control of charge states in a quintuple quantum dot
Ito, Takumi; Otsuka, Tomohiro; Amaha, Shinichi; Delbecq, Matthieu R.; Nakajima, Takashi; Yoneda, Jun; Takeda, Kenta; Allison, Giles; Noiri, Akito; Kawasaki, Kento; Tarucha, Seigo
2016-12-01
A semiconductor quintuple quantum dot with two charge sensors and an additional contact to the center dot from an electron reservoir is fabricated to demonstrate the concept of scalable architecture. This design enables formation of the five dots as confirmed by measurements of the charge states of the three nearest dots to the respective charge sensor. The gate performance of the measured stability diagram is well reproduced by a capacitance model. These results provide an important step towards realizing controllable large scale multiple quantum dot systems.
Topological charges in 2d N=(2,2) theories and massive BPS states
Park, Daniel S
2015-01-01
We study how charges of global symmetries that are manifest in the ultra-violet definition of a theory are realized as topological charges in its infra-red effective theory for two-dimensional theories with $\\mathcal{N}=(2,2)$ supersymmetry. We focus on the charges that the states living on $S^1$ carry. The central charge---or BPS masses---of the supersymmetry algebra play a crucial role in making this correspondence precise. We study two examples: $U(1)$ gauge theories with chiral matter, and world-volume theories of "dynamical surface operators" of 4d $\\mathcal{N}=2$ gauge theories. In the former example, we show that the flavor charges of the theory are realized as topological winding numbers in the effective theory on the Coulomb branch. In the latter, we show that there is a one-to-one correspondence between topological charges of the effective theory of the dynamical surface operator and the electric, magnetic, and flavor charges of the 4d gauge theory. We also examine the topologically charged massive ...
Mendoza-Hernandez, Omar Samuel; Ishikawa, Hiroaki; Nishikawa, Yuuki; Maruyama, Yuki; Umeda, Minoru
2015-04-01
The analysis of Li-ion secondary cells under outstanding conditions, as overcharge and high temperatures, is important to determine thermal abuse characteristics of electroactive materials and precise risk assessments on Li-ion cells. In this work, the thermal runaway behavior of LiCoO2 and LiMn2O4 cathode materials were compared at different state of charges (SOCs), including overcharge, by carrying out accelerating rate calorimetry (ARC) measurements using 18650 Li-ion cells. Onset temperatures of self-heating reactions and thermal runaway behavior were identified, and by using these onset points thermal mapping plots were made. We were able to identify non-self-heating, self-heating and thermal runaway regions as a function of state of charge and temperature. The cell using LiMn2O4 cathode material was found to be more thermally stable than the cell using LiCoO2. In parallel with the ARC measurements, the electrochemical behavior of the cells was monitored by measuring the OCV and internal resistance of the cells. The electrochemical behavior of the cells showed a slightly dependency on SOC.
Performance characteristics of a battery charger and state-of-charge indicator
Edwards, D.; Klein, J.
1984-01-01
A battery charge/state of charge indicator (BC/SCI) system for electric vehicle use was developed. The original and subsequent objectives for the BC/SCI and the rationale for those objectives are described. The requirements generated from the objectives are listed and a description of the BC/SCI is provided. The power section problem, the tests, and the test results are discussed.
Defect charge states in Si doped hexagonal boron-nitride monolayer.
Mapasha, R E; Molepo, M P; Andrew, R C; Chetty, N
2016-02-10
We perform ab initio density functional theory calculations to investigate the energetics, electronic and magnetic properties of isolated stoichiometric and non-stoichiometric substitutional Si complexes in a hexagonal boron-nitride monolayer. The Si impurity atoms substituting the boron atom sites SiB giving non-stoichiometric complexes are found to be the most energetically favourable, and are half-metallic and order ferromagnetically in the neutral charge state. We find that the magnetic moments and magnetization energies increase monotonically when Si defects form a cluster. Partial density of states and standard Mulliken population analysis indicate that the half-metallic character and magnetic moments mainly arise from the Si 3p impurity states. The stoichiometric Si complexes are energetically unfavorable and non-magnetic. When charging the energetically favourable non-stoichiometric Si complexes, we find that the formation energies strongly depend on the impurity charge states and Fermi level position. We also find that the magnetic moments and orderings are tunable by charge state modulation q = -2, -1, 0, +1, +2. The induced half-metallic character is lost (retained) when charging isolated (clustered) Si defect(s). This underlines the potential of a Si doped hexagonal boron-nitride monolayer for novel spin-based applications.
Karaveli, Sinan; Gaathon, Ophir; Wolcott, Abraham; Sakakibara, Reyu; Shemesh, Or A.; Peterka, Darcy S.; Boyden, Edward S.; Owen, Jonathan S.; Yuste, Rafael; Englund, Dirk
2016-04-01
The negatively charged nitrogen vacancy (NV-) center in diamond has attracted strong interest for a wide range of sensing and quantum information processing applications. To this end, recent work has focused on controlling the NV charge state, whose stability strongly depends on its electrostatic environment. Here, we demonstrate that the charge state and fluorescence dynamics of single NV centers in nanodiamonds with different surface terminations can be controlled by an externally applied potential difference in an electrochemical cell. The voltage dependence of the NV charge state can be used to stabilize the NV- state for spin-based sensing protocols and provides a method of charge state-dependent fluorescence sensing of electrochemical potentials. We detect clear NV fluorescence modulation for voltage changes down to 100 mV, with a single NV and down to 20 mV with multiple NV centers in a wide-field imaging mode. These results suggest that NV centers in nanodiamonds could enable parallel optical detection of biologically relevant electrochemical potentials.
Karaveli, Sinan; Gaathon, Ophir; Wolcott, Abraham; Sakakibara, Reyu; Shemesh, Or A; Peterka, Darcy S; Boyden, Edward S; Owen, Jonathan S; Yuste, Rafael; Englund, Dirk
2016-04-12
The negatively charged nitrogen vacancy (NV(-)) center in diamond has attracted strong interest for a wide range of sensing and quantum information processing applications. To this end, recent work has focused on controlling the NV charge state, whose stability strongly depends on its electrostatic environment. Here, we demonstrate that the charge state and fluorescence dynamics of single NV centers in nanodiamonds with different surface terminations can be controlled by an externally applied potential difference in an electrochemical cell. The voltage dependence of the NV charge state can be used to stabilize the NV(-) state for spin-based sensing protocols and provides a method of charge state-dependent fluorescence sensing of electrochemical potentials. We detect clear NV fluorescence modulation for voltage changes down to 100 mV, with a single NV and down to 20 mV with multiple NV centers in a wide-field imaging mode. These results suggest that NV centers in nanodiamonds could enable parallel optical detection of biologically relevant electrochemical potentials.
A vacuum spark ion source: High charge state metal ion beams
Yushkov, G. Yu., E-mail: gyushkov@mail.ru; Nikolaev, A. G.; Frolova, V. P. [High Current Electronics Institute, Siberian Branch of the Russian Academy of Science, Tomsk 634055 (Russian Federation); Oks, E. M. [High Current Electronics Institute, Siberian Branch of the Russian Academy of Science, Tomsk 634055 (Russian Federation); Tomsk State University of Control System and Radioelectronics, Tomsk 634050 (Russian Federation)
2016-02-15
High ion charge state is often important in ion beam physics, among other reasons for the very practical purpose that it leads to proportionately higher ion beam energy for fixed accelerating voltage. The ion charge state of metal ion beams can be increased by replacing a vacuum arc ion source by a vacuum spark ion source. Since the voltage between anode and cathode remains high in a spark discharge compared to the vacuum arc, higher metal ion charge states are generated which can then be extracted as an ion beam. The use of a spark of pulse duration less than 10 μs and with current up to 10 kA allows the production of ion beams with current of several amperes at a pulse repetition rate of up to 5 pps. We have demonstrated the formation of high charge state heavy ions (bismuth) of up to 15 + and a mean ion charge state of more than 10 +. The physics and techniques of our vacuum spark ion source are described.
Charge state evolution in the solar wind. III. Model comparison with observations
Landi, E.; Oran, R.; Lepri, S. T.; Zurbuchen, T. H.; Fisk, L. A.; Van der Holst, B. [Department of Atmospheric, Oceanic and Space Sciences, University of Michigan, Ann Arbor, MI 48109 (United States)
2014-08-01
We test three theoretical models of the fast solar wind with a set of remote sensing observations and in-situ measurements taken during the minimum of solar cycle 23. First, the model electron density and temperature are compared to SOHO/SUMER spectroscopic measurements. Second, the model electron density, temperature, and wind speed are used to predict the charge state evolution of the wind plasma from the source regions to the freeze-in point. Frozen-in charge states are compared with Ulysses/SWICS measurements at 1 AU, while charge states close to the Sun are combined with the CHIANTI spectral code to calculate the intensities of selected spectral lines, to be compared with SOHO/SUMER observations in the north polar coronal hole. We find that none of the theoretical models are able to completely reproduce all observations; namely, all of them underestimate the charge state distribution of the solar wind everywhere, although the levels of disagreement vary from model to model. We discuss possible causes of the disagreement, namely, uncertainties in the calculation of the charge state evolution and of line intensities, in the atomic data, and in the assumptions on the wind plasma conditions. Last, we discuss the scenario where the wind is accelerated from a region located in the solar corona rather than in the chromosphere as assumed in the three theoretical models, and find that a wind originating from the corona is in much closer agreement with observations.
A vacuum spark ion source: High charge state metal ion beams
Yushkov, G. Yu.; Nikolaev, A. G.; Oks, E. M.; Frolova, V. P.
2016-02-01
High ion charge state is often important in ion beam physics, among other reasons for the very practical purpose that it leads to proportionately higher ion beam energy for fixed accelerating voltage. The ion charge state of metal ion beams can be increased by replacing a vacuum arc ion source by a vacuum spark ion source. Since the voltage between anode and cathode remains high in a spark discharge compared to the vacuum arc, higher metal ion charge states are generated which can then be extracted as an ion beam. The use of a spark of pulse duration less than 10 μs and with current up to 10 kA allows the production of ion beams with current of several amperes at a pulse repetition rate of up to 5 pps. We have demonstrated the formation of high charge state heavy ions (bismuth) of up to 15 + and a mean ion charge state of more than 10 +. The physics and techniques of our vacuum spark ion source are described.
Alpha decay of {sup 184-224}Bi isotopes from the ground state and isomeric state
Santhosh, K.P.; Priyanka, B. [Kannur University, School of Pure and Applied Physics, Kerala (India)
2013-12-15
The {alpha} -decay half-lives for the favored and unfavored transitions of the isotopes of Bi (Z = 83) nuclei in the region 184 {<=}A {<=} 224, from both the ground state (g.s.) and the isomeric state (i.s.) have been studied systematically within the Coulomb and proximity potential model (CPPM). The half-lives have been evaluated using the experimental Q-values. The computed half-lives are compared with the experimental data and they are in good agreement. We have modified the assault frequency and redetermined the half-lives and they show a better agreement with the experimental value. The standard deviation of the logarithm of the half-life with the former assault frequency is found to be 1.234 and with the modified assault frequency, it is found to be 0.935. This reveals that the CPPM, with the modified deformation-dependent assault frequency is more apt for the alpha-decay studies. Using our model we could also demonstrate the influence of the N = 126, neutron shell closure in both parent and daughter nuclei on the alpha-decay half-lives. (orig.)
Suo, Bingbing; Han, Huixian
2014-01-01
We present the fully relativistic multi-reference configuration interaction calculations of the ground and low-lying excited electronic states of IrO for individual spin-orbit component. The lowest states for four spin-orbit components 1/2, 3/2, 5/2, and 7/2 are calculated intensively to clarify the ground state of IrO. Our calculation suggests that the ground state is of 1/2 spin-orbit component, which is highly mixed with $^4\\Sigma^-$ and $^2\\Pi$ states in $\\Lambda-S$ notation. The two low-lying states of the 5/2 and 7/2 spin-orbit components are nearly degenerate with the ground state and locate only 234 and 260 cm$^{-1}$ above, respectively. The equilibrium bond length 1.712 \\AA \\ and harmonic vibrational frequency 903 cm$^{-1}$ of the 5/2 spin-orbit component are close to the experimental measurement of 1.724 \\AA \\ and 909 cm$^{-1}$, which suggests the 5/2 state should be the low-lying state contributed to spectra in experimental study. Moreover, the electronic states that give rise to the observed trans...
Ordered ground states of metallic hydrogen and deuterium
Ashcroft, N. W.
1981-01-01
The physical attributes of some of the more physically distinct ordered states of metallic hydrogen and metallic deuterium at T = 0 and nearby are discussed. The likelihood of superconductivity in both is considered with respect to the usual coupling via the density fluctuations of the ions.
Delin, Geoffrey N.; Risser, Dennis W.
2007-01-01
Increased demands on water resources by a growing population and recent droughts have raised awareness about the adequacy of ground-water resources in humid areas of the United States. The spatial and temporal variability of ground-water recharge are key factors that need to be quantified to determine the sustainability of ground-water resources. Ground-water recharge is defined herein as the entry into the saturated zone of water made available at the water-table surface, together with the associated flow away from the water table within the saturated zone (Freeze and Cherry, 1979). In response to the need for better estimates of ground-water recharge, the Ground-Water Resources Program (GWRP) of the U.S. Geological Survey (USGS) began an initiative in 2003 to estimate ground-water recharge rates in the relatively humid areas of the United States.
Bandyopadhyay, Subhajit; Roy, Saswata
2014-01-01
This paper describes an inexpensive experiment to determine the carbonyl stretching frequency of an organic keto compound in its ground state and first electronic excited state. The experiment is simple to execute, clarifies some of the fundamental concepts of spectroscopy, and is appropriate for a basic spectroscopy laboratory course. The…
Bandyopadhyay, Subhajit; Roy, Saswata
2014-01-01
This paper describes an inexpensive experiment to determine the carbonyl stretching frequency of an organic keto compound in its ground state and first electronic excited state. The experiment is simple to execute, clarifies some of the fundamental concepts of spectroscopy, and is appropriate for a basic spectroscopy laboratory course. The…
Degenerate ground states and multiple bifurcations in a two-dimensional q-state quantum Potts model.
Dai, Yan-Wei; Cho, Sam Young; Batchelor, Murray T; Zhou, Huan-Qiang
2014-06-01
We numerically investigate the two-dimensional q-state quantum Potts model on the infinite square lattice by using the infinite projected entangled-pair state (iPEPS) algorithm. We show that the quantum fidelity, defined as an overlap measurement between an arbitrary reference state and the iPEPS ground state of the system, can detect q-fold degenerate ground states for the Z_{q} broken-symmetry phase. Accordingly, a multiple bifurcation of the quantum ground-state fidelity is shown to occur as the transverse magnetic field varies from the symmetry phase to the broken-symmetry phase, which means that a multiple-bifurcation point corresponds to a critical point. A (dis)continuous behavior of quantum fidelity at phase transition points characterizes a (dis)continuous phase transition. Similar to the characteristic behavior of the quantum fidelity, the magnetizations, as order parameters, obtained from the degenerate ground states exhibit multiple bifurcation at critical points. Each order parameter is also explicitly demonstrated to transform under the Z_{q} subgroup of the symmetry group of the Hamiltonian. We find that the q-state quantum Potts model on the square lattice undergoes a discontinuous (first-order) phase transition for q=3 and q=4 and a continuous phase transition for q=2 (the two-dimensional quantum transverse Ising model).
Charge Transfer and Triplet States in High Efficiency OPV Materials and Devices
Dyakonov, Vladimir
2013-03-01
The advantage of using polymers and molecules in electronic devices, such as light-emitting diodes (LED), field-effect transistors (FET) and, more recently, solar cells (SC) is justified by the unique combination of high device performance and processing of the semiconductors used. Power conversion efficiency of nanostructured polymer SC is in the range of 10% on lab scale, making them ready for up-scaling. Efficient charge carrier generation and recombination in SC are strongly related to dissociation of the primary singlet excitons. The dissociation (or charge transfer) process should be very efficient in photovoltaics. The mechanisms governing charge carrier generation, recombination and transport in SC based on the so-called bulk-heterojunctions, i.e. blends of two or more semiconductors with different electron affinities, appear to be very complex, as they imply the presence of the intermediate excited states, neutral and charged ones. Charge transfer states, or polaron pairs, are the intermediate states between free electrons/holes and strongly bound excitons. Interestingly, the mostly efficient OLEDs to date are based on the so-called triplet emitters, which utilize the triplet-triplet annihilation process. In SC, recent investigations indicated that on illumination of the device active layer, not only mobile charges but also triplet states were formed. With respect to triplets, it is unclear how these excited states are generated, via inter-system crossing or via back transfer of the electron from acceptor to donor. Triplet formation may be considered as charge carrier loss channel; however, the fusion of two triplets may lead to a formation of singlet excitons instead. In such case, a generation of charges by utilizing of the so far unused photons will be possible. The fundamental understanding of the processes involving the charge transfer and triplet states and their relation to nanoscale morphology and/or energetics of blends is essential for the
Charge state distribution analysis of Al and Pb ions from the laser ion source at IMP
Shan, Sha; Zhang-Min, Li; Xiao-Hong, Guo; Lun-Cai, Zhou; Guo-Zhu, Cai; Liang-ting, Sun; Xue-Zhen, Zhang; Huan-Yu, Zhao; Xi-Meng, Chen; Hong-Wei, Zhao
2013-01-01
A prototype laser ion source that could demonstrate the possibility of producing intense pulsed high charge state ion beams has been established with a commercial Nd:YAG laser (E max = 3 J, 1064 nm, 8-10 ns) to produce laser plasma for the research of Laser Ion Source (LIS). At the laser ion source test bench, high purity (99.998 %) aluminum and lead targets have been tested for laser plasma experiment. An Electrostatic Ion Analyzer (EIA) and Electron Multiply Tube (EMT) detector were used to analyze the charge state and energy distribution of the ions produced by the laser ion source. The maximum charge states of Al12+ and Pb7+ were achieved. The results will be presented and discussed in this paper.
Kakehashi, Yoshiro; Chandra, Sumal
2016-08-01
The ground-state properties of iron-group transition metals from Sc to Cu have been investigated on the basis of the first-principles momentum dependent local ansatz (MLA) theory. Correlation energy gain is found to show large values for Mn and Fe: 0.090 Ry (Mn) and 0.094 Ry (Fe). The Hund-rule coupling energies are found to be 3000 K (Fe), 1400 K (Co), and 300 K (Ni). It is suggested that these values can resolve the inconsistency in magnetic energy between the density functional theory and the first-principles dynamical coherent potential approximation theory at finite temperatures. Charge fluctuations are shown to be suppressed by the intra-orbital correlations and inter-orbital charge-charge correlations, so that they show nearly constant values from V to Fe: 1.57 (V and Cr), 1.52 (Mn), and 1.44 (Fe), which are roughly twice as large as those obtained by the d band model. The amplitudes of local moments are enhanced by the intra-orbital and inter-orbital spin-spin correlations and show large values for Mn and Fe: 2.87 (Mn) and 2.58 (Fe). These values are in good agreement with the experimental values estimated from the effective Bohr magneton number and the inner core photoemission data.
Tillman, Fred D; Leake, Stanley A.; Flynn, Marilyn E.; Cordova, Jeffrey T.; Schonauer, Kurt T.; Dickinson, Jesse E.
2008-01-01
Monitoring the status and trends in the availability of the Nation's ground-water supplies is important to scientists, planners, water managers, and the general public. This is especially true in the semiarid to arid southwestern United States where rapid population growth and limited surface-water resources have led to increased use of ground-water supplies and water-level declines of several hundred feet in many aquifers. Individual well observations may only represent aquifer conditions in a limited area, and wells may be screened over single or multiple aquifers, further complicating single-well interpretations. Additionally, changes in ground-water conditions may involve time scales ranging from days to many decades, depending on the timing of recharge, soil and aquifer properties, and depth to the water table. The lack of an easily identifiable ground-water property indicative of current conditions, combined with differing time scales of water-level changes, makes the presentation of ground-water conditions a difficult task, particularly on a regional basis. One approach is to spatially present several indicators of ground-water conditions that address different time scales and attributes of the aquifer systems. This report describes several methods and indicators for presenting differing aspects of ground-water conditions using water-level observations in existing data-sets. The indicators of ground-water conditions developed in this study include areas experiencing water-level decline and water-level rise, recent trends in ground-water levels, and current depth to ground water. The computer programs written to create these indicators of ground-water conditions and display them in an interactive geographic information systems (GIS) format are explained and results illustrated through analyses of ground-water conditions for selected alluvial basins in the Lower Colorado River Basin in Arizona.
The ground electronic state of KCs studied by Fourier transform spectroscopy
Ferber, R.; Klincare, I.; Nikolayeva, O.; Tamanis, M.; Knöckel, H.; Tiemann, E.; Pashov, A.
2008-06-01
We present here the first analysis of laser induced fluorescence (LIF) of the KCs molecule obtaining highly accurate data and perform a direct potential construction for the X 1Σ+ ground state in a wide range of internuclear distances. KCs molecules were produced by heating a mixture of K and Cs metals in a heat pipe at a temperature of about 270 °C. KCs fluorescence was induced by different laser sources: the 454.5, 457.9, 465.8, and 472.7 nm lines of an Ar+ laser, a dye laser with Rhodamine 6G dye (excitation at around 16 870 cm-1), and 850 and 980 nm diode lasers (11 500-11 900 and 10 200-10 450 cm-1 tuning ranges, respectively). The LIF to the ground state was recorded by a Bruker IFS-125HR Fourier transform spectrometer with a spectral resolution of 0.03 cm-1. Particularly, by applying the 850 nm laser diode we were able to observe LIF progressions to very high vibrational levels of the ground state close to the dissociation limit. The present data field contains 7226 term values for the ground state X 1Σ+ and covers a range from v''=0 to 97 with J'' varying from 12 to 209. More than 10 000 fluorescence lines were used to fit the ground state potential energy curve via the inverted perturbation approach procedure. The present empirical potential extends up to approximately 12.6 A˚ and covers more than 99% of the potential well depth, it describes most of the spectral lines with an accuracy of about 0.003 cm-1 and yields a dissociation energy of 4069.3+/-1.5 cm-1 for the ground state X 1Σ+. First observations of the triplet ground state a 3Σ+ of KCs are presented, and preliminary values of few main molecular constants could be derived.
Chen, Xiang-Dong; Shen, Ao; Dong, Yang; Dong, Chun-Hua; Guo, Guang-Can; Sun, Fang-Wen
2016-01-01
The near-infrared (NIR) optical pumped photophysics of nitrogen vacancy (NV) center in diamond was experimentally studied by considering both the charge state conversion and stimulated emission. We found that the NIR laser can help to highly enhance the charge state conversion rate, which can be applied to improve the performance of charge state depletion nanoscopy. Using a doughnut-shaped visible laser beam and a Gaussian-shaped NIR laser beam for charge state manipulation, we developed a low power charge state depletion nanoscopy for NV center. A spatial resolution of 14 nm was achieved with the depletion laser intensity approximately three orders lower than that used for the stimulated emission depletion nanoscopy with NV center. With high spatial resolution and low laser power, the nanoscopy can be used for nanoscale quantum sensing with NV center. And our study on the charge state conversion can help to further optimize the NV center spin state initialization and detection.
Mandrà, Salvatore; Zhu, Zheng; Katzgraber, Helmut G.
2017-02-01
We study the performance of the D-Wave 2X quantum annealing machine on systems with well-controlled ground-state degeneracy. While obtaining the ground state of a spin-glass benchmark instance represents a difficult task, the gold standard for any optimization algorithm or machine is to sample all solutions that minimize the Hamiltonian with more or less equal probability. Our results show that while naive transverse-field quantum annealing on the D-Wave 2X device can find the ground-state energy of the problems, it is not well suited in identifying all degenerate ground-state configurations associated with a particular instance. Even worse, some states are exponentially suppressed, in agreement with previous studies on toy model problems [New J. Phys. 11, 073021 (2009), 10.1088/1367-2630/11/7/073021]. These results suggest that more complex driving Hamiltonians are needed in future quantum annealing machines to ensure a fair sampling of the ground-state manifold.
Conformal anisotropic relativistic charged fluid spheres with a linear equation of state
Esculpi, M.; Alomá, E.
2010-06-01
We obtain two new families of compact solutions for a spherically symmetric distribution of matter consisting of an electrically charged anisotropic fluid sphere joined to the Reissner-Nordstrom static solution through a zero pressure surface. The static inner region also admits a one parameter group of conformal motions. First, to study the effect of the anisotropy in the sense of the pressures of the charged fluid, besides assuming a linear equation of state to hold for the fluid, we consider the tangential pressure p ⊥ to be proportional to the radial pressure p r , the proportionality factor C measuring the grade of anisotropy. We analyze the resulting charge distribution and the features of the obtained family of solutions. These families of solutions reproduce for the value C=1, the conformal isotropic solution for quark stars, previously obtained by Mak and Harko. The second family of solutions is obtained assuming the electrical charge inside the sphere to be a known function of the radial coordinate. The allowed values of the parameters pertained to these solutions are constrained by the physical conditions imposed. We study the effect of anisotropy in the allowed compactness ratios and in the values of the charge. The Glazer’s pulsation equation for isotropic charged spheres is extended to the case of anisotropic and charged fluid spheres in order to study the behavior of the solutions under linear adiabatic radial oscillations. These solutions could model some stage of the evolution of strange quark matter fluid stars.
Jarowski, Peter D; Mo, Yirong
2014-12-15
The structural weights of the canonical resonance contributors used in the Two-state valence-bond charge-transfer model, neutral (N, R1) and ionic (VB-CT, R2), to the ground states and excited states of a series of linear dipolar intramolecular charge-transfer chromophores containing a buta-1,3-dien-1,4-diyl bridge have been computed by using the block-localized wavefunction (BLW) method at the B3LYP/6-311+G(d) level to provide the first quantitative assessment of this simple model. Ground- and excited-state analysis reveals surprisingly low ground-state structural weights for the VB-CT resonance form using either this Two-state model or an expanded Ten-state model. The VB-CT state is found to be more prominent in the excited state. Individual resonance forms were structurally optimized to understand the origins of the bond length alternation (BLA) of the bridging unit. Using a Wheland energy-based weighting scheme, the weighted average of the optimized bond lengths with the Two-state model was unable to reproduce the BLA features with values 0.04 to 0.02 Å too large compared to the fully delocalized (FD) structure (BLW: ca. -0.13 to -0.07 Å, FD: ca. -0.09 to -0.05 Å). Instead, an expanded Ten-state model fit the BLA values of the FD structure to within only 0.001 Å of FD. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Li, Pengfei; Jackson, Glen P.
2017-01-01
1+, 2+, and 3+ precursors of substance P and bradykinin were subjected to helium cation irradiation in a 3D ion trap mass spectrometer. Charge exchange with the helium cations produces a variety of fragment ions, the number and type of which are dependent on the charge state of the precursor ions. For 1+ peptide precursors, fragmentation is generally restricted to C-CO backbone bonds (a and x ions), whereas for 2+ and 3+ peptide precursors, all three backbone bonds (C-CO, C-N, and N-Cα) are cleaved. The type of backbone bond cleavage is indicative of possible dissociation channels involved in CTD process, including high-energy, kinetic-based, and ETD-like pathways. In addition to backbone cleavages, amino acid side-chain cleavages are observed in CTD, which are consistent with other high-energy and radical-mediated techniques. The unique dissociation pattern and supplementary information available from side-chain cleavages make CTD a potentially useful activation method for the structural study of gas-phase biomolecules.
Ground State Transitions in Vertically Coupled Four-Layer Single Electron Quantum Dots
WANGAn-Mei; XIEWen-Fang
2005-01-01
We study a four-electron system in a vertically coupled four-layer quantum dot under a magnetic field by the exact diagonalization of the Hamiltonian matr/x. We find that discontinuous ground-state energy transitions are induced by an external magnetic field. We find that dot-dot distance and electron-electron interaction strongly affect the low-lying states of the coupled quantum dots. The inter-dot correlation leads to some sequences of possible disappearances of ground state transitions, which are present for uncoupled dots.
Ground State Transitions in Vertically Coupled Four-Layer Single Electron Quantum Dots
WANG An-Mei; XIE Wen-Fang
2005-01-01
We study a four-electron system in a vertically coupled four-layer quantum dot under a magnetic field by the exact diagonalization of the Hamiltonian matrix. We find that discontinuous ground-state energy transitions are induced by an external magnetic field. We find that dot-dot distance and electron-electron interaction strongly affect the low-lying states of the coupled quantum dots. The inter-dot correlation leads to some sequences of possible disappearances of ground state transitions, which are present for uncoupled dots.
Vacuum polarization in the ground states of bi-muonic helium atoms
Frolov, Alexei M.
2004-11-01
The energies and bound-state properties of the bi-muonic helium-3 and helium-4 atoms in their ground 11(S = 0)-states are determined to very high accuracy. It is shown that the lowest order QED (and relativistic) effects play a significantly larger role in the case of bi-muonic 3Heμ2 and 4Heμ2 atoms than in the two-electron He-atoms. In particular, the effect of vacuum polarization and corresponding energy shifts for the ground 11(S = 0)-states in the bi-muonic helium-3 and helium-4 atoms have been evaluated.
Spin-Orbit Coupling Controlled J =3 /2 Electronic Ground State in 5 d3 Oxides
Taylor, A. E.; Calder, S.; Morrow, R.; Feng, H. L.; Upton, M. H.; Lumsden, M. D.; Yamaura, K.; Woodward, P. M.; Christianson, A. D.
2017-05-01
Entanglement of spin and orbital degrees of freedom drives the formation of novel quantum and topological physical states. Here we report resonant inelastic x-ray scattering measurements of the transition metal oxides Ca3 LiOsO6 and Ba2 YOsO6 , which reveals a dramatic spitting of the t2 g manifold. We invoke an intermediate coupling approach that incorporates both spin-orbit coupling and electron-electron interactions on an even footing and reveal that the ground state of 5 d3-based compounds, which has remained elusive in previously applied models, is a novel spin-orbit entangled J =3 /2 electronic ground state. This work reveals the hidden diversity of spin-orbit controlled ground states in 5 d systems and introduces a new arena in the search for spin-orbit controlled phases of matter.
Exact many-electron ground states on the diamond Hubbard chain
Gulacsi, Zsolt; Kampf, Arno; Vollhardt, Dieter
2008-03-01
Exact ground states of interacting electrons on the diamond Hubbard chain in a magnetic field are constructed which exhibit a wide range of properties such as flat-band ferromagnetism, correlation induced metallic, half-metallic, or insulating behavior [1]. The properties of these ground states can be tuned by changing the magnetic flux, local potentials, or electron density.The results show that the studied simple one-dimensional structure displays remarkably complex physical properties. The virtue of tuning different ground states through external parameters points to new possibilities for the design of electronic devices which can switch between insulating or conducting and nonmagnetic or (fully or partially spin polarized) ferromagnetic states, open new routes for the design of spin-valve devices and gate induced ferromagnetism. [1] Z. Gulacsi, A. Kampf, D. Vollhardt, Phys. Rev. Lett. 99, 026404(2007).
A novel approach to kinetic energy release distribution and charge state distribution measurements
Lee, Kaidee [National Synchrotron Radiation Research Center, Hsinchu 30077, Taiwan (China)]. E-mail: lee@nsrrc.org.tw
2005-06-15
When a swarm of ions are accelerated by a pulsed electric field for a common duration before entering an electrostatically dispersive energy analyzer, they will be sorted according to their charge-to-mass ratio q/m. In other words, the apparent kinetic energy upon which an ion will be registered in an apparent 'energy' spectrum thus obtained is proportional to its q/m ratio. For ions of a fixed mass m, the apparent energy spectrum becomes a charge state distribution spectrum. For ions of a fixed charge q, the apparent energy spectrum becomes a mass spectrum. In essence, an energy analyzer becomes both a charge sorter and a mass spectrometer when operated in this mode. In addition, when applied to the detection of photofragment ions, this technique will be able to yield information on the kinetic energy release distribution of the underlying dissociation events.
Ground-state energy of the q-state Potts model: The minimum modularity.
Lee, J S; Hwang, S; Yeo, J; Kim, D; Kahng, B
2014-11-01
A wide range of interacting systems can be described by complex networks. A common feature of such networks is that they consist of several communities or modules, the degree of which may quantified as the modularity. However, even a random uncorrelated network, which has no obvious modular structure, has a finite modularity due to the quenched disorder. For this reason, the modularity of a given network is meaningful only when it is compared with that of a randomized network with the same degree distribution. In this context, it is important to calculate the modularity of a random uncorrelated network with an arbitrary degree distribution. The modularity of a random network has been calculated [Reichardt and Bornholdt, Phys. Rev. E 76, 015102 (2007)PLEEE81539-375510.1103/PhysRevE.76.015102]; however, this was limited to the case whereby the network was assumed to have only two communities, and it is evident that the modularity should be calculated in general with q(≥2) communities. Here we calculate the modularity for q communities by evaluating the ground-state energy of the q-state Potts Hamiltonian, based on replica symmetric solutions assuming that the mean degree is large. We found that the modularity is proportional to 〈sqrt[k]〉/〈k〉 regardless of q and that only the coefficient depends on q. In particular, when the degree distribution follows a power law, the modularity is proportional to 〈k〉^{-1/2}. Our analytical results are confirmed by comparison with numerical simulations. Therefore, our results can be used as reference values for real-world networks.
Control of donor charge states with the tip of a scanning tunnelling microscope
Teichmann, K.; Wenderoth, M.; Loth, S.; Ulbrich, R.G. [IV. Physikalisches Institut, Georg-August-Universitaet Goettingen (Germany); Garlef, J.K.; Wijnheijmer, A.P.; Koenraad, P.M. [PSN, Eindhoven University of Technology (Netherlands)
2009-07-01
The functionality of nanoscale semiconductor devices crucially depends on details of the electrostatic potential landscape on the atomic scale and its microscopic response to external electric fields. We report here an investigation of charge state switching of buried single Si donors in 6.10{sup 18} cm{sup -3} n-doped GaAs with scanning tunnelling microscopy (STM) under UHV conditions at 5 K. The effect of tip induced band bending (TIBB) through the freshly cleaved (110)-surface was used to change the charge state of individual donors from neutral to positively charged and reverse. Scanning tunnelling spectroscopy (STS) revealed a ring like feature around each donor center. The ring radius depends on tip bias voltage. The charge state of each donor in the random arrangement of dopants was in most cases unambiguously fixed by the extension of the tip-induced space charge cloud, which was located under the tip and controlled by the applied voltage. For certain geometric configurations the system showed bi- (or multi-) stable behaviour, this lead to dynamic flickering of the ionization sequence.
Democratic Republic of Congo A Fertile Ground for Instability in the Great Lakes Region States
2017-06-09
DEMOCRATIC REPUBLIC OF CONGO-A FERTILE GROUND FOR INSTABILITY IN THE GREAT LAKES REGION STATES A thesis presented to the Faculty of...From - To) AUG 2016 – JUNE 2017 4. TITLE AND SUBTITLE Democratic Republic of Congo-A Fertile Ground for Instability in the Great Lakes Region ...caused instability and chaos in the eastern provinces of the Congo, known as the Great Lakes Region . The DRC holds a strategic geographical position
Sharma, Prashant
2015-01-01
Charge state distributions of $^{56}$Fe and $^{58}$Ni projectile ions passing through thin carbon foils have been studied in the energy range of 1.44 - 2.69 MeV/u using a novel method from the x-ray spectroscopy technique. Interestingly the charge state distribution in the bulk show Lorentzian behavior instead of usual Gaussian distribution. Further, different parameters of charge state distribution like mean charge state, distribution width and asymmetric parameter are determined and compared with the empirical calculations and ETACHA predictions. It is found that the x-ray measurement technique is appropriate to determine the mean charge state right at the interaction zone or in the bulk. Interestingly, empirical formalism predicts much lower projectile mean charge states compare to x-ray measurements which clearly indicate multi-electron capture from the target surface. The ETACHA predictions and experimental results are found to be comparable for energies $\\geq$ 2 MeV/u.
Chiral extrapolations and strangeness in the baryon ground states
Lutz, Matthias F M
2013-01-01
We review the quark-mass dependence of the baryon octet and decuplet masses as obtained from recent lattice simulations of the BMW, PACS-CS, LHPC, HSC and QCDSF-UKQCD groups. Our discussion relies on the relativistic chiral Lagrangian and large-$N_c$ sum rule estimates of the counter terms relevant for the baryon masses at N$^3$LO. A partial summation is implied by the use of physical baryon and meson masses in the one-loop contributions to the baryon self energies. In our analysis the physical masses are reproduced exactly by means of a suitable set of linear constraints. A quantitative and simultaneous description of all lattice results is achieved in terms of a six parameter fit, where the symmetry conserving counter term that are relevant at N$^3$LO are not yet being used. For pion masses larger than 300 MeV there appears to be an approximate linear pion-mass dependence of all octet and decuplet baryon masses. We discuss the pion- and strangeness sigma terms of the baryon octet states.
Demchenko, Alexander P; Tang, Kuo-Chun; Chou, Pi-Tai
2013-02-01
Charge and proton transfer reactions in the excited states of organic dyes can be coupled in many different ways. Despite the complementarity of charges, they can occur on different time scales and in different directions of the molecular framework. In certain cases, excited-state equilibrium can be established between the charge-transfer and proton-transfer species. The interplay of these reactions can be modulated and even reversed by variations in dye molecular structures and changes of the surrounding media. With knowledge of the mechanisms of these processes, desired rates and directions can be achieved, and thus the multiple emission spectral features can be harnessed. These features have found versatile applications in a number of cutting-edge technological areas, particularly in fluorescence sensing and imaging.
Performance on the low charge state laser ion source in BNL
Okamura, M.; Alessi, J.; Beebe, E.; Costanzo, M.; DeSanto, L.; Jamilkowski, J.; Kanesue, T.; Lambiase, R.; Lehn, D.; Liaw, C. J.; McCafferty, D.; Morris, J.; Olsen, R.; Pikin, A.; Raparia, D.; Steszyn, A.; Ikeda, S.
2015-09-07
On March 2014, a Laser Ion Source (LIS) was commissioned which delivers high-brightness, low-charge-state heavy ions for the hadron accelerator complex in Brookhaven National Laboratory (BNL). Since then, the LIS has provided many heavy ion species successfully. The low-charge-state (mostly singly charged) beams are injected to the Electron Beam Ion Source (EBIS), where ions are then highly ionized to fit to the following accelerator’s Q/M acceptance, like Au^{32+}. Recently we upgraded the LIS to be able to provide two different beams into EBIS on a pulse-to-pulse basis. Now the LIS is simultaneously providing beams for both the Relativistic Heavy Ion Collider (RHIC) and NASA Space Radiation Laboratory (NSRL).
Zeng, Zebing; Lee, Sangsu; Son, Minjung; Fukuda, Kotaro; Burrezo, Paula Mayorga; Zhu, Xiaojian; Qi, Qingbiao; Li, Run-Wei; Navarrete, Juan T López; Ding, Jun; Casado, Juan; Nakano, Masayoshi; Kim, Dongho; Wu, Jishan
2015-07-08
Research on stable open-shell singlet diradicaloids recently became a hot topic because of their unique optical, electronic, and magnetic properties and promising applications in materials science. So far, most reported singlet diradicaloid molecules have a symmetric structure, while asymmetric diradicaloids with an additional contribution of a dipolar zwitterionic form to the ground state were rarely studied. In this Article, a series of new push-pull type oligo(N-annulated perylene)quinodimethanes were synthesized. Their chain length and solvent-dependent ground states and physical properties were systematically investigated by various experimental methods such as steady-state and transient absorption, two-photon absorption, X-ray crystallographic analysis, electron spin resonance, superconducting quantum interference device, Raman spectroscopy, and electrochemistry. It was found that with extension of the chain length, the diradical character increases while the contribution of the zwitterionic form to the ground state becomes smaller. Because of the intramolecular charge transfer character, the physical properties of this push-pull system showed solvent dependence. In addition, density functional theory calculations on the diradical character and Hirshfeld charge were conducted to understand the chain length and solvent dependence of both symmetric and asymmetric systems. Our studies provided a comprehensive understanding on the fundamental structure- and environment-property relationships in the new asymmetric diradicaloid systems.
Joshi, Sunita; Pant, Debi D.
2012-06-01
Ground and excited state dipole moments of probe quinine sulphate (QS) was obtained using Solvatochromic shift method. Higher dipole moment is observed for excited state as compared to the ground state which is attributed to the higher polarity of excited state.
Dissociation of charge-transfer states at donor-acceptor interfaces of organic heterojunctions
Inche Ibrahim, M. L.
2017-02-01
The dissociation of charge-transfer (CT) states into free charge carriers at donor-acceptor (DA) interfaces is an important step in the operation of organic solar cells and related devices. In this paper, we show that the effect of DA morphology and architecture means that the directions of CT states (where a CT state’s direction is defined as the direction from the electron to the hole of the CT state) may deviate from the direction of the applied electric field. The deviation means that the electric field is not fully utilized to assist, and could even hinder the dissociation process. Furthermore, we show that the correct charge carrier mobilities that should be used to describe CT state dissociation are the actual mobilites at DA interfaces. The actual mobilities are defined in this paper, and in general are not the same as the mobilities that are used to calculate electric currents which are the mobilites along the direction of the electric field. Then, to correctly describe CT state dissociation, we modify the widely used Onsager-Braun (OB) model by including the effect of DA morphology and architecture, and by employing the correct mobilities. We verify that when the modified OB model is used to describe CT state dissociation, the fundamental issues that concern the original OB model are resolved. This study demonstrates that DA morphology and architecture play an important role by strongly influencing the CT state dissociation as well as the mobilites along the direction of the electric field.
Structural Distortion Stabilizing the Antiferromagnetic and Semiconducting Ground State of BaMn2As2
Ekkehard Krüger
2016-09-01
Full Text Available We report evidence that the experimentally found antiferromagnetic structure as well as the semiconducting ground state of BaMn 2 As 2 are caused by optimally-localized Wannier states of special symmetry existing at the Fermi level of BaMn 2 As 2 . In addition, we find that a (small tetragonal distortion of the crystal is required to stabilize the antiferromagnetic semiconducting state. To our knowledge, this distortion has not yet been established experimentally.
Van der Waals potential and vibrational energy levels of the ground state radon dimer
Sheng, Xiaowei; Qian, Shifeng; Hu, Fengfei
2017-08-01
In the present paper, the ground state van der Waals potential of the Radon dimer is described by the Tang-Toennies potential model, which requires five essential parameters. Among them, the two dispersion coefficients C6 and C8 are estimated from the well determined dispersion coefficients C6 and C8 of Xe2. C10 is estimated by using the approximation equation that C6C10 / C82 has an average value of 1.221 for all the rare gas dimers. With these estimated dispersion coefficients and the well determined well depth De and Re the Born-Mayer parameters A and b are derived. Then the vibrational energy levels of the ground state radon dimer are calculated. 40 vibrational energy levels are observed in the ground state of Rn2 dimer. The last vibrational energy level is bound by only 0.0012 cm-1.
Evidence for a gapped spin-liquid ground state in a kagome Heisenberg antiferromagnet.
Fu, Mingxuan; Imai, Takashi; Han, Tian-Heng; Lee, Young S
2015-11-06
The kagome Heisenberg antiferromagnet is a leading candidate in the search for a spin system with a quantum spin-liquid ground state. The nature of its ground state remains a matter of active debate. We conducted oxygen-17 single-crystal nuclear magnetic resonance (NMR) measurements of the spin-1/2 kagome lattice in herbertsmithite [ZnCu3(OH)6Cl2], which is known to exhibit a spinon continuum in the spin excitation spectrum. We demonstrated that the intrinsic local spin susceptibility χ(kagome), deduced from the oxygen-17 NMR frequency shift, asymptotes to zero below temperatures of 0.03J, where J ~ 200 kelvin is the copper-copper superexchange interaction. Combined with the magnetic field dependence of χ(kagome) that we observed at low temperatures, these results imply that the kagome Heisenberg antiferromagnet has a spin-liquid ground state with a finite gap.
Tree based machine learning framework for predicting ground state energies of molecules
Himmetoglu, Burak
2016-10-01
We present an application of the boosted regression tree algorithm for predicting ground state energies of molecules made up of C, H, N, O, P, and S (CHNOPS). The PubChem chemical compound database has been incorporated to construct a dataset of 16 242 molecules, whose electronic ground state energies have been computed using density functional theory. This dataset is used to train the boosted regression tree algorithm, which allows a computationally efficient and accurate prediction of molecular ground state energies. Predictions from boosted regression trees are compared with neural network regression, a widely used method in the literature, and shown to be more accurate with significantly reduced computational cost. The performance of the regression model trained using the CHNOPS set is also tested on a set of distinct molecules that contain additional Cl and Si atoms. It is shown that the learning algorithms lead to a rich and diverse possibility of applications in molecular discovery and materials informatics.
Tree based machine learning framework for predicting ground state energies of molecules
Himmetoglu, Burak
2016-01-01
We present an application of the boosted regression tree algorithm for predicting ground state energies of molecules made up of C, H, N, O, P, and S (CHNOPS). The PubChem chemical compound database has been incorporated to construct a dataset of 16,242 molecules, whose electronic ground state energies have been computed using density functional theory. This dataset is used to train the boosted regression tree algorithm, which allows a computationally efficient and accurate prediction of molecular ground state energies. Predictions from boosted regression trees are compared with neural network regression, a widely used method in the literature, and shown to be more accurate with significantly reduced computational cost. The performance of the regression model trained using the CHNOPS set is also tested on a set of distinct molecules that contain additional Cl and Si atoms. It is shown that the learning algorithms lead to a rich and diverse possibility of applications in molecular discovery and materials inform...
Kalman-variant estimators for state of charge in lithium-sulfur batteries
Propp, Karsten; Auger, Daniel J.; Fotouhi, Abbas
2017-01-01
Lithium-sulfur batteries are now commercially available, offering high specific energy density, low production costs and high safety. However, there is no commercially-available battery management system for them, and there are no published methods for determining state of charge in situ. This pa...
Zheng, Zilong
2017-05-08
We investigate the impact of electronic polarization, charge delocalization, and energetic disorder on the charge-transfer (CT) states formed at a planar C60/pentacene interface. The ability to examine large complexes containing up to seven pentacene molecules and three C60 molecules allows us to take explicitly into account the electronic polarization effects. These complexes are extracted from a bilayer architecture modeled by molecular dynamics simulations and evaluated by means of electronic-structure calculations based on long-range-separated functionals (ωB97XD and BNL) with optimized range-separation parameters. The energies of the lowest charge-transfer states derived for the large complexes are in very good agreement with the experimentally reported values. The average singlet-triplet energy splittings of the lowest CT states are calculated not to exceed 10 meV. The rates of geminate recombination as well as of dissociation of the triplet excitons are also evaluated. In line with experiment, our results indicate that the pentacene triplet excitons generated through singlet fission can dissociate into separated charges on a picosecond time scale, despite the fact that their energy in C60/pentacene heterojunctions is slightly lower than the energies of the lowest CT triplet states.
Observation of High Iron Charge States at Low Energies in Solar Energetic Particle Events
Guo, Z.; Möbius, E.; Klecker, B.; Bochsler, P.; Connell, J. J.; Kartavykh, Y. Y.; Mason, G. M.; Popecki, M. A.
2014-04-01
The ionic charge states of solar energetic particles (SEPs) provide direct information about the source plasma, the acceleration environment, and their transport. Recent studies report that both gradual and impulsive SEP events show mean iron charge states langQ Ferang ~ 10-14 at low energies E nuc-1, consistent with their origin from typical corona material at temperatures 1-2 MK. Observed increases of langQ Ferang up to 20 at energies 0.1-0.5 MeV nuc-1 in impulsive SEPs are attributed to stripping during acceleration. However, Q Fe > 16 is occasionally found in the solar wind, particularly coming from active regions, in contrast to the exclusively reported langQ Ferang = 14 throughout the entire SEPICA and STOF energy range have been identified. Four of the nine events are impulsive events identified through velocity dispersion that are consistent with source temperatures >=2 MK up to ~4 MK. The other five events show evidence of interplanetary acceleration. Four of them involve re-acceleration of impulsive material, whose original energy dependent charge states appear re-distributed to varying extent bringing higher charge states to lower energy. One event, which shows flat but elevated langQ Ferang ~ 14.2 over the entire energy range, can be associated with interplanetary acceleration of high temperature material. This event may exemplify a rare situation when a second shock plows through high temperature coronal mass ejection material.
Spectroscopy of charge transfer states in Mg1 - x Ni x O
Churmanov, V. N.; Sokolov, V. I.; Pustovarov, V. A.; Gruzdev, N. B.; Mironova-Ulmane, N.
2016-10-01
Photoluminescence and photoluminescence excitation spectra of solid solution Mg1- x Ni x O ( x = 0.008) have been analyzed. The contributions of charge transfer electronic states and nonradiative Auger relaxation to the formation of the photoluminescence spectrum are discussed.
2010-10-01
... 42 Public Health 4 2010-10-01 2010-10-01 false Alternative copayments, coinsurance, deductibles, or similar cost sharing charges: State plan requirements. 447.68 Section 447.68 Public Health CENTERS... Under Section 1916a § 447.68 Alternative copayments, coinsurance, deductibles, or similar cost...
Smart and Accurate State-of-Charge Indication in Portable Applications
Pop, V.; Bergveld, H.J.; Notten, P.H.L.; Regtien, P.P.L.
2005-01-01
Accurate State-of-Charge (SoC) and remaining run-time indication for portable devices is important for the user-convenience and to prolong the lifetime of batteries. However, the known methods of SoC indication in portable applications are not accurate enough under all practical conditions. The meth
Robust Battery Fuel Gauge Algorithm Development, Part 3: State of Charge Tracking
2014-10-19
parameters are obtained by performing an OCV test on a Samsung battery (with serial number EB575152). This resulted in the following values for the...Industrial Electronics , IEEE Transactions on, vol. 57, no. 12, pp. 4178–4187, 2010. [12] S. Chen, Y. Fu, and C. Mi, “State of charge estimation of
Measurement of the charging state of 4-70 nm aerosols
Enghoff, Martin Andreas Bødker; Svensmark, Jacob
2017-01-01
The charging state of aerosols in an 8 m3 reaction chamber was measured using an electrostatic classifier with a condensation particle counter at different levels of ionization in the chamber. By replacing the Kr-85 neutralizer in the classifier with a radioactively neutral dummy we were able...
Symmetry-breaking intramolecular charge transfer in the excited state of meso-linked BODIPY dyads
Whited, Matthew T.
2012-01-01
We report the synthesis and characterization of symmetric BODIPY dyads where the chromophores are attached at the meso position, using either a phenylene bridge or direct linkage. Both molecules undergo symmetry-breaking intramolecular charge transfer in the excited state, and the directly linked dyad serves as a visible-light-absorbing analogue of 9,9′-bianthryl.
A Real-Time evaluation system for a state-of-charge indication algorithm
Pop, V.; Bergveld, H.J.; Notten, P.H.L.; Regtien, Paulus P.L.
2005-01-01
The known methods of State-of-Charge (SoC) indication in portable applications are not accurate enough under all practical conditions. This paper describes a real- time evaluation LabVIEW system for an SoC algorithm, that calculates the SoC in [%] and also the remaining run-time available under the
A Real-Time evaluation system for a state-of-charge indication algorithm
Pop, V.; Bergveld, H.J.; Notten, P.H.L.; Regtien, P.P.L.
2005-01-01
The known methods of State-of-Charge (SoC) indication in portable applications are not accurate enough under all practical conditions. This paper describes a real- time evaluation LabVIEW system for an SoC algorithm, that calculates the SoC in [%] and also the remaining run-time available under the
Khuyagbaatar, J.; Shevelko, V. P.; Borschevsky, A.; Duellmann, Ch. E.; Tolstikhina, I. Yu.; Yakushev, A.
2013-01-01
The average charge states (q) over bar of heavy and superheavy ions (atomic numbers Z = 80-114) passing through He gas are studied experimentally and theoretically. Experimental data were measured at the gas-filled recoil separator, i.e., the TransActinide Separator and Chemistry Apparatus (TASCA) a
Tracking excited-state charge and spin dynamics in iron coordination complexes
Zhang, Wenkai; Alonso-Mori, Roberto; Bergmann, Uwe
2014-01-01
to spin state, can elucidate the spin crossover dynamics of [Fe(2,2'-bipyridine)(3)](2+) on photoinduced metal-to-ligand charge transfer excitation. We are able to track the charge and spin dynamics, and establish the critical role of intermediate spin states in the crossover mechanism. We anticipate......Crucial to many light-driven processes in transition metal complexes is the absorption and dissipation of energy by 3d electrons(1-4). But a detailed understanding of such non-equilibrium excited-state dynamics and their interplay with structural changes is challenging: a multitude of excited...... states and possible transitions result in phenomena too complex to unravel when faced with the indirect sensitivity of optical spectroscopy to spin dynamics(5) and the flux limitations of ultrafast X-ray sources(6,7). Such a situation exists for archetypal poly-pyridyl iron complexes, such as [Fe(2...
Hybrid fuzzy charged system search algorithm based state estimation in distribution networks
Sachidananda Prasad
2017-06-01
Full Text Available This paper proposes a new hybrid charged system search (CSS algorithm based state estimation in radial distribution networks in fuzzy framework. The objective of the optimization problem is to minimize the weighted square of the difference between the measured and the estimated quantity. The proposed method of state estimation considers bus voltage magnitude and phase angle as state variable along with some equality and inequality constraints for state estimation in distribution networks. A rule based fuzzy inference system has been designed to control the parameters of the CSS algorithm to achieve better balance between the exploration and exploitation capability of the algorithm. The efficiency of the proposed fuzzy adaptive charged system search (FACSS algorithm has been tested on standard IEEE 33-bus system and Indian 85-bus practical radial distribution system. The obtained results have been compared with the conventional CSS algorithm, weighted least square (WLS algorithm and particle swarm optimization (PSO for feasibility of the algorithm.
Fourier-transform spectroscopy of Sr2 and revised ground-state potential
Stein, A.; Knöckel, H.; Tiemann, E.
2008-10-01
Precise potentials for the ground-state XΣg+1 and the minimum region of the excited state 2Σu+1 of Sr2 are derived by high-resolution Fourier-transform spectroscopy of fluorescence progressions from single-frequency laser excitation of Sr2 produced in a heat pipe at 950°C . A change of the rotational assignment by four units compared to an earlier work [G. Gerber , J. Chem. Phys. 81, 1538 (1984)] is needed for a consistent description leading to a significant shift of the potentials toward longer interatomic distances. The huge amount of ground-state data derived for the three different isotopomers Sr288 , Sr86Sr88 , and Sr87Sr88 (almost 60% of all excisting bound rovibrational ground-state levels for the isotopomer Sr288 ) fixes this assignment beyond a doubt. The presented ground-state potential is derived from the observed transitions for the radial region from 4to11Å ( 9cm-1 below the asymptote) and is extended to the long-range region by the use of theoretical dispersion coefficients together with already available photoassociation data. New estimations of the scattering lengths for the complete set of isotopic combinations are derived by mass scaling with the derived potential. The data set for the excited state 2Σu+1 was sufficient to derive a potential energy curve around the minimum.
Kohn, W.
1983-01-01
It is shown that if n(r) is the discrete density on a lattice (enclosed in a finite box) associated with a nondegenerate ground state in an external potential v(r) (i.e., is 'v-representable'), then the density n(r) + mu(r), with m(r) arbitrary (apart from trivial constraints) and mu small enough, is also associated with a nondegenerate ground state in an external potential v'(r) near v(r); i.e., n(r) + m(r) is also v-representable. Implications for the Hohenberg-Kohn variational principle and the Kohn-Sham equations are discussed.
First-principles prediction of a ground state crystal structure of magnesium borohydride.
Ozolins, V; Majzoub, E H; Wolverton, C
2008-04-04
Mg(BH(4))(2) contains a large amount of hydrogen by weight and by volume, but its promise as a candidate for hydrogen storage is dependent on the currently unknown thermodynamics of H2 release. Using first-principles density-functional theory calculations and a newly developed prototype electrostatic ground state search strategy, we predict a new T=0 K ground state of Mg(BH(4))(2) with I4[over ]m2 symmetry, which is 5 kJ/mol lower in energy than the recently proposed P6(1) structure. The calculated thermodynamics of H(2) release are within the range required for reversible storage.
Ground state atomic oxygen in high-power impulse magnetron sputtering: a quantitative study
Britun, Nikolay; Belosludtsev, Alexandr; Silva, Tiago; Snyders, Rony
2017-02-01
The ground state density of oxygen atoms in reactive high-power impulse magnetron sputtering discharges has been studied quantitatively. Both time-resolved and space-resolved measurements were conducted. The measurements were performed using two-photon absorption laser-induced fluorescence (TALIF), and calibrated by optical emission actinometry with multiple Ar emission lines. The results clarify the dynamics of the O ground state atoms in the discharge afterglow significantly, including their propagation and fast decay after the plasma pulse, as well as the influence of gas pressure, O2 admixture, etc.
Preparing ground States of quantum many-body systems on a quantum computer.
Poulin, David; Wocjan, Pawel
2009-04-03
Preparing the ground state of a system of interacting classical particles is an NP-hard problem. Thus, there is in general no better algorithm to solve this problem than exhaustively going through all N configurations of the system to determine the one with lowest energy, requiring a running time proportional to N. A quantum computer, if it could be built, could solve this problem in time sqrt[N]. Here, we present a powerful extension of this result to the case of interacting quantum particles, demonstrating that a quantum computer can prepare the ground state of a quantum system as efficiently as it does for classical systems.
Traces of Lorentz symmetry breaking in a hydrogen atom at ground state
Borges, L. H. C.; Barone, F. A.
2016-02-01
Some traces of a specific Lorentz symmetry breaking scenario in the ground state of the hydrogen atom are investigated. We use standard Rayleigh-Schrödinger perturbation theory in order to obtain the corrections to the ground state energy and the wave function. It is shown that an induced four-pole moment arises, due to the Lorentz symmetry breaking. The model considered is the one studied in Borges et al. (Eur Phys J C 74:2937, 2014), where the Lorentz symmetry is broken in the electromagnetic sector.
Ub-library of Atomic Masses and Nuclear Ground States Deformations (CENPL.AMD)
2001-01-01
The atomic mass is one of basic data of a nuclear. There are the atomic masses in all nuclear reaction model formulas and motion equations. For any reaction calculations atomic masses are basic data for getting binding energies or Q-values. In some applications, it is important also to have atomic masses even for exotic nuclei quite far from the valley of stability. In addition, nuclear ground state deformations and abundance values are also requisite in the nuclear data calculations. For this purpose, A data file on atomic masses and nuclear ground states deformations (AMD) were constructed, which
Expectation values of single-particle operators in the random phase approximation ground state
Kosov, Daniel S
2016-01-01
We developed a method for computing matrix elements of single-particle operators in the correlated random phase approximation ground state. Working with the explicit random phase approximation ground state wavefunction, we derived practically useful and simple expression for a molecular property in terms of random phase approximation amplitudes. The theory is illustrated by the calculation of molecular dipole moments. It is shown that Hartree-Fock based random phase approximation provides a systematic improvement of molecular dipole moment values in comparison to M{\\o}ller-Plesset second order perturbation theory and coupled cluster method for a considered set of molecules.
Stability of the electroweak ground state in the Standard Model and its extensions
Luca Di Luzio
2016-02-01
Full Text Available We review the formalism by which the tunnelling probability of an unstable ground state can be computed in quantum field theory, with special reference to the Standard Model of electroweak interactions. We describe in some detail the approximations implicitly adopted in such calculation. Particular attention is devoted to the role of scale invariance, and to the different implications of scale-invariance violations due to quantum effects and possible new degrees of freedom. We show that new interactions characterized by a new energy scale, close to the Planck mass, do not invalidate the main conclusions about the stability of the Standard Model ground state derived in absence of such terms.
Traces of Lorentz symmetry breaking in a Hydrogen atom at ground state
Borges, Luiz Henrique de Campos
2016-01-01
Some traces of a specific Lorentz symmetry breaking scenario in the ground state of the Hydrogen atom are investigated. It is used standard Rayleigh-Schr\\"odinger perturbation theory in order to obtain the corrections to the the ground state energy and wave function. It is shown that an induced four-pole moment arises, due to the Lorentz symmetry breaking. The model considered is the one studied in reference Eur. Phys. J. C {\\bf 74}, 2937 (2014), where the Lorentz symmetry is broken in the electromagnetic sector.
Boundedness and convergence of perturbed corrections for helium-like ions in ground states
Zhao Yun-Hui; Hai Wen-Hua; Zhao Cheng-Lin; Luo Xiao-Bing
2008-01-01
Applying the improved Rayleigh-Schr(o)dinger perturbation theory based on an integral equation to helium-like ions in ground states and treating electron correlations as perturbations,we obtain the second-order corrections to wavefunctions consisting of a few terms and the third-order corrections to energicity.It is demonstrated that the corrected wavefunctions are bounded and quadratically integrable,and the corresponding perturbation series is convergent.The results clear off the previous distrust for the convergence in the quantum perturbation theory and show a reciprocal development on the quantum perturbation problem of the ground state helium-like systems.
Singlet Ground State Magnetism: III Magnetic Excitons in Antiferromagnetic TbP
Knorr, K.; Loidl, A.; Kjems, Jørgen
1981-01-01
The dispersion of the lowest magnetic excitations of the singlet ground state system TbP has been studied in the antiferromagnetic phase by inelastic neutron scattering. The magnetic exchange interaction and the magnetic and the rhombohedral molecular fields have been determined.......The dispersion of the lowest magnetic excitations of the singlet ground state system TbP has been studied in the antiferromagnetic phase by inelastic neutron scattering. The magnetic exchange interaction and the magnetic and the rhombohedral molecular fields have been determined....
Ground State Properties of Superheavy Nuclei in Macroscopic-Microscopic Model
ZHI Qi-Jun; REN Zhong-Zhou; ZHANG Xiao-Ping; ZHENG Qiang
2008-01-01
The ground state properties of superheavy nuclei are systematically calculated by the macroscopic-microscopic (MM) model with the Nilsson potential The calculations well produced the ground state binding energies,a-decay energies,and half lives of superheavy nuclei.The calculated results are systematically compared with available experimental data.The calculated results are also compared with theoretical results from other MM models and from relativistic mean-field model.The calculations and comparisons show that the MM model is reliable in superheavy region and that the MM model results are not very sensitive to the choice of microscopic single-particle potential.
Traces of Lorentz symmetry breaking in a hydrogen atom at ground state
Borges, L.H.C. [Universidade Federal do ABC, Centro de Ciencias Naturais e Humanas, Santo Andre, SP (Brazil); Barone, F.A. [IFQ-Universidade Federal de Itajuba, Itajuba, MG (Brazil)
2016-02-15
Some traces of a specific Lorentz symmetry breaking scenario in the ground state of the hydrogen atom are investigated. We use standard Rayleigh-Schroedinger perturbation theory in order to obtain the corrections to the ground state energy and the wave function. It is shown that an induced four-pole moment arises, due to the Lorentz symmetry breaking. The model considered is the one studied in Borges et al. (Eur Phys J C 74:2937, 2014), where the Lorentz symmetry is broken in the electromagnetic sector. (orig.)
Duan, Wenye; Wang, Wei; Zhang, Chao; Jin, Kuijuan; Ma, Zhongshui
2016-10-01
The proximity properties of edge currents in the vicinity of the interface between the graphene and superconductor in the presence of magnetic field are investigated. It is shown that the edge states introduced by Andreev reflection at the graphene-superconductor (G/S) interface give rise to the charge neutral states in all Landau levels. We note that in a topological insulator-superconductor (TI/S) hybrid structure, only N = 0 Landau level can support this type of charge neutral states. The different interface states of a G/S hybrid and a TI/S hybrid is due to that graphene consists of two distinct sublattices. The armchair edge consists of two inequivalent atoms. This gives rise to unique electronic properties of edge states when connected to a superconductor. A direct consequence of zero charge states in all Landau levels is that the current density approaches zero at interface. The proximity effect leads to quantum magnetic oscillation of the current density in the superconductor region. The interface current density can also be tuned with a finite interface potential. For sharp δ-type interface potential, the derivative of the wavefunction is discontinuous. As a result, we found that there is current density discontinuity at the interface. The step of the current discontinuity is proportional to the strength of the interface potential.
Nakata, Hiroya, E-mail: nakata.h.ab@m.titech.ac.jp [Center for Biological Resources and Informatics, Tokyo Institute of Technology, B-62 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8501 (Japan); RIKEN, Research Cluster for Innovation, Nakamura Lab, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Fedorov, Dmitri G. [NRI, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568 (Japan); Yokojima, Satoshi [RIKEN, Research Cluster for Innovation, Nakamura Lab, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Tokyo University of Pharmacy and Life Sciences, 1423-1 Horinouchi, Hachioji-shi, Tokyo 192-0392 (Japan); Kitaura, Kazuo [Graduate School of System Informatics, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe 657-8501 (Japan); Sakurai, Minoru [Center for Biological Resources and Informatics, Tokyo Institute of Technology, B-62 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8501 (Japan); Nakamura, Shinichiro [RIKEN, Research Cluster for Innovation, Nakamura Lab, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan)
2014-04-14
We extended the fragment molecular orbital (FMO) method interfaced with density functional theory (DFT) into spin unrestricted formalism (UDFT) and developed energy gradients for the ground state and single point excited state energies based on time-dependent DFT. The accuracy of FMO is evaluated in comparison to the full calculations without fragmentation. Electronic excitations in solvated organic radicals and in the blue copper protein, plastocyanin (PDB code: 1BXV), are reported. The contributions of solvent molecules to the electronic excitations are analyzed in terms of the fragment polarization and quantum effects such as interfragment charge transfer.
Influence of charge transfer state on Eu3+ luminescence in LaAlO3, by high pressure spectroscopy
Behrendt, Mirosław; Mahlik, Sebastian; Grinberg, Marek; Stefańska, Dagmara; Dereń, Przemysław J.
2017-01-01
The contribution presents spectroscopic characterization of LaAlO3 doped with 0.5 mol %. Eu3+. We measured steady state luminescence, luminescence excitation spectra, as well as the time resolved spectra and luminescence kinetics. The experiments were performed at high hydrostatic pressure applied in diamond anvil cell (DAC) which was changed from ambient to 250 kbar. We found that for all pressures the emission from the 5D0 and 5D1 excited emitting state of Eu3+ was delayed in time after excitation pulse whilst emission from the 5D2 appear immediately after excitation. At pressure above 12 kbar the strong magnification of the luminescence lines related to the transitions from the 5D3 state which were very weak at ambient condition is observed. The emission decay of the 5D3 luminescence become slower when pressure is increased. All these effects are attributed to pressure-induced increase of the energy of the ground electronic configuration 4f6 of the Eu2+ with respect to the valence band edge which results in the charge transfer state, and 5D3 level crossing.
Structure and analytical potential energy function for the ground state of the BCx (x=0, -1)
Geng Zhen-Duo; Zhang Yan-Song; Fan Xiao-Wei; Lu Zhan-Sheng; Luo Gai-Xia
2006-01-01
In this paper, the electronic states of the ground states and dissociation limits of BC and BC- are correctly determined based on group theory and atomic and molecular reaction statics. The equilibrium geometries, harmonic frequencies and dissociation energies of the ground state of BC and BC- are calculated by using density function theory and quadratic CI method including single and double substitutions. The analytical potential energy functions of these states have been fitted with Murrell-Sorbie potential energy function from our ab initio calculation results. The spectroscopic data (αe, ωe and ωeXe) of each state is calculated via the relation between analytical potential energy function and spectroscopic data. All the calculations are in good agreement with the experimental data.
Charge States of Solar Cosmic Rays and Constraints on Acceleration Times and Coronal Transport
Ruffolo, D
1997-01-01
We examine effects on the charge states of energetic ions associated with gradual solar flares due to shock heating and stripping at high ion velocities. Recent measurements of the mean charges of various elements after the flares of 1992 Oct 30 and 1992 Nov 2 allow one to place limits on the product of the electron density times the acceleration or coronal residence time. In particular, any residence in coronal loops must be for < 0.03 s, which rules out models of coronal transport in loops, such as the bird cage model. The results do not contradict models of shock acceleration of energetic ions from coronal plasma at various solar longitudes.
Equation of state for charge-doping-induced deformation and hardening in cubic crystals
Li, Yao; Liu, Xiaofei; Guo, Wanlin
2017-08-01
Charge doping would inevitably induce strain, which can significantly influence device performance but cannot be directly predicted by classical mechanical laws. Here we present a set of equations of states for deformable cubic crystals subjected to charge doping by introducing the quantum electronic stress at fixed lattice as equivalent mechanical pressure into the classical hydrostatic pressure-vs-deformation equations. The equations are proved to be efficient for all the cubic crystals considered in this work (diamond, Si, Ge, GaAs, Al, and ZrO2) by first-principles calculations. The proposed method and presented equations should pave a convenient way to predict doping effects on device performance.
Theoretical Studies on Thermal Decomposition of Benzoyl Peroxide in Ground State
SUN Cheng-ke; YANG Si-ya; LIN Xue-fei; MA Si-yu; LI Zong-he
2003-01-01
Systematic studies of the thermal decomposition mechanism of benzoyl peroxide(BPO) in ground state, leading to various intermediates, products and the potential energy surface(PES) of possible dissociation reactions were made computationally. The structures of the transition states and the activation energies for all the paths causing the formation of the reaction products mentioned above were calculated by the AM1 semi-empirical method. This method is shown to to be one predict correctly the preferred pathway for the title reaction. It has been found that in ground state, the thermal decomposition of benzoyl peroxide has two kinds of paths. The first pathway PhC(O)O-OC(O)Ph→PhC(O)O*→Ph*+CO2 produces finally phenyl radicals and carbon dioxide. And the second pathway PhC(O)OO-C(O)Ph→PhC(O)OO*+PhC(O)*→PhC(O)*+O2→Ph*+CO+O2, via which the reaction takes place only in two steps, produces oxygen and PhC(O)* radicals, and the further thermal dissociation of PhC(O)* is quite difficult because of the high activation energy in ground state. The calculated activation energies and reaction enthalpies are in good agreement with the experimental values. The research results also show that also the thermal dissociation process of the two bonds or the three bonds for the benzoyl peroxide doesn′t take place in ground state.
Seif, W M; Refaie, A I
2015-01-01
The ground-state spin and parity of a formed daughter in the radioactive Alpha-emitter is expected to influence the preformation probability of the Alpha and daughter clusters inside it. We investigate the Alpha and daughter preformation probability inside odd-A and doubly-odd radioactive nuclei when the daughter and parent are of different spin and/or parity. We consider only the ground-state to ground-state unfavored decays. This is to extract precise information about the effect of the difference in the ground states spin-parity of the involved nuclei far away any influences from the excitation energy if the decays are coming from isomeric states. The calculations are done for 161 Alpha-emitters, with Z=65-112 and N=84-173, in the framework of the extended cluster model, with WKB penetrability and assault frequency. We used a Hamiltonian energy density scheme based on Skyrme-SLy4 interaction to compute the interaction potential. The Alpha plus cluster preformation probability is extracted from the calculat...
Modeling of direct beam extraction for a high-charge-state fusion driver
Anderson, O. A.; Grant Logan, B.
A newly proposed type of multicharged ion source offers the possibility of an economically advantageous high-charge-state fusion driver. Multiphoton absorption in an intense uniform laser focus can give multiple charge states of high purity, simplifying or eliminating the need for charge-state separation downstream. Very large currents (hundreds of amperes) can be extracted from this type of source. Several arrangements are possible. For example, the laser plasma could be tailored for storage in a magnetic bucket, with beam extracted from the bucket. A different approach, described in this report, is direct beam extraction from the expanding laser plasma. We discuss extraction and focusing for the particular case of a 4.1 MV beam of Xe 16+ ions. The maximum duration of the beam pulse is limited by the total charge in the plasma, while the practical pulse length is determined by the range of plasma radii over which good beam optics can be achieved. The extraction electrode contains a solenoid for beam focusing. Our design studies were carried out first with an envelope code and then with a self-consistent particle code. Results from our initial model showed that hundreds of amperes could be extracted, but that most of this current missed the solenoid entrance or was intercepted by the wall and that only a few amperes were able to pass through. We conclude with an improved design which increases the surviving beam to more than 70 A.
Solar Energetic Particle drifts and the energy dependence of 1 AU charge states
Dalla, S; Battarbee, M
2016-01-01
The event-averaged charge state of heavy ion Solar Energetic Particles (SEPs), measured at 1 AU from the Sun, typically increases with the ions' kinetic energy. The origin of this behaviour has been ascribed to processes taking place within the acceleration region. In this paper we study the propagation through interplanetary space of SEP Fe ions, injected near the Sun with a variety of charge states that are uniformly distributed in energy, by means of a 3D test particle model. In our simulations, due to gradient and curvature drifts associated with the Parker spiral magnetic field, ions of different charge propagate with very different efficiencies to an observer that is not magnetically well connected to the source region. As a result we find that, for many observer locations, the 1 AU event-averaged charge state , as obtained from our model, displays an increase with particle energy E, in qualitative agreement with spacecraft observations. We conclude that drift-associated propagation is a possible explan...
Solar Energetic Particle Drifts and the Energy Dependence of 1 AU Charge States
Dalla, S.; Marsh, M. S.; Battarbee, M.
2017-01-01
The event-averaged charge state of heavy ion solar energetic particles (SEPs), measured at 1 au from the Sun, typically increases with the ions’ kinetic energy. The origin of this behavior has been ascribed to processes taking place within the acceleration region. In this paper we study the propagation through interplanetary space of SEP Fe ions, injected near the Sun with a variety of charge states that are uniformly distributed in energy, by means of a 3D test particle model. In our simulations, due to gradient and curvature drifts associated with the Parker spiral magnetic field, ions of different charge propagate with very different efficiencies to an observer that is not magnetically well connected to the source region. As a result we find that, for many observer locations, the 1 au event-averaged charge state , as obtained from our model, displays an increase with particle energy E, in qualitative agreement with spacecraft observations. We conclude that drift-associated propagation is a possible explanation for the observed distribution of versus E in SEP events, and that the distribution measured in interplanetary space cannot be taken to represent that at injection.
Full control of quadruple quantum dot circuit charge states in the single electron regime
Delbecq, M. R., E-mail: matthieu.delbecq@riken.jp; Nakajima, T.; Otsuka, T.; Amaha, S. [RIKEN, Center for Emergent Matter Science, 3-1 Wako-shi, Saitama 351-0198 (Japan); Watson, J. D. [Department of Physics, Purdue University, West Lafayette, Indiana 47907 (United States); Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907 (United States); Manfra, M. J. [Department of Physics, Purdue University, West Lafayette, Indiana 47907 (United States); Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907 (United States); School of Materials Engineering, Purdue University, West Lafayette, Indiana 47907 (United States); School of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47907 (United States); Tarucha, S. [RIKEN, Center for Emergent Matter Science, 3-1 Wako-shi, Saitama 351-0198 (Japan); Department of Applied Physics, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan)
2014-05-05
We report the realization of an array of four tunnel coupled quantum dots in the single electron regime, which is the first required step toward a scalable solid state spin qubit architecture. We achieve an efficient tunability of the system but also find out that the conditions to realize spin blockade readout are not as straightforwardly obtained as for double and triple quantum dot circuits. We use a simple capacitive model of the series quadruple quantum dots circuit to investigate its complex charge state diagrams and are able to find the most suitable configurations for future Pauli spin blockade measurements. We then experimentally realize the corresponding charge states with a good agreement to our model.
Charge states of a hydrogen defect (3326 cm{sup -1} line) in ZnO
Herklotz, Frank; Lavrov, Eduard; Weber, Joerg [Technische Universitaet Dresden (Germany)
2010-07-01
Hydrogen in ZnO is a common impurity that strongly influences its electrical and optical properties, in particular, via formation of shallow donor states. An IR absorption study of a H-related defect resulting in a local vibrational mode (LVM) at 3326 cm{sup -1} is presented. We observed that a sub band-gap illumination results in the appearance of an IR absorption line at 3358 cm{sup -1} at the expense of the 3326 cm{sup -1} signal. The results of isotope substitution experiments strongly reveal that the two signals are LVMs of the same defect in different charge states. From the energy of the sub band-gap light it is concluded that this defect has a deep level in the band-gap. Data on thermal stability as well as the transition between the different charge states at different temperatures are also presented. The microscopic nature of the defect is discussed.
Kálmán, Péter
2015-01-01
The features of electron assisted neutron exchange processes in crystalline solids are survayed. It is stated that, contrary to expectations, the cross section of these processes may reach an observable magnitude even in the very low energy case because of the extremely huge increment caused by the Coulomb factor of the electron assisted processes and by the effect of the crystal-lattice. The features of electron assisted heavy charged particle exchange processes, electron assisted nuclear capure processes and heavy charged particle assisted nuclear processes are also overviewed. Experimental observations, which may be related to our theoretical findings, are dealt with. The anomalous screening phenomenon is related to electron assisted neutron and proton exchange processes in crystalline solids. A possible explanation of observations by Fleischmann and Pons is presented. The possibility of the phenomenon of nuclear transmutation is qualitatively explained with the aid of usual and charged particle assisted r...
Charge states distribution of 3350 keV He ions channeled in silicon
Bentini, G G; Bianconi, M; Lotti, R; Lulli, G
2002-01-01
When an ion beam is aligned along a major crystalline axis the dominant interaction is with valence electrons. In this condition the charge exchange processes mostly concern the interaction between the incident ion and a quasi-free electron gas and a strong reduction of the charge-changing probabilities is expected. In this work, 3350 keV He sup + and He sup 2 sup + ions were aligned at small tilt angles about the axis of a 4650 A silicon crystalline membrane. The charge state distribution (CSD) of the transmitted ions was detected by an electro-magnetic analyzer having a very small acceptance angle. In these conditions the equilibration of the CSD was not yet reached and this allowed, making use of simple approximations, for the measurement of the valence electron loss cross-section.
The evolution of ion charge states in cathodic vacuum arc plasmas: a review
Anders, Andre
2011-12-18
Cathodic vacuum arc plasmas are known to contain multiply charged ions. 20 years after “Pressure Ionization: its role in metal vapour vacuum arc plasmas and ion sources” appeared in vol. 1 of Plasma Sources Science and Technology, it is a great opportunity to re-visit the issue of pressure ionization, a non-ideal plasma effect, and put it in perspective to the many other factors that influence observable charge state distributions, such as the role of the cathode material, the path in the density-temperature phase diagram, the “noise” in vacuum arc plasma as described by a fractal model approach, the effects of external magnetic fields and charge exchange collisions with neutrals. A much more complex image of the vacuum arc plasma emerges putting decades of experimentation and modeling in perspective.
Systematic study of α preformation probability of nuclear isomeric and ground states
Sun, Xiao-Dong; Wu, Xi-Jun; Zheng, Bo; Xiang, Dong; Guo, Ping; Li, Xiao-Hua
2017-01-01
In this paper, based on the two-potential approach combining with the isospin dependent nuclear potential, we systematically compare the α preformation probabilities of odd-A nuclei between nuclear isomeric states and ground states. The results indicate that during the process of α particle preforming, the low lying nuclear isomeric states are similar to ground states. Meanwhile, in the framework of single nucleon energy level structure, we find that for nuclei with nucleon number below the magic numbers, the α preformation probabilities of high-spin states seem to be larger than low ones. For nuclei with nucleon number above the magic numbers, the α preformation probabilities of isomeric states are larger than those of ground states. Supported by National Natural Science Foundation of China (11205083), Construct Program of Key Discipline in Hunan Province, Research Foundation of Education Bureau of Hunan Province, China (15A159), Natural Science Foundation of Hunan Province, China (2015JJ3103, 2015JJ2123), Innovation Group of Nuclear and Particle Physics in USC, Hunan Provincial Innovation Foundation for Postgraduate (CX2015B398)
Mukherjee, Sutirtha; Mandal, Sudhansu
The internal structure and topology of the ground states for fractional quantum Hall effect (FQHE) are determined by the relative angular momenta between all the possible pairs of electrons. Laughlin wave function is the only known microscopic wave function for which these relative angular momenta are homogeneous (same) for any pair of electrons and depend solely on the filling factor. Without invoking any microscopic theory, considering only the relationship between number of flux quanta and particles in spherical geometry, and allowing the possibility of inhomogeneous (different) relative angular momenta between any two electrons, we develop a general method for determining a closed-form ground state wave function for any incompressible FQHE state. Our procedure provides variationally obtained very accurate wave functions, yet having simpler structure compared to any other known complex microscopic wave functions for the FQHE states. This method, thus, has potential in predicting a very accurate ground state wave function for the puzzling states such as the state at filling fraction 5/2. We acknowledge support from Department of Science and Technology, India.
Singh Mehata, Mohan; Singh, Ajay K.; Sinha, Ravindra Kumar
2016-12-01
Optical absorption and fluorescence (FL) spectra of 2-, 6-, 7-, 8-hydroxyquinolines (2-,6-,7- and 8-HQs) have been measured at room temperature in the wide range of solvents of different polarities, dielectric constant and refractive index. The ground state dipole moment (µ g) and excited state dipole moment (µ e) of 2-, 6-, 7- and 8-HQs were obtained using solvatochromic shift (SS) methods and microscopic solvent polarity parameters (MSPP). Change in the dipole moment (Δµ) between the ground and photo-excited states was estimated from SS and MSPP methods. DFT and TDDFT based theoretical calculations were performed for the ground and excited states dipole moments, and for vertical transitions. A significant enhancement in the excited state dipole moment was observed following photo-excitation. The large value of Δµ clearly indicates to the charge-separation in the photo-excited states, which in turn depends on the position of the hydroxyl group in the ring.
Structures of 17F and 17O, 17Ne and 17N in the Ground State and the First Excited State
张虎勇; 沈文庆; 任中洲; 马余刚; 陈金根; 蔡翔舟; 卢照辉; 钟晨; 郭威; 魏义彬; 周星飞; 马国亮; 王鲲
2003-01-01
The structures of two couples of mirror nuclei 17 F and 17 O, 17 Ne and 17 N in the ground state and in the first excited state are investigated using the relativistic mean-field approach. Two-proton halo in 17Ne in the first excited state and in the ground state and two-neutron halo in 17N in the first excited state are suggested.Meanwhile, one-proton halo in 17 F in the first excited state and one-neutron halo in 17 O in the first excited state are also suggested. The skin structure appears in 17F and 17N in the ground state.
Dudley, G.; Mattle, T.
2011-10-01
Individual electrode EMFs of new and cycled Sony 18650 HC cells have been measured with the help of a lithium reference electrode inserted into complete cells. Results have revealed the relative contribution of each electrode to voltage hysteresis (the difference in cell EMF between charge and discharge at the same state of charge).They have also shown changes to the shape of the positive electrode EMF versus state of charge in cycled compared to beginning of life cells.
Generalized isotropic Lipkin-Meshkov-Glick models: ground state entanglement and quantum entropies
Carrasco, José A.; Finkel, Federico; González-López, Artemio; Rodríguez, Miguel A.; Tempesta, Piergiulio
2016-03-01
We introduce a new class of generalized isotropic Lipkin-Meshkov-Glick models with \\text{su}(m+1) spin and long-range non-constant interactions, whose non-degenerate ground state is a Dicke state of \\text{su}(m+1) type. We evaluate in closed form the reduced density matrix of a block of L spins when the whole system is in its ground state, and study the corresponding von Neumann and Rényi entanglement entropies in the thermodynamic limit. We show that both of these entropies scale as alog L when L tends to infinity, where the coefficient a is equal to (m - k)/2 in the ground state phase with k vanishing \\text{su}(m+1) magnon densities. In particular, our results show that none of these generalized Lipkin-Meshkov-Glick models are critical, since when L\\to ∞ their Rényi entropy R q becomes independent of the parameter q. We have also computed the Tsallis entanglement entropy of the ground state of these generalized \\text{su}(m+1) Lipkin-Meshkov-Glick models, finding that it can be made extensive by an appropriate choice of its parameter only when m-k≥slant 3 . Finally, in the \\text{su}(3) case we construct in detail the phase diagram of the ground state in parameter space, showing that it is determined in a simple way by the weights of the fundamental representation of \\text{su}(3) . This is also true in the \\text{su}(m+1) case; for instance, we prove that the region for which all the magnon densities are non-vanishing is an (m + 1)-simplex in {{{R}}m} whose vertices are the weights of the fundamental representation of \\text{su}(m+1) .
Di Donato, Mariangela; Segado Centellas, Mireia; Lapini, Andrea; Lima, Manuela; Avila, Francisco; Santoro, Fabrizio; Cappelli, Chiara; Righini, Roberto
2014-08-14
The excited state dynamics of carbonyl carotenoids is very complex because of the coupling of single- and doubly excited states and the possible involvement of intramolecular charge-transfer (ICT) states. In this contribution we employ ultrafast infrared spectroscopy and theoretical computations to investigate the relaxation dynamics of trans-8'-apo-β-carotenal occurring on the picosecond time scale, after excitation in the S2 state. In a (slightly) polar solvent like chloroform, one-dimensional (T1D-IR) and two-dimensional (T2D-IR) transient infrared spectroscopy reveal spectral components with characteristic frequencies and lifetimes that are not observed in nonpolar solvents (cyclohexane). Combining experimental evidence with an analysis of CASPT2//CASSCF ground and excited state minima and energy profiles, complemented with TDDFT calculations in gas phase and in solvent, we propose a photochemical decay mechanism for this system where only the bright single-excited 1Bu(+) and the dark double-excited 2Ag(-) states are involved. Specifically, the initially populated 1Bu(+) relaxes toward 2Ag(-) in 200 fs. In a nonpolar solvent 2Ag(-) decays to the ground state (GS) in 25 ps. In polar solvents, distortions along twisting modes of the chain promote a repopulation of the 1Bu(+) state which then quickly relaxes to the GS (18 ps in chloroform). The 1Bu(+) state has a high electric dipole and is the main contributor to the charge-transfer state involved in the dynamics in polar solvents. The 2Ag(-) → 1Bu(+) population transfer is evidenced by a cross peak on the T2D-IR map revealing that the motions along the same stretching of the conjugated chain on the 2Ag(-) and 1Bu(+) states are coupled.
The ground state of medium-heavy nuclei with non central forces
Fabrocini, A
1997-01-01
We study microscopically the ground state properties of 16O and 40Ca nuclei within correlated basis function theory. A truncated version of the realistic Urbana v14 (U14) potential, without momentum dependent terms, is adopted with state dependent correlations having spin, isospin and tensor components. Fermi hypernetted chain integral equations and single operator chain approximation are used to evaluate one- and two-body densities and ground state energy. The results are in good agreement with the available variational MonteCarlo data, providing a first substantial check for the accuracy of the cluster expansion method with state dependent correlations. The finite nuclei treatment of non central interactions and correlations has, at least, the same level of accuracy as in infinite nuclear matter. The binding energy for the full U14+TNI interaction is computed, addressing its small momentum dependent contributions in local density approximation. The nuclei are underbound by about 1 MeV per nucleon. Further e...
Laser cooling a neutral atom to the three-dimensional vibrational ground state of an optical tweezer
Kaufman, Adam M; Regal, Cindy A
2012-01-01
We report three-dimensional ground state cooling of a single neutral atom in an optical tweezer. After employing Raman sideband cooling for 33 ms, we measure via sideband spectroscopy a three-dimensional ground state occupation of ~90%. Ground state neutral atoms in optical tweezers will be instrumental in numerous quantum logic applications and for nanophotonic interfaces that require a versatile platform for storing, moving, and manipulating ultracold single neutral atoms.
Decay rates of large-l Rydberg states of multiply charged ions approaching solid surfaces
Nedeljkovic, N. N.; Mirkovic, M. A.; Bozanic, D. K.
2008-07-01
We investigate the ionization of large-l multiply charged Rydberg ions approaching solid surfaces within the framework of decay model and applying the etalon equation method. The radial coordinate rho of the active electron is treated as a variational parameter and therefore the parabolic symmetry is preserved in this procedure. The complex eigenenergies are calculated from which the energy terms and the ionization rates are derived. We find that the large-l Rydberg states decay at approximately the same ion-surface distances as the low-l states oriented toward the vacuum and considerably closer to the surface comparing to the low-l states oriented towards the surface.
The s-channel charged Higgs in the fully hadronic final state at LHC
Ahmed, Ijaz [University of Malaya, National Center for Particle Physics, Kuala Lumpur (Malaysia); COMSATS Institute of Information Technology (CIIT), Islamabad (Pakistan); Hashemi, Majid [Shiraz University, Physics Department and Biruni Observatory, College of Sciences, Shiraz (Iran, Islamic Republic of); Tajuddin, Wan Ahmad [University of Malaya, National Center for Particle Physics, Kuala Lumpur (Malaysia)
2016-04-15
With the current measurements performed by CMS and ATLAS experiments, the light charged Higgs scenario (m{sub H}{sup {sub ±}} < 160 GeV), is excluded for most of the parameter space in the context of MSSM. However, there is still possibility to look for heavy charged Higgs boson particularly in the s-channel single top production process where the charged Higgs may appear as a heavy resonance state and decay to t anti b. The production process under consideration in this paper is pp → H{sup ±} → t anti b + h.c., where the top quark decays to W{sup +}b and W{sup +} boson subsequently decays to two light jets. It is shown that despite the presence of large QCD and electroweak background events, the charged Higgs signal can be extracted and observed at a large area of MSSM parameter space (m{sub H}{sup {sub ±}}, tanβ) at LHC. The observability of charged Higgs is potentially demonstrated with 5σ contours and 95% confidence level exclusion curves at different integrated LHC luminosities assuming a nominal center of mass energy of √(s) = 14 TeV. (orig.)
Pressure-dependent optical investigations of Fabre salts in the charge-ordered state
Voloshenko, Ievgen; Herter, Melina; Beyer, Rebeca; Pustogow, Andrej; Dressel, Martin
2017-03-01
In a comprehensive infrared study, the molecular vibrational features of (TMTTF)2SbF6, (TMTTF)2AsF6 and (TMTTF)2PF6 single crystals have been measured down to temperatures as low as 7 K by applying hydrostatic pressure up to 11 kbar. We follow the charge disproportionation below the critical temperatures T CO as pressure increases, and determine the critical pressure values p CO at which the charge-ordered phase is suppressed. The coexistence of the spin-Peierls phase with charge order is explored at low temperatures, and the competition of these two phases is observed. Based on our measurements we construct a generic phase diagram of the Fabre salts with centrosymmetric anions. The pressure-dependent anion and methyl-group dynamics in these quasi-one-dimensional charge transfer compounds yields information about the interplay of the organic molecules in the stacks and the anions, and how this interaction varies upon the transition to the charge-ordered state.
Magnetostriction-driven ground-state stabilization in 2H perovskites
Porter, D. G.; Senn, M. S.; Khalyavin, D. D.; Cortese, A.; Waterfield-Price, N.; Radaelli, P. G.; Manuel, P.; zur-Loye, H.-C.; Mazzoli, C.; Bombardi, A.
2016-10-01
The magnetic ground state of Sr3A RuO6 , with A =(Li ,Na ) , is studied using neutron diffraction, resonant x-ray scattering, and laboratory characterization measurements of high-quality crystals. Combining these results allows us to observe the onset of long-range magnetic order and distinguish the symmetrically allowed magnetic models, identifying in-plane antiferromagnetic moments and a small ferromagnetic component along the c axis. While the existence of magnetic domains masks the particular in-plane direction of the moments, it has been possible to elucidate the ground state using symmetry considerations. We find that due to the lack of local anisotropy, antisymmetric exchange interactions control the magnetic order, first through structural distortions that couple to in-plane antiferromagnetic moments and second through a high-order magnetoelastic coupling that lifts the degeneracy of the in-plane moments. The symmetry considerations used to rationalize the magnetic ground state are very general and will apply to many systems in this family, such as Ca3A RuO6 , with A =(Li ,Na ) , and Ca3LiOsO6 whose magnetic ground states are still not completely understood.
On the ground state energy of the delta-function Fermi gas
Tracy, Craig A.; Widom, Harold
2016-10-01
The weak coupling asymptotics to order γ of the ground state energy of the delta-function Fermi gas, derived heuristically in the literature, is here made rigorous. Further asymptotics are in principle computable. The analysis applies to the Gaudin integral equation, a method previously used by one of the authors for the asymptotics of large Toeplitz matrices.
Patterns of the ground states in the presence of random interactions : Nucleon systems
Zhao, YM; Arima, A; Shimizu, N; Ogawa, K; Yoshinaga, N; Scholten, O
2004-01-01
We present our results on properties of ground states for nucleonic systems in the presence of random two-body interactions. In particular, we calculate probability distributions for parity, seniority, spectroscopic (i.e., in the laboratory frame) quadrupole moments, and discuss a clustering in the
Ground states for a modified capillary surface equation in weighted Orlicz-Sobolev space
Guoqing Zhang
2015-03-01
Full Text Available In this article, we prove a compact embedding theorem for the weighted Orlicz-Sobolev space of radially symmetric functions. Using the embedding theorem and critical points theory, we prove the existence of multiple radial solutions and radial ground states for the following modified capillary surface equation $$\\displaylines{ -\\operatorname{div}\\Big(\\frac{|\
Surface Gap Soliton Ground States for the Nonlinear Schr\\"{o}dinger Equation
Dohnal, Tomáš; Reichel, Wolfgang
2010-01-01
We consider the nonlinear Schr\\"{o}dinger equation $(-\\Delta +V(x))u = \\Gamma(x) |u|^{p-1}u$, $x\\in \\R^n$ with $V(x) = V_1(x) \\chi_{\\{x_1>0\\}}(x)+V_2(x) \\chi_{\\{x_10\\}}(x)+\\Gamma_2(x) \\chi_{\\{x_1<0\\}}(x)$ and with $V_1, V_2, \\Gamma_1, \\Gamma_2$ periodic in each coordinate direction. This problem describes the interface of two periodic media, e.g. photonic crystals. We study the existence of ground state $H^1$ solutions (surface gap soliton ground states) for $0<\\min \\sigma(-\\Delta +V)$. Using a concentration compactness argument, we provide an abstract criterion for the existence based on ground state energies of each periodic problem (with $V\\equiv V_1, \\Gamma\\equiv \\Gamma_1$ and $V\\equiv V_2, \\Gamma\\equiv \\Gamma_2$) as well as a more practical criterion based on ground states themselves. Examples of interfaces satisfying these criteria are provided. In 1D it is shown that, surprisingly, the criteria can be reduced to conditions on the linear Bloch waves of the operators $-\\tfrac{d^2}{dx^2} +V_1(x)$ an...
Johnsen, Kristinn; Yngvason, Jakob
1996-01-01
and the electron number N tend to infinity with N/Z fixed, and the magnetic field B tends to infinity in such a way that B/Z4/3→∞. We have calculated electronic density profiles and ground-state energies for values of the parameters that prevail on neutron star surfaces and compared them with results obtained...
Effect of spin-orbit coupling on the ground state structure of mercury
Mishra, Vinayak; Gyanchandani, Jyoti; Chaturvedi, Shashank; Sikka, S. K.
2014-05-01
Near zero kelvin ground state structure of mercury is the body centered tetragonal (BCT) structure (β Hg). However, in all previously reported density functional theory (DFT) calculations, either the rhombohedral or the HCP structure has been found to be the ground state structure. Based on the previous calculations it was predicted that the correct treatment of the SO effects would improve the result. We have performed FPLAPW calculations, with and without inclusion of the SO coupling, for determining the ground state structure. These calculations determine rhombohedral structure as the ground state structure instead of BCT structure. The calculations, without inclusion of SO effect, predict that the energies of rhombohedral and BCT structures are very close to each other but the energy of rhombohedral structure is lower than that of BCT structure at ambient as well as high pressure. On the contrary, the SO calculations predict that though at ambient conditions the rhombohedral structure is the stable structure but on applying a pressure of 3.2 GPa, the BCT structure becomes stable. Hence, instead of predicting the stability of BCT structure at zero pressure, the SO calculations predict its stability at 3.2 GPa. This small disagreement is expected when the energy differences between the structures are small.
Complete $\\alpha^6\\,m$ corrections to the ground state of H$_2$
Puchalski, Mariusz; Czachorowski, Pawel; Pachucki, Krzysztof
2016-01-01
We perform the calculation of all relativistic and quantum electrodynamic corrections of the order of $\\alpha^6\\,m$ to the ground electronic state of a hydrogen molecule and present improved results for the dissociation and the fundamental transitions energies. These results open the window for the high-precision spectroscopy of H$_2$ and related low-energy tests of fundamental interactions.
A New Method for the Atomic Ground-State Energy in the Screened Coulomb Potential
YU Peng-Peng; GUO Hua
2001-01-01
The new method proposed recently by Friedberg,Lee and Zhao is applied to the derivation of the atomic ground-state energy with the inclusion of the screening effect.The present results are compared with those obtained in the pure Coulomb potential and by the variational approach.The overall good results are obtained with this new method.``
Ground-state and Pairing Properties of Pr Isotopes in RMF Theory
2002-01-01
The ground-state and pairing properties of Pr (Z=59) isotopes have been investigated in therelativistic mean-field (RMF). The pairing correlation is studied in Bardeen-Cooper-Schrieffer (BCS) approximation and the pairingforces are taken to be isospin dependent. The ’blocking’ method is adopted to deal with unpaired odd
A Simple Volcano Potential with an Analytic, Zero-Energy, Ground State
Nieto, Michael Martin
2000-01-01
We describe a simple volcano potential, which is supersymmetric and has an analytic, zero-energy, ground state. (The KK modes are also analytic.) It is an interior harmonic oscillator potential properly matched to an exterior angular momentum-like tail. Special cases are given to elucidate the physics, which may be intuitively useful in studies of higher-dimensional gravity.
The ground state energy of the mean field spin glass model
Koukiou, Flora
2008-01-01
From the study of a functional equation of Gibbs measures we calculate the limiting free energy of the Sherrington-Kirkpatrick spin glass model at a particular value of (low) temperature. This implies the following lower bound for the ground state energy $\\epsilon_0$ \\[\\epsilon_0\\geq -0.7833...,\\] close to the replica symmetry breaking and numerical simulations values.
Soluble and stable heptazethrenebis(dicarboximide) with a singlet open-shell ground state
Sun, Zhe
2011-08-10
A soluble and stable heptazethrene derivative was synthesized and characterized for the first time. This molecule exhibits a singlet biradical character in the ground state, which is the first case among zethrene homologue series. Exceptional stability of this heptazethrenebis(dicarboximide) raises the likelihood of its practical applications in materials science. © 2011 American Chemical Society.
Ab initio organic chemistry : a survey of ground- and excited states and aromaticity
Havenith, R.W.A.
2001-01-01
This thesis describes the application of quantum mechanical methods on organic chemistry. The ground- and excited states of functionalized oligo(cyclohexylidenes) have been explored as in function of chain length, conformation and substitution. VB theory has been used to study the effect of cyc
Transient state of polarization in optical ground wire caused by lightning and impulse current
Kurono, Masahiro; Isawa, K.; Kuribara, Masayuki
1996-08-01
This paper describes a transient state of polarization in an optical ground wire (OPGW) theoretically, experimentally and with field measurements in lightning conditions, which is considered one of the fastest phenomena of polarization fluctuations in the natural environment. These characteristics will be required for optical coherent communication for utilities in future and for application to sensing of lightning with OPGW.
Positive and ground state solutions for the critical Klein-Gordon-Maxwell system with potentials
Carriao, Paulo C; Miyagaki, Olimpio H
2010-01-01
In this paper we study a class of Klein-Gordon-Maxwell system when the nonlinearity exhibits critical growth. First we prove both existence and ground state solutions for this system with a periodic potencial V, and then we show the existence in the case that a nonperiodic potencial V is introduced.
Jbara, O; Belhaj, M; Cazaux, J; Rau, E I; Filippov, M; Andrianov, M V
2002-01-01
An original method is proposed to investigate the dynamical trapping properties of bulk insulators during their irradiation by keV electrons when they are coated with a grounded metallic film. This method is based on the measurement of the displacement current and it allows to evaluate time constants for charging and discharging the dielectric as well as to evaluate the electric field build up and trapped charge density below the coating. This method is illustrated by the estimate of the charging and discharging time constants in e sup - irradiated PMMA and the estimate of the magnitude of the electric field which drives the migration of the mobile ions in e sup - irradiated glasses.
Das, Soumyajit
2014-07-23
Polycyclic hydrocarbon compounds with a singlet biradical ground state show unique physical properties and promising material applications; therefore, it is important to understand the fundamental structure/biradical character/physical properties relationships. In this study, para-quinodimethane (p-QDM)-bridged quinoidal perylene dimers 4 and 5 with different fusion modes and their corresponding aromatic counterparts, the pericondensed quaterrylenes 6 and 7, were synthesized. Their ground-state electronic structures and physical properties were studied by using various experiments assisted with DFT calculations. The proaromatic p-QDM-bridged perylene monoimide dimer 4 has a singlet biradical ground state with a small singlet/triplet energy gap (-2.97 kcalmol-1), whereas the antiaromatic s-indacene-bridged N-annulated perylene dimer 5 exists as a closed-shell quinoid with an obvious intramolecular charge-transfer character. Both of these dimers showed shorter singlet excited-state lifetimes, larger two-photon-absorption cross sections, and smaller energy gaps than the corresponding aromatic quaterrylene derivatives 6 and 7, respectively. Our studies revealed how the fusion mode and aromaticity affect the ground state and, consequently, the photophysical properties and electronic properties of a series of extended polycyclic hydrocarbon compounds. A matter of fusion mode! Fusion of a para-quinodimethane (p-QDM) subunit at the peri and β positions of perylene dimers leads to systems with different ground states, that is, open and closed shell (see picture). These systems showed large two-photon absorption cross sections and ultrafast excited-state dynamics relative to their corresponding pericondensed aromatic quaterrylene counterparts. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
The magnetic structure on the ground state of the equilateral triangular spin tube
Matsui, Kazuki; Goto, Takayuki; Manaka, Hirotaka; Miura, Yoko
2016-12-01
The ground state of the frustrated equilateral triangular spin tube CsCrF4 is still hidden behind a veil though NMR spectrum broaden into 2 T at low temperature. In order to investigate the spin structure in an ordered state by 19F-NMR, we have determined the anisotropic hyperfine coupling tensors for each three fluorine sites in the paramagnetic state. The measurement field was raised up to 10 T to achieve highest resolution. The preliminary analysis using the obtained hyperfine tensors has shown that the archetypal 120°-type structure in ab-plane does not accord with the NMR spectra of ordered state.
Ground-State Entanglement and Mixture in an XXZ Spin Chain
WANG Cheng-Zhi; LI Chun-Xian; GUO Guang-Can
2005-01-01
@@ We study the pairwise entanglement and mixture of a three-qubit XXZ spin chain in the ground state in thepresence of an external magnetic field B. The effects of the magnetic field, the anisotropy and the temperature on the entanglement and mixture are considered, and entanglement versus the mixture of all the two-spin states is investigated. We find that the maximal entangled mixed state can be obtained in the considered system by controlling the magnetic field. Our results provide another way to generate maximally entangled mixed states.