Detection of positron-atom bound states through resonant annihilation
Dzuba, V A; Gribakin, G F
2010-01-01
A method is proposed for detecting positron-atom bound states by observing Feshbach resonances in positron annihilation at electron volt energies. The method is applicable to a range of open-shell transition metal atoms which are likely to bind the positron: Si, Fe, Co, Ni, Ge, Tc, Ru, Rh, Sn, Sb, Ta, W, Os, Ir, and Pt.
Formation of positron-atom bound states in collisions between Rydberg Ps and neutral atoms
Swann, A R; Deller, A; Gribakin, G F
2016-01-01
Predicted twenty years ago, positron binding to neutral atoms has not yet been observed experimentally. A new scheme is proposed to detect positron-atom bound states by colliding Rydberg positronium (Ps) with neutral atoms. Estimates of the charge-transfer-reaction cross section are obtained using the first Born approximation for a selection of neutral atom targets and a wide range of incident Ps energies and principal quantum numbers. We also estimate the corresponding Ps ionization cross section. The accuracy of the calculations is tested by comparison with earlier predictions for Ps charge transfer in collisions with hydrogen and antihydrogen. We describe an existing Rydberg Ps beam suitable for producing positron-atom bound states and estimate signal rates based on the calculated cross sections and realistic experimental parameters. We conclude that the proposed methodology is capable of producing such states and of testing theoretical predictions of their binding energies.
International Nuclear Information System (INIS)
The standard method of pionic atom formation does not produce deeply bound pionic atoms. A study is made on the properties of deeply bound pionic atom states by using the standard pion-nucleus optical potential. Another study is made to estimate the cross sections of the formation of ls pionic atom states by various methods. The pion-nucleus optical potential is determined by weakly bound pionic atom states and pion nucleus scattering. Although this potential may not be valid for deeply bound pionic atoms, it should provide some hint on binding energies and level widths of deeply bound states. The width of the ls state comes out to be 0.3 MeV and is well separated from the rest. The charge dependence of the ls state is investigated. The binding energies and the widths increase linearly with Z azbove a Z of 30. The report then discusses various methods to populate deeply bound pionic atoms. In particular, 'pion exchange' reactions are proposed. (n, pπ) reaction is discussed first. The cross section is calculated by assuming the in- and out-going nucleons on-shell and the produced pion in (n1) pionic atom states. Then, (n, dπ-) cross sections are estimated. (p, 2Heπ-) reaction would have cross sections similar to the cross section of (n, dπ-) reaction. In conclusion, it seems best to do (n, p) experiment on heavy nuclei for deeply bound pionic atom. (Nogami, K.)
Calculations of deeply bound pionic states in heavy and superheavy atoms
International Nuclear Information System (INIS)
Binding energies and widths of pions bound in the 1s-state of heavy and superheavy atoms are evaluated. The repulsive strong interaction lowers the Coulomb binding energy by up to 50%. The energy width of the strongest bound state investigated becomes comparable with the binding energy. No drastic consequence on the pion propagation in nuclear matter is expected. (orig.)
International Nuclear Information System (INIS)
The relevance of Quantum Electrodynamics (Qed) in contemporary atomic structure theory is reviewed. Recent experimental advances allow both the production of heavy ions of high charge as well as the measurement of atomic properties with a precision never achieved before. The description of heavy atoms with few electrons via the successive incorporation of one, two, etcetera photons in a rigorous manner and within the bound state Furry representation of Qed is technically feasible. For many-electron atoms the many-body (correlation) effects are very important and it is practically impossible to evaluate all the relevant Feynman diagrams to the required accuracy. Thus, it is necessary to develop a theoretical scheme in which the radiative and nonradiative effects are taken into account in an effective way making emphasis in electronic correlation. Preserving gauge invariance, and avoiding both continuum dissolution and variational collapse are basic problems that must be solved when using effective potential methods and finite-basis representations of them. In this context, we shall discuss advances and problems in the description of atoms as Qed bound states. (Author)
On accurate computations of bound state properties in three- and four-electron atomic systems
Frolov, Alexei M
2016-01-01
Results of accurate computations of bound states in three- and four-electron atomic systems are discussed. Bound state properties of the four-electron lithium ion Li$^{-}$ in its ground $2^{2}S-$state are determined from the results of accurate, variational computations. We also consider a closely related problem of accurate numerical evaluation of the half-life of the beryllium-7 isotope. This problem is of paramount importance for modern radiochemistry.
Bound electron states in clusters of inert atoms in magnetic field
International Nuclear Information System (INIS)
Electron states in inert gas clusters placed into the magnetic field are considered. It is shown that the external magnetic field leads to two important consequences: first, is leads to electron level deepening and consequently, to stabilization of charged cluster; second, the magnetic field leads to much lower values of atom critical numbers, under which the production of electron and cluster bound state is possible. 6 refs., 1 tab
Experimental study of bound and autoionizing Rydberg states of the europium atom
Xiao, Ying; Dai, Chang-Jian; Qin, Wen-Jie
2010-06-01
An isolated-core-excitation (ICE) scheme and stepwise excitation are employed to study the highly excited states of the europium atom. The bound europium spectrum with odd parity in a region of 42400-43500 cm-1 is measured, from which spectral information on 38 transitions, such as level position and relative intensity, can be deduced. Combined with information about excitation calibration and the error estimation process, the selection rules enable us to determine the possible values of total angular momentum J for the observed states. The autoionization spectra of atomic europium, belonging to the 4f76pnl (l = 0, 2) configurations, are systematically investigated by using the three-step laser resonance ionization spectroscopy (RIS) approach. With the ICE scheme, all the experimental spectra of the autoionizing states have nearly symmetric profiles whose peak positions and widths can be easily obtained. A comparison between our results and those from the relevant literature shows that our work not only confirms many reported states, but also discovers 14 bound states and 16 autoionizing states.
Catching the bound states in the continuum of a phantom atom in graphene
Guessi, L. H.; Machado, R. S.; Marques, Y.; Ricco, L. S.; Kristinsson, K.; Yoshida, M.; Shelykh, I. A.; de Souza, M.; Seridonio, A. C.
2015-07-01
We explore theoretically the formation of bound states in the continuum (BICs) in graphene hosting two collinear adatoms situated at different sides of the sheet and at the center of the hexagonal cell, where a phantom atom of a fictitious lattice emulates the six carbons of the cell. We verify that in this configuration the local density of states near the Dirac points exhibits two characteristic features: (i) a cubic dependence on energy instead of a linear one for graphene as found in New J. Phys. 16, 013045 (2014), 10.1088/1367-2630/16/1/013045, and (ii) the formation of BICs as an aftermath of a Fano destructive interference assisted by the Coulomb correlations in the adatoms. For the geometry where adatoms are collinear to carbon atoms, we report an absence of BICs.
Ground state and excitations of a Bose-Einstein condensate of atoms and their diatomic bound states
International Nuclear Information System (INIS)
We study theoretically a many-body system of spinless atoms and their diatomic bound states (or molecules) which form a single Bose-Einstein condensate at zero temperature. The equilibrium states of such a system and its dynamics are analyzed within the Gross-Pitaevskii approach. It is shown that the system exhibits two phases depending on binding energy value: it can be in the states with atomic-molecular condensate or molecular condensate. The basic thermodynamic characteristics of the two phases and their stability conditions are obtained. Both phases are characterized by two branches of collective excitations. The first branch is acoustic mode and the second one is gapfull
Three-body bound states in atomic mixtures with resonant p-wave interaction
Efremov, Maxim A; Ivanov, Misha Yu; Schleich, Wolfgang P
2013-01-01
We employ the Born-Oppenheimer approximation to find the effective potential in a three-body system consisting of a light particle and two heavy ones when the heavy-light short-range interaction potential has a resonance corresponding to a non-zero orbital angular momentum. In the case of an exact resonance in the p-wave scattering amplitude, the effective potential is attractive and long-range, namely it decreases as the third power of the inter-atomic distance. Moreover, we show that the range and power of the potential, as well as the number of bound states are determined by the mass ratio of the particles and the parameters of the heavy-light short-range potential.
Toward the Application of Three-Dimensional Approach to Few-body Atomic Bound States
Hadizadeh, M R
2010-01-01
The first step toward the application of an effective non partial wave (PW) numerical approach to few-body atomic bound states has been taken. The two-body transition amplitude which appears in the kernel of three-dimensional Faddeev-Yakubovsky integral equations is calculated as function of two-body Jacobi momentum vectors, i.e. as a function of the magnitude of initial and final momentum vectors and the angle between them. For numerical calculation the realistic interatomic interactions HFDHE2, HFD-B, LM2M2 and TTY are used. The angular and momentum dependence of the fully off-shell transition amplitude is studied at negative energies. It has been numerically shown that, similar to the nuclear case, the transition amplitude exhibits a characteristic angular behavior in the vicinity of 4He dimer pole.
Toward the Application of Three-Dimensional Approach to Few-body Atomic Bound States
Directory of Open Access Journals (Sweden)
Hadizadeh M.R.
2010-04-01
Full Text Available The ﬁrst step toward the application of an eﬀective non partial wave (PW numerical approach to few-body atomic bound states has been taken. The two-body transition amplitude which appears in the kernel of three-dimensional Faddeev-Yakubovsky integral equations is calculated as function of two-body Jacobi momentum vectors, i.e. as a function of the magnitude of initial and ﬁnal momentum vectors and the angle between them. For numerical calculation the realistic interatomic interactions HFDHE2, HFD-B, LM2M2 and TTY are used. The angular and momentum dependence of the fully oﬀ-shell transition amplitude is studied at negative energies. It has been numerically shown that, similar to the nuclear case, the transition amplitude exhibits a characteristic angular behavior in the vicinity of 4He dimer pole.
Threshold for formation of atom-photon bound states in a coherent photonic band-gap reservoir
Wu, Yunan; Wang, Jing; Zhang, Hanzhuang
2016-05-01
We study the threshold for the formation of atom-photon bound (APB) states from a two-level atom embedded in a coherent photonic band-gap (PBG) reservoir. It is shown that the embedded position of the atom plays an important role in the threshold. By varying the atomic embedded position, a part of formation range of APB states can be moved from inside to outside the band gap. The direct link between the steady-state entanglement and APB states is also investigated. We show that the values of entanglement between reservoir modes reflect the amount of bounded energy caused by APB states. The feasible experimental systems for verifying the above phenomena are discussed. Our results provide a clear clue on how to form and control APB states in PBG materials.
Inversion symmetry breaking of atomic bound states in strong and short laser fields
Stooß, Veit; Ott, Christian; Blättermann, Alexander; Ding, Thomas; Pfeifer, Thomas
2015-01-01
In any atomic species, the spherically symmetric potential originating from the charged nucleus results in fundamental symmetry properties governing the structure of atomic states and transition rules between them. If atoms are exposed to external electric fields, these properties are modified giving rise to energy shifts such as the AC Stark-effect in varying fields and, contrary to this in a constant (DC) electric field for high enough field strengths, the breaking of the atomic symmetry which causes fundamental changes in the atom's properties. This has already been observed for atomic Rydberg states with high principal quantum numbers. Here, we report on the observation of symmetry breaking effects in Helium atoms for states with principal quantum number n=2 utilizing strong visible laser fields. These findings were enabled by temporally resolving the dynamics better than the sub-optical cycle of the applied laser field, utilizing the method of attosecond transient absorption spectroscopy (ATAS). We ident...
Widmann, E; Curceanu, C; Trento 2006; Trento06
2006-01-01
These are the miniproceedings of the workshop "Exotic hadronic atoms, deeply bound kaonic nuclear states and antihydrogen: present results, future challenges," which was held at the European Centre for Theoretical Nuclear Physics and Related Studies (ECT*), Trento (Italy), June 19-24, 2006. The document includes a short presentation of the topics, the list of participants, and a short contribution from each speaker.
Skinner, Brian; Shklovskii, B. I.; Voloshin, M. B.
2013-01-01
Application of a perpendicular electric field induces a band gap in bilayer graphene, and it also creates a "Mexican hat" structure in the dispersion relation. This structure has unusual implications for the hydrogen-like bound state of an electron to a Coulomb impurity. We calculate the ground state energy of this hydrogen-like state as a function of the applied interlayer voltage and the effective fine structure constant. Unlike in the normal hydrogen atom, the resulting wavefunction has ma...
First clear evidence of quantum chaos in the bound states of an atomic nucleus
Muñoz, L; Gómez, J M G; Heusler, A
2016-01-01
We study the spectral fluctuations of the $^{208}$Pb nucleus using the complete experimental spectrum of 151 states up to excitation energies of $6.20$ MeV recently identified at the Maier-Leibnitz-Laboratorium at Garching, Germany. For natural parity states the results are very close to the predictions of Random Matrix Theory (RMT) for the nearest-neighbor spacing distribution. A quantitative estimate of the agreement is given by the Brody parameter $\\omega$, which takes the value $\\omega=0$ for regular systems and $\\omega \\simeq 1$ for chaotic systems. We obtain $\\omega=0.85 \\pm 0.02$ which is, to our knowledge, the closest value to chaos ever observed in experimental bound states of nuclei. By contrast, the results for unnatural parity states are far from RMT behavior. We interpret these results as a consequence of the strength of the residual interaction in $^{208}$Pb, which, according to experimental data, is much stronger for natural than for unnatural parity states. In addition our results show that ch...
Bound entangled states invariant under Ux
Institute of Scientific and Technical Information of China (English)
Wang Zhen; Wang Zhi-Xi
2008-01-01
This paper obtains an entangled condition for isotropic-like states by using an atomic map. It constructs a class of bound entangled states from the entangled condition and shows that the partial transposition of the state from the constructed bound entangled class is an edge bound entangled state by using range criterion.
International Nuclear Information System (INIS)
We discuss the structure and formation of deeply bound π- states in heavy nuclei, which are expected to be narrow due to the repulsive π--nucleus interaction. Possible experiments to produce those states are described. (author)
Bound States of Guided Matter Waves: An Atom and a Charged Wire
Hau, Lene Vestergaard; Burns, Michael M.; Golovchenko, Jene A.
1992-01-01
We argue that it is possible to bind a neutral atom in stable orbits around a wire charged by a time-varying sinusoidal voltage. Both classical and quantum-mechanical theories for this system are discussed, and a unified approach to the Kapitza picture of effective potentials associated with high-frequency fields is presented. It appears that cavities and waveguides for neutral-atomic-matter waves may be fashioned from these considerations.
Hoyer, Paul
2016-01-01
Even a first approximation of bound states requires contributions of all powers in the coupling. This means that the concept of "lowest order bound state" needs to be defined. In these lectures I discuss the "Born" (no loop, lowest order in $\\hbar$) approximation. Born level states are bound by gauge fields which satisfy the classical field equations. As a check of the method, Positronium states of any momentum are determined as eigenstates of the QED Hamiltonian, quantized at equal time. Analogously, states bound by a strong external field $A^\\mu(\\xv)$ are found as eigenstates of the Dirac Hamiltonian. Their Fock states have dynamically created $e^+e^-$ pairs, whose distribution is determined by the Dirac wave function. The linear potential of $D=1+1$ dimensions confines electrons but repels positrons. As a result, the mass spectrum is continuous and the wave functions have features of both bound states and plane waves. The classical solutions of Gauss' law are explored for hadrons in QCD. A non-vanishing bo...
International Nuclear Information System (INIS)
The results of calculating the evolution of the quasi-bound states of the hydrogen atom, moving in the carbon film, are presented. The integral equation, determining the wave functions of the atom pure states, interacting with the surrounding medium, is solved. The estimates of the probability of the hydrogen atom survival by passing through the carbon film in dependence on the film thickness are obtained. The evolution of the quasibound state of the hydrogen molecular ion in the carbon film is considered and the probability of its survival by passing through the carbon film is estimated
Reflecting Magnon Bound States
Ahn, C; Rey, S J
2008-01-01
In N=4 super Yang-Mills spin chain, we compute reflection amplitudes of magnon bound-state off giant graviton. We first compute the reflection amplitude off Y=0 brane boundary and compare it with the scattering amplitude between two magnon bound-states in the bulk. We find that analytic structure of the two amplitudes are intimately related each other: the boundary reflection amplitude is a square-root of the bulk scattering amplitude. Using such relation as a guide and taking known results at weak and strong coupling limits as inputs, we find the reflection amplitude of an elementary magnon off Z=0 giant graviton boundary. The reflection phase factor is shown to solve crossing and unitarity relations. We then compute the reflection amplitude of magnon bound-state off the Z=0 brane boundary and observe that its analytic structures are again intimately related to the bulk scattering and the Y=0 boundary reflection amplitudes. We also take dyonic giant magnon limit of these reflection amplitudes and confirm tha...
Bound states and the Bekenstein bound
Bousso, R
2004-01-01
We explore the validity of the generalized Bekenstein bound, S <= pi M a. We define the entropy S as the logarithm of the number of states which have energy eigenvalue below M and are localized to a flat space region of width a. If boundary conditions that localize field modes are imposed by fiat, then the bound encounters well-known difficulties with negative Casimir energy and large species number, as well as novel problems arising only in the generalized form. In realistic systems, however, finite-size effects contribute additional energy. We study two different models for estimating such contributions. Our analysis suggests that the bound is both valid and nontrivial if interactions are properly included, so that the entropy S counts the bound states of interacting fields.
Coulomb bound states of strongly interacting photons
Maghrebi, M F; Bienias, P; Choi, S; Martin, I; Firstenberg, O; Lukin, M D; Büchler, H P; Gorshkov, A V
2015-01-01
We show that two photons coupled to Rydberg states via electromagnetically induced transparency can interact via an effective Coulomb potential. This interaction gives rise to a continuum of two-body bound states. Within the continuum, metastable bound states are distinguished in analogy with quasi-bound states tunneling through a potential barrier. We find multiple branches of metastable bound states whose energy spectrum is governed by the Coulomb potential, thus obtaining a photonic analogue of the hydrogen atom. Under certain conditions, the wavefunction resembles that of a diatomic molecule in which the two polaritons are separated by a finite "bond length." These states propagate with a negative group velocity in the medium, allowing for a simple preparation and detection scheme, before they slowly decay to pairs of bound Rydberg atoms.
DEFF Research Database (Denmark)
Faupin, Jeremy; Møller, Jacob Schach; Skibsted, Erik
2011-01-01
We study regularity of bound states pertaining to embedded eigenvalues of a self-adjoint operator H, with respect to an auxiliary operator A that is conjugate to H in the sense of Mourre. We work within the framework of singular Mourre theory which enables us to deal with confined massless Pauli......–Fierz models, our primary example, and many-body AC-Stark Hamiltonians. In the simpler context of regular Mourre theory, our results boil down to an improvement of results obtained recently in [8, 9]....
Villalba, Victor M.
1994-01-01
In the present article we analyze the bound states of an electron in a Coulomb field when an Aharonov-Bohm field as well as a magnetic Dirac monopole are present. We solve, via separation of variables, the Schr\\"odinger equation in spherical coordinates and we show how the Hydrogen energy spectrum depends on the Aharonov-Bohm and the magnetic monopole strengths. In passing, the Klein-Gordon equation is solved.
Coulomb Bound States of Strongly Interacting Photons
Maghrebi, M. F.; Gullans, M. J.; Bienias, P.; Choi, S.; Martin, I.; Firstenberg, O.; Lukin, M. D.; Büchler, H. P.; Gorshkov, A. V.
2015-09-01
We show that two photons coupled to Rydberg states via electromagnetically induced transparency can interact via an effective Coulomb potential. This interaction gives rise to a continuum of two-body bound states. Within the continuum, metastable bound states are distinguished in analogy with quasibound states tunneling through a potential barrier. We find multiple branches of metastable bound states whose energy spectrum is governed by the Coulomb potential, thus obtaining a photonic analogue of the hydrogen atom. Under certain conditions, the wave function resembles that of a diatomic molecule in which the two polaritons are separated by a finite "bond length." These states propagate with a negative group velocity in the medium, allowing for a simple preparation and detection scheme, before they slowly decay to pairs of bound Rydberg atoms.
Antibaryon-nucleus bound states
Hrtánková, J
2014-01-01
We calculated antibaryon ($\\bar{B}$ = $\\bar{p}$, $\\bar{\\Lambda}$, $\\bar{\\Sigma}$, $\\bar{\\Xi}$) bound states in selected nuclei within the relativistic mean-field (RMF) model. The G-parity motivated $\\bar{B}$-meson coupling constants were scaled to yield corresponding potentials consistent with available experimental data. Large polarization of the nuclear core caused by $\\bar{B}$ was confirmed. The $\\bar{p}$ annihilation in the nuclear medium was incorporated by including a phenomenological imaginary part of the optical potential. The calculations using a complex $\\bar{p}$-nucleus potential were performed fully self-consistently. The $\\bar{p}$ widths significantly decrease when the phase space reduction is considered for $\\bar{p}$ annihilation products, but they still remain sizeable for potentials consistent with $\\bar{p}$-atom data.
Schulz, M D; Vidal, J
2016-01-01
We discuss the emergence of bound states in the low-energy spectrum of the string-net Hamiltonian in the presence of a string tension. In the ladder geometry, we show that a single bound state arises either for a finite tension or in the zero-tension limit depending on the theory considered. In the latter case, we perturbatively compute the binding energy as a function of the total quantum dimension. We also address this issue in the honeycomb lattice where the number of bound states in the topological phase depends on the total quantum dimension. Finally, the internal structure of these bound states is analyzed in the zero-tension limit.
Bound anionic states of adenine
Harańczyk, Maciej; Gutowski, Maciej; Li, Xiang; Bowen, Kit H.
2007-01-01
Anionic states of nucleic acid bases are involved in DNA damage by low-energy electrons and in charge transfer through DNA. Previous gas phase studies of free, unsolvated nucleic acid base parent anions probed only dipole-bound states, which are not present in condensed phase environments, but did not observe valence anionic states, which for purine bases are thought to be adiabatically unbound. Contrary to this expectation, we have demonstrated that some thus far ignored tautomers of adenine...
Introduction to QCD - a bound state perspective
Hoyer, Paul
2011-01-01
These lecture notes focus on the bound state sector of QCD. Motivated by data which suggests that the strong coupling \\alpha_s(Q) freezes at low Q, and by similarities between the spectra of hadrons and atoms, I discuss if and how QCD bound states may be treated perturbatively. I recall the basic principles of perturbative gauge theory bound states at lowest order in the \\hbar expansion. Born level amplitudes are insensitive to the i\\epsilon prescription of propagators, which allows to eliminate the Z-diagrams of relativistic, time-ordered Coulomb interactions. The Dirac wave function thus describes a single electron which propagates forward in time only, even though the bound state has any number of pair constituents when Feynman propagators are used. In the absence of an external potential, states that are bound by the Coulomb attraction of their constituents can be analogously described using only their valence degrees of freedom. The instantaneous A^0 field is determined by Gauss' law for each wave functi...
Feller, David
2016-01-01
Benchmark quality adiabatic electron affinities for a collection of atoms and small molecules were obtained with the Feller-Peterson-Dixon composite coupled cluster theory method. Prior applications of this method demonstrated its ability to accurately predict atomization energies/heats of formation for more than 170 molecules. In the current work, the 1-particle expansion involved very large correlation consistent basis sets, ranging up to aug-cc-pV9Z (aug-cc-pV10Z for H and H2), with the goal of minimizing the residual basis set truncation error that must otherwise be approximated with extrapolation formulas. The n-particle expansion begins with coupled cluster calculations through iterative single and double excitations plus a quasiperturbative treatment of "connected" triple excitations (CCSD(T)) pushed to the complete basis set limit followed by CCSDT, CCSDTQ, or CCSDTQ5 corrections. Due to the small size of the systems examined here, it was possible in many cases to extend the n-particle expansion to the full configuration interaction wave function limit. Additional, smaller corrections associated with core/valence correlation, scalar relativity, anharmonic zero point vibrational energies, and non-adiabatic effects were also included. The overall root mean square (RMS) deviation was 0.005 eV (0.12 kcal/mol). This level of agreement was comparable to what was found with molecular heats of formation. A 95% confidence level corresponds to roughly twice the RMS value or 0.01 eV. While the atomic electron affinities are known experimentally to high accuracy, the molecular values are less certain. This contributes to the difficulty of gauging the accuracy of the theoretical results. A limited number of electron affinities were determined with the explicitly correlated CCSD(T)-F12b method. After extending the VnZ-F12 orbital basis sets with additional diffuse functions, the F12b method was found to accurately reproduce the best F/F(-) value obtained with standard
Feller, David
2016-01-01
Benchmark quality adiabatic electron affinities for a collection of atoms and small molecules were obtained with the Feller-Peterson-Dixon composite coupled cluster theory method. Prior applications of this method demonstrated its ability to accurately predict atomization energies/heats of formation for more than 170 molecules. In the current work, the 1-particle expansion involved very large correlation consistent basis sets, ranging up to aug-cc-pV9Z (aug-cc-pV10Z for H and H2), with the goal of minimizing the residual basis set truncation error that must otherwise be approximated with extrapolation formulas. The n-particle expansion begins with coupled cluster calculations through iterative single and double excitations plus a quasiperturbative treatment of "connected" triple excitations (CCSD(T)) pushed to the complete basis set limit followed by CCSDT, CCSDTQ, or CCSDTQ5 corrections. Due to the small size of the systems examined here, it was possible in many cases to extend the n-particle expansion to the full configuration interaction wave function limit. Additional, smaller corrections associated with core/valence correlation, scalar relativity, anharmonic zero point vibrational energies, and non-adiabatic effects were also included. The overall root mean square (RMS) deviation was 0.005 eV (0.12 kcal/mol). This level of agreement was comparable to what was found with molecular heats of formation. A 95% confidence level corresponds to roughly twice the RMS value or 0.01 eV. While the atomic electron affinities are known experimentally to high accuracy, the molecular values are less certain. This contributes to the difficulty of gauging the accuracy of the theoretical results. A limited number of electron affinities were determined with the explicitly correlated CCSD(T)-F12b method. After extending the VnZ-F12 orbital basis sets with additional diffuse functions, the F12b method was found to accurately reproduce the best F/F- value obtained with standard
Bound states of 'dressed' particles
International Nuclear Information System (INIS)
A new approach to the problem of bound states in relativistic quantum field theories is suggested. It uses the creation - destruction operators of 'dresses' particles which have been granted by Faddeev's (1963) 'dressing' formalism. Peculiarities of the proposed approach as compared to the known ones are discussed. 8 refs. (author)
Microscopic observation of magnon bound states and their dynamics
Fukuhara, Takeshi; Schauß, Peter; Endres, Manuel; Hild, Sebastian; Cheneau, Marc; Bloch, Immanuel; Gross, Christian
2013-01-01
More than eighty years ago, H. Bethe pointed out the existence of bound states of elementary spin waves in one-dimensional quantum magnets. To date, identifying signatures of such magnon bound states has remained a subject of intense theoretical research while their detection has proved challenging for experiments. Ultracold atoms offer an ideal setting to reveal such bound states by tracking the spin dynamics after a local quantum quench with single-spin and single-site resolution. Here we r...
Precision Study of Positronium: Testing Bound State QED Theory
Karshenboim, Savely G.
2003-01-01
As an unstable light pure leptonic system, positronium is a very specific probe atom to test bound state QED. In contrast to ordinary QED for free leptons, the bound state QED theory is not so well understood and bound state approaches deserve highly accurate tests. We present a brief overview of precision studies of positronium paying special attention to uncertainties of theory as well as comparison of theory and experiment. We also consider in detail advantages and disadvantages of positro...
In-medium antikaon interactions and bound states
Gal, Avraham; Barnea, Nir; Cieplý, Aleš; Mareš, Jiří; Gazda, Daniel
2014-01-01
Correct treatment of subthreshold Kbar-N dynamics is mandatory in kaonic-atom and Kbar-nuclear bound-state calculations, as demonstrated by using in-medium chirally-based models of Kbar-N interactions. Recent studies of kaonic-atom data reveal appreciable multi-nucleon contributions. Kbar-nuclear widths larger than 50 MeV are anticipated.
Instanton bound states in ABJM theory
Energy Technology Data Exchange (ETDEWEB)
Hatsuda, Yasuyuki [DESY Hamburg (Germany). Theory Group; Tokyo Institute of Technology (Japan). Dept. of Physics; Moriyama, Sanefumi [Nagoya Univ. (Japan). Kobayashi Maskawa Inst. and Graduate School of Mathematics; Okuyama, Kazumi [Shinshu Univ., Matsumoto, Nagano (Japan). Dept. of Physics
2013-06-15
The partition function of the ABJM theory receives non-perturbative corrections due to instanton effects. We study these non-perturbative corrections, including bound states of worldsheet instantons and membrane instantons, in the Fermi-gas approach. We require that the total non-perturbative correction should be always finite for arbitrary Chern-Simons level. This finiteness is realized quite non-trivially because each bound state contribution naively diverges at some levels. The poles of each contribution should be canceled out in total. We use this pole cancellation mechanism to find unknown bound state corrections from known ones. We conjecture a general expression of the bound state contribution. Summing up all the bound state contributions, we find that the effect of bound states is simply incorporated into the worldsheet instanton correction by a redefinition of the chemical potential in the Fermi-gas system. Analytic expressions of the 3- and 4-membrane instanton corrections are also proposed.
Bound States of Double Flavor Hyperons
Froemel, F; Riska, D O
2005-01-01
Several realistic phenomenological nucleon-nucleon interaction models are employed to investigate the possibility of bound deuteron-like states of such heavy flavor hyperons and nucleons, for which the interaction between the light flavor quark components is expected to be the most significant interaction. The results indicate that deuteron-like bound states are likely to form between nucleons and the $\\Xi_c^{'}$ and $\\Xi_{cc}$ charm hyperons as well as between $\\Xi$ hyperons and double-charm hyperons. Bound states between two $\\Sigma_c$ hyperons are also likely. In the case of beauty hyperons the corresponding states are likely to be deeply bound.
Bound states of heavy flavor hyperons
Frömel, F.; Juliá-Díaz, B.; Riska, D. O.
2005-04-01
Several realistic phenomenological nucleon-nucleon interaction models are employed to investigate the possibility of bound deuteron-like states of such heavy flavor hyperons and nucleons, for which the interaction between the light flavor quark components is expected to be the most significant interaction. The results indicate that deuteron-like bound states are likely to form between nucleons and the Ξc' and Ξ charm hyperons as well as between Ξ hyperons and double-charm hyperons. Bound states between two Σ hyperons are also likely. In the case of beauty hyperons the corresponding states are likely to be deeply bound.
Bound States at Threshold resulting from Coulomb Repulsion
Gridnev, Dmitry K
2011-01-01
The eigenvalue absorption for a many-particle Hamiltonian depending on a parameter is analyzed in the framework of non-relativistic quantum mechanics. The long-range part of pair potentials is assumed to be pure Coulomb and no restriction on the particle statistics is imposed. It is proved that if the lowest dissociation threshold corresponds to the decay into two likewise non-zero charged clusters then the bound state, which approaches the threshold, does not spread and eventually becomes the bound state at threshold. The obtained results have applications in atomic and nuclear physics. In particular, we prove that atomic ion with atomic critical charge $Z_{cr}$ and $N_e$ electrons has a bound state at threshold given that $Z_{cr} \\in (N_e -2, N_e -1)$, whereby the electrons are treated as fermions and the mass of the nucleus is finite.
Quasi-bound states in continuum
International Nuclear Information System (INIS)
We report the prediction of quasi-bound states (resonant states with very long lifetimes) that occur in the eigenvalue continuum of propagating states for a wide region of parameter space. These quasi-bound states are generated in a quantum wire with two channels and an adatom, when the energy bands of the two channels overlap. A would-be bound state that lays just below the upper energy band is slightly destabilized by the lower energy band and thereby becomes a resonant state with a very long lifetime (a second QBIC lays above the lower energy band). (author)
Bound states of singlet quarks at LHC
Krasnikov, N. V.
1996-01-01
We discuss the discovery potential of the bound states of singlet quarks at LHC. We find that it is possible to discover bound states of singlet quarks at LHC with singlet quark masses up to 300 Gev for $e_{Q} = \\frac{2}{3}$ and up to 200 Gev for $e_{Q} = -\\frac{1}{3}$.
Probing bound states of D-branes
Lifschytz, G
1996-01-01
A zero-brane is used to probe non-threshold BPS bound states of ($p$, $p+2$,$p+4$)-branes. At long distances the stringy calculation agrees with the supergravity calculations. The supergravity description is given, using the interpretation of the $D=8$ dyonic membrane as the bound state of a two-brane inside a four-brane. We investigate the short distance structure of these bound states, compute the phase shift of the scattered zero-brane and find the bound states characteristic size. It is found that there should be a supersymmetric solution of type IIa supergravity, describing a bound state of a zero-brane and two orthogonal two-brane, all inside a four-brane , with an additional unbound zero-brane. We comment on the relationship between $p$-branes and $(p-2)$-branes.
On the reflection of magnon bound states
MacKay, Niall
2010-01-01
We investigate the reflection of two-particle bound states of a free open string in the light-cone AdS_5 x S^5 string sigma model, for large angular momentum J=J_56 and ending on a D7 brane which wraps the entire AdS_5 and a maximal S^3 of S^5. We use the superspace formalism to analyse fundamental and two-particle bound states in the cases of supersymmetry-preserving and broken-supersymmetry boundaries. We find the boundary S-matrices corresponding to bound states both in the bulk and on the boundary.
K-nuclear bound states in a dynamical model
Czech Academy of Sciences Publication Activity Database
Mareš, Jiří; Friedman, E.; Gal, A.
2006-01-01
Roč. 770, 1/2 (2006), s. 84-105. ISSN 0375-9474 Institutional research plan: CEZ:AV0Z10480505 Keywords : kaonic atoms * K-nuclear bound states * K-nucleus interaction Subject RIV: BE - Theoretical Physics Impact factor: 2.155, year: 2006
Black Hole Bound State Metamorphosis
Chowdhury, Abhishek; Saha, Arunabha; Sen, Ashoke
2012-01-01
N=4 supersymmetric string theories contain negative discriminant states whose numbers are known precisely from microscopic counting formulae. On the macroscopic side, these results can be reproduced by regarding these states as multi-centered black hole configurations provided we make certain identification of apparently distinct multi-centered black hole configurations according to a precise set of rules. In this paper we provide a physical explanation of such identifications, thereby establishing that multi-centered black hole configurations reproduce correctly the microscopic results for the number of negative discriminant states without any ad hoc assumption.
Frye, Matthew D; Vaillant, Christophe L; Green, Dermot G; Hutson, Jeremy M
2015-01-01
We calculate near-threshold bound states for the highly anisotropic systems Li+CaH and Li+CaF and perform statistical analysis on the resulting level positions to compare with the predictions of random matrix theory. For Li+CaH with total angular momentum $J=0$ we find fully chaotic behavior in both the nearest-neighbor spacing distribution and the level number variance. However, for $J>0$ we find different behavior due to the presence of a nearly conserved quantum number. Li+CaF ($J=0$) also shows apparently reduced levels of chaotic behavior despite its stronger effective coupling. We suggest this may indicate the development of another good quantum number relating to a bending motion of the complex. However, continuously varying the rotational constant over a wide range shows unexpected structure in the degree of chaotic behavior, including a dramatic reduction around the rotational constant of CaF. This demonstrates the complexity of the relationship between coupling and chaotic behaviour.
'Dressing' and bound states in quantum field theory
International Nuclear Information System (INIS)
The program of introducing 'dressed' particles (instead of 'bare' ones) was suggested earlier by L. Faddev et al. It is modified here for the case when 'dressed' states can decay. On the basis of this 'dressing' formalism, a new approach is proposed to the problem of bound states in field theories such as the hydrogen atom and the positronium in QED or hadrons in QCD. Peculiarities of this approach as compared to the known ones are discussed. 22 refs
Bound - states for truncated Coulomb potentials
Odeh, Maen; Mustafa, Omar
2000-01-01
The pseudoperturbative shifted - $l$ expansion technique PSLET is generalized for states with arbitrary number of nodal zeros. Bound- states energy eigenvalues for two truncated coulombic potentials are calculated using PSLET. In contrast with shifted large-N expansion technique, PSLET results compare excellently with those from direct numerical integration.
Relativistic bound state approach to fundamental forces including gravitation
Directory of Open Access Journals (Sweden)
Morsch H.P.
2012-06-01
Full Text Available To describe the structure of particle bound states of nature, a relativistic bound state formalism is presented, which requires a Lagrangian including scalar coupling of two boson fields. The underlying mechanisms are quite complex and require an interplay of overlapping boson fields and fermion-antifermion production. This gives rise to two potentials, a boson-exchange potential and one identified with the long sought confinement potential in hadrons. With minimal requirements, two elementary massless fermions (quantons - with and without charge - and one gauge boson, hadrons and leptons but also atoms and gravitational systems are described by bound states with electric and magnetic coupling between the charges and spins of quantons. No need is found for colour, Higgs-coupling and supersymmetry.
Sethi, S K; Sethi, Savdeep; Stern, Mark
1998-01-01
We study the existence of D-brane bound states at threshold in Type II string theories. In a number of situations, we can reduce the question of existence to quadrature, and the study of a particular limit of the propagator for the system of D-branes. This involves a derivation of an index theorem for a family of non-Fredholm operators. In support of the conjectured relation between compactified eleven-dimensional supergravity and Type IIA string theory, we show that a bound state exists for two coincident zero-branes. This result also provides support for the conjectured description of M-theory as a matrix model. In addition, we provide further evidence that there are no BPS bound states for two and three-branes twice wrapped on Calabi-Yau vanishing cycles.
Torons and D-Brane Bound States
Guralnik, Z.; Ramgoolam, S.
1997-01-01
We interpret instantons on a torus with twisted boundary conditions, in terms of bound states of branes. The interplay between the SU(N) and U(1) parts of the U(N) theory of N 4-branes allows the construction of a variety of bound states. The SU(N) and U(1) parts can contribute fractional amounts to the total instanton number which is integral. The geometry of non-self intersecting two-cycles in $T^4$ sheds some light on a number of properties of these solutions.
Spin and relativistic motion of bound states
JÃ€rvinen, Matti
2007-01-01
The wave functions of moving bound states may be expected to contract in the direction of motion, in analogy to a rigid rod in classical special relativity, when the constituents are at equal (ordinary) time. Indeed, the Lorentz contraction of wave functions is often appealed to in qualitative discussions. However, only few field theory studies exist of equal-time wave functions in motion. In this thesis I use the Bethe-Salpeter formalism to study the wave function of a weakly bound state suc...
Do $\\Xi\\Xi$ bound states exist?
Haidenbauer, J; Petschauer, S
2014-01-01
The existence of baryon-baryon bound states in the strangeness sector is examined in the framework of SU(3) chiral effective field theory. Specifically, the role of SU(3) symmetry breaking contact terms that arise at next-to-leading order in the employed Weinberg power counting scheme is explored. We focus on the 1S0 partial wave and on baryon-baryon channels with maximal isospin since in this case there are only two independent SU(3) symmetry breaking contact terms. At the same time, those are the channels where most of the bound states have been predicted in the past. Utilizing $pp$ phase shifts and $\\Sigma^+ p$ cross section data allows us to pin down one of the SU(3) symmetry breaking contact terms and a clear indication for the decrease of attraction when going from the NN system to strangeness S=-2 is found, which rules out a bound state for $\\Sigma\\Sigma$ with isospin I=2. Assuming that the trend observed for S=0 to S=-2 is not reversed when going to $\\Xi\\Sigma$ and $\\Xi\\Xi$ makes also bound states in ...
Scattering theory methods for bound state problems
International Nuclear Information System (INIS)
For the analysis of the properties of a bound state system one may use in place of the Schroedinger equation the Lippmann-Schwinger (LS) equation for the wave function or the LS equation for the reactance operator. Use of the LS equation for the reactance operator constrains the solution to have correct asymptotic behaviour, so this approach would appear to be desirable when the bound state wave function is to be used to calculate particle transfer form factors. The Schroedinger equation based N-level analysis of the s-wave bound states of a square well is compared to the ones based on the LS equation. It is found that the LS equation methods work better than the Schroedinger equation method. The method that uses the LS equation for the wave function gives the best results for the wave functions while the method that uses the LS equation for the reactance operator gives the best results for the binding energies. The accuracy of the reactance operator based method is remarkably insensitive to changes in the oscillator constant used for the harmonic oscillator function basis set. It is also remarkably insensitive to the number of nodes in the bound state wave function. (Auth.)
Relativistic bound states at Born level
Hoyer, Paul
2012-01-01
Theoretical and phenomenological studies indicate that the QCD coupling \\alpha_s(Q^2) freezes in the infrared. Hadrons may then be described by a perturbative expansion around "Born" states bound only by a confining potential. A linear potential results from the QCD equations of motion when Gauss' law for A^0 is solved with F_{\\mu\
On the Bound States of Matrix Strings
Sahakian, Vatche
1997-01-01
We investigate excitations in Matrix Theory on T^2 corresponding to bound states of strings. We demonstrate the Dirichlet aspect of R-R charged vacua through a non-trivial connection between the U(1) and SU(n) sectors of the matrix SYM.
Construction of bound entangled states based on permutation operators
Zhao, Hui; Guo, Sha; Jing, Naihuan; Fei, Shaoming
2016-04-01
We present a construction of new bound entangled states from given bound entangled states for arbitrary dimensional bipartite systems. One way to construct bound entangled states is to show that these states are positive partial transpose (PPT) and violate the range criterion at the same time. By applying certain operators to given bound entangled states or to one of the subsystems of the given bound entangled states, we obtain a set of new states which are both PPT and violate the range criterion. We show that the derived bound entangled states are not local unitary equivalent to the original bound entangled states by detail examples.
Deeply bound kaonic states in nuclei
Institute of Scientific and Technical Information of China (English)
LI Yi-He; WU Shi-Shu
2009-01-01
Using a new phenomenological (K)N interaction which reproduces A(1405) as an I = 0 bound state of (K)N, we have investigated K- -3 He(T = 0) and K- -4 He(T = 1/2) within the framework of the Brueckner-Hartree-Fock(BHF) theory. Our calculations show that the above kaonic nuclear systems are both deeply bound. The binding energy BK- is 124.4 MeV(94.1 MeV) and the width Γ is 11.8 MeV(25.8 MeV) for K- -3 He(T = 0)(K- -4 He(T= 1/2)).
Vacuum polarization in hydrogen like relativistic atom: g-factor of bound electrons
International Nuclear Information System (INIS)
The vacuum polarization contribution to the bound electron g-factor of the hydrogen-like atom basic state is considered. The finite expression for the correction is obtained in terms of the summarized hypergeometric functions and it represents the Zα parameters function and orbital particle (electron or muon) relation to the particle mass in the vacuum loop. Various asymptotes of the obtained expression both for ordinary and muon atoms are presented
Mitroy, J.; Bromley, M. W. J.
2006-01-01
The existence of a second bound state of PsH that is electronically stable and also stable against positron annihilation by the normal 2gamma and 3gamma processes is demonstrated by explicit calculation. The state can be found in the 2,4So symmetries with the two electrons in a spin triplet state. The binding energy against dissociation into the H(2p) + Ps(2p) channel was 6.06x10-4 Hartree. The dominant decay mode of the states will be radiative decay into a configuration that autoionizes or ...
Measurement of the magnetic moment of the negative muon bound in different atoms
International Nuclear Information System (INIS)
Theoretical calculations show that the magnetic moment of the electron and the negative muon in the bound state in an atom should be different from the magnetic moment of the free particle due to their relativistic motion. There are also additional radiative corrections to the magnetic moment of a bound electron (muon) due to the presence of the strong Coulomb field of the atomic nucleus. The results of the measurements of the magnetic moment of the negative muon in carbon, oxygen, magnesium, silicon, sulfur, and zinc are presented. The accuracy of the measurements makes it possible to prove the dependence of the relativistic correction to the magnetic moment of a bound muon on Z of the atom
Quarks as quasiparticles of bound states
International Nuclear Information System (INIS)
A treatment of quarks as strongly bound subsystems of the baryon structure is considered, with the baryons assigned to various states with integers G and B. The requirement that the appropriate fractional values of the quantum numbers of the quarks be obtained, and that appropriate integral values be obtained for the whole system of three bound quarks, uniquely determine the three initial states of the quarks, labeled by the set of values of the quantum numbers G, B, and J. In this connection the new color quantum number is interpreted as a quantity which characterizes the presence of the subsystems in different eigenstates. The self- consistency of the changes of color states in the three-quark system is explained on the basis of a generalized Sakata model. (author)
Topological edge states of bound photon pairs
Gorlach, Maxim A
2016-01-01
We predict the existence of interaction-driven edge states of bound two-photon quasiparticles in a dimer periodic array of nonlinear optical cavities. Energy spectrum of photon pairs is dramatically richer than in the noninteracting case or in a simple lattice, featuring collapse and revival of multiple edge and bulk modes as well as edge states in continuum. Despite the unexpected breakdown of the Zak phase technique and the edge mixing of internal and center-of-mass motion we link the edge state existence to the two-photon quantum walk graph connectivity, thus uncovering the topological nature of the many-body problem in complex lattices.
Analytic continuation of bound states to solve resonance states
Energy Technology Data Exchange (ETDEWEB)
Tanaka, Norimichi; Arai, Koji [Niigata Univ. (Japan); Suzuki, Yoshiyuki; Varga, K.
1997-05-01
As a method to determine the parameters of the resonance state, a method is proposed using analytic continuation on bound constants of correlation. The characteristics of this method consists in probability of prediction of the parameters of the resonance state only by calculation of the bound state. Owing to conducting the analytic continuation on square root of energy in the bound state as a function relating to the bound constant, energy and width in the bound state was determined. Here was reported on a result of application of this method to three systems. Some partial wave on two systems showing correlation at a simple potential and a resonance state of zero of all orbital angular motion quality in three boson system were determined using the analytic continuation method. These results agreed well with one used a method of integrating Schroedinger equation directly and one used the complex scaling method, and this method was found to be much efficient for the study of the resonance state. Under a background of becoming applicable to the method of analytic continuation, there was development of calculating method for the recent small number multi system. As the characteristics of the analytic continuation method is used for only calculation of the bound state, it is convenient at a point applicable to the method to obtain conventional bound state and then is much efficient in a point of applicability of calculus of variations. However, in order to obtain coefficient of Pade approximation correctly, the bound state must be solved correctly, which is difficult for more complex system and is not always applicable to every systems. (G.K.)
Tsirelson's bound and supersymmetric entangled states
Borsten, L; Duff, M J
2012-01-01
In order to see whether superqubits are more nonlocal than ordinary qubits, we construct a class of two-superqubit entangled states as a nonlocal resource in the CHSH game. Since super Hilbert space amplitudes are Grassmann numbers, the result depends on how we extract real probabilities and we examine three choices of map: (1) DeWitt (2) Trigonometric (3) Modified Rogers. In cases (1) and (2) the winning probability reaches the Tsirelson bound p(win) = cos^2 pi/8 \\simeq 0.8536 of standard quantum mechanics. Case (3) crosses Tsirelson's bound with p(win) = 0.9265. Although all states used in the game involve probabilities lying between 0 and 1, case (3) permits other changes of basis inducing negative transition probabilities.
Quantum Bound States Around Black Holes
Grain, J.; Barrau, A.
2007-01-01
Quantum mechanics around black holes has shown to be one of the most fascinating fields of theoretical physics. It involves both general relativity and particle physics, opening new eras to establish the principles of unified theories. In this article, we show that quantum bound states with no classical equivalent -- as it can easily be seen at the dominant monopolar order -- should be formed around black holes for massive scalar particles. We qualitatively investigate some important physical...
Closed form bound-state perturbation theory
Directory of Open Access Journals (Sweden)
Ollie J. Rose
1980-01-01
Full Text Available The perturbed Schrödinger eigenvalue problem for bound states is cast into integral form using Green's Functions. A systematic algorithm is developed and applied to the resulting equation giving rise to approximate solutions expressed as functions of the given perturbation parameter. As a by-product, convergence radii for the traditional Rayleigh-Schrödinger and Brillouin-Wigner perturbation theories emerge in a natural way.
Weakly bound states in heterogeneous waveguides
Amore, Paolo; Fernández, Francisco M.; Hofmann, Christoph P.
2016-07-01
We study the spectrum of the Helmholtz equation in a two-dimensional infinite waveguide, containing a weak heterogeneity localized at an internal point, and obeying Dirichlet boundary conditions at its border. We use the variational theorem to derive the condition for which the lowest eigenvalue of the spectrum falls below the continuum threshold and a bound state appears, localized at the heterogeneity. We devise a rigorous perturbation scheme and derive the exact expression for the energy to third order in the heterogeneity.
Semirelativistic Bound-State Equations: Trivial Considerations
Directory of Open Access Journals (Sweden)
Lucha Wolfgang
2014-01-01
Full Text Available Observing renewed interest in long-standing (semi- relativistic descriptions of two-body bound states, we would like to make a few comments on the eigenvalue problem posed by the spinless Salpeter equation and, illustrated by the examples of the nonsingular Woods–Saxon potential and the singular Hulthén potential, recall elementary tools that, in their quest, practitioners looking for analytic albeit approximate solutions will find useful.
Deeply bound pionic atoms: the story of an ongoing race
International Nuclear Information System (INIS)
A short review is made of the steps of the Valencia group in the search for suitable reactions to detect deeply bound pionic states and how these steps were influenced by the parallel steps of the Tokyo team. The present situation and future prospects are outlined. (orig.)
Andreev bound states. Some quasiclassical reflections
International Nuclear Information System (INIS)
We discuss a very simple and essentially exactly solvable model problem which illustrates some nice features of Andreev bound states, namely, the trapping of a single Bogoliubov quasiparticle in a neutral s-wave BCS superfluid by a wide and shallow Zeeman trap. In the quasiclassical limit, the ground state is a doublet with a splitting which is proportional to the exponentially small amplitude for “normal” reflection by the edges of the trap. We comment briefly on a prima facie paradox concerning the continuity equation and conjecture a resolution to it
Andreev bound states. Some quasiclassical reflections
Energy Technology Data Exchange (ETDEWEB)
Lin, Y., E-mail: yiriolin@illinois.edu; Leggett, A. J. [University of Illinois at Urhana-Champaign, Dept. of Physics (United States)
2014-12-15
We discuss a very simple and essentially exactly solvable model problem which illustrates some nice features of Andreev bound states, namely, the trapping of a single Bogoliubov quasiparticle in a neutral s-wave BCS superfluid by a wide and shallow Zeeman trap. In the quasiclassical limit, the ground state is a doublet with a splitting which is proportional to the exponentially small amplitude for “normal” reflection by the edges of the trap. We comment briefly on a prima facie paradox concerning the continuity equation and conjecture a resolution to it.
Bounding quantum gravity inspired decoherence using atom interferometry
Minář, Jiří; Sangouard, Nicolas
2016-01-01
Hypothetical models have been proposed in which explicit collapse mechanisms prevent the superposition principle to hold at large scales. In particular, the model introduced by Ellis and co-workers [Phys. Lett. B ${\\bf 221}$, 113 (1989)] suggests that quantum gravity might be responsible for the collapse of the wavefunction of massive objects in spatial superpositions. We here consider a recent experiment reporting on interferometry with atoms delocalized over half a meter for timescale of a second [Nature ${\\bf 528}$, 530 (2015)] and show that the corresponding data strongly bound quantum gravity induced decoherence and rule it out in the parameter regime considered originally.
Unexpected strong attraction in the presence of continuum bound state
International Nuclear Information System (INIS)
The result of few-particle ground-state calculation employing a two-particle non-local potential supporting a continuum bound state in addition to a negative-energy bound state has occasionally revealed unexpected large attraction in producing a very strongly bound ground state. In the presence of the continuum bound state the difference of phase shift between zero and infinite energies has an extra jump of φ as in the presence of an additional bound state. The wave function of the continuum bound state is identical with that of a strongly bound negative-energy state, which leads us to postulate a pseudo bound state in the two-particle system in order to explain the unexpected attraction. The role of the Pauli forbidden states is expected to be similar to these pseudo states. (author)
Bound states -- from QED to QCD
Hoyer, Paul
2014-01-01
These lectures are divided into two parts. In Part 1 I discuss bound state topics at the level of a basic course in field theory: The derivation of the Schr\\"odinger and Dirac equations from the QED Lagrangian, by summing Feynman diagrams and in a Hamiltonian framework. Less well known topics include the equal-time wave function of Positronium in motion and the properties of the Dirac wave function for a linear potential. The presentation emphasizes physical aspects and provides the framework...
Is there an quasi-bound state?
Wilkin, C; Chiladze, D; Dymov, S; Hanhart, C; Hartmann, M; Hejny, V; Kacharava, A K; Keshelashvili, I; Khoukaz, A; Maeda, Y; Mersmann, T; Mielke, M; Mikirtychiants, S; Papenbrock, M; Rathmann, F; Rausmann, T; Schleichert, R; Ströher, H; Täschner, A; Valdau, Yu; Wronska, A
2007-01-01
The observed variation of the total cross section for the dp -> 3He eta reaction near threshold means that the magnitude of the s--wave amplitude falls very rapidly with the eta centre--of--mass momentum. It is shown here that recent measurements of the momentum dependence of the angular distribution imply a strong variation also in the phase of this amplitude. Such a behaviour is that expected from a quasi--bound or virtual eta-3He state. The interpretation can be investigated further through measurements of the deuteron or proton analysing powers and/or spin--correlations.
A balance for Dark Matter bound states
Nozzoli, F.
2016-01-01
Massive particles with self interactions of the order of 0.2 barn/GeV are intriguing Dark Matter candidates from an astrophysical point of view. Direct detection searches for very massive particles, with relatively high cross sections with ordinary matter, cannot rule out $\\sigma/M > 0.01$ barn/GeV, due to atmosphere and material shielding. Here, the possibility of the existence of bound states with ordinary matter, for Dark Matter candidates with not negligible interactions, is considered. T...
Novel Bound States in Graphene with Impurities
Gupta, Kumar S
2008-01-01
We obtain a novel bound state spectrum of the low energy excitations near the Fermi points of graphene in the presence of a charge impurity. The effects of possible short range interactions induced by the impurity are modelled by suitable boundary conditions. The spectrum in the subcritical region of the effective Coulomb coupling is labelled by a parameter which characterizes the boundary conditions and determines the inequivalent quantizations of the system. In the supercritical region we obtain a renormalization group flow for the effective Coulomb coupling.
On Aharonov-Casher bound states
Energy Technology Data Exchange (ETDEWEB)
Silva, E.O. [Universidade Federal do Maranhao, Departamento de Fisica, Sao Luis, MA (Brazil); Andrade, F.M. [Universidade Estadual de Ponta Grossa, Departamento de Matematica e Estatistica, Ponta Grossa, PR (Brazil); Filgueiras, C. [Universidade Federal de Campina Grande, Departamento de Fisica, Caixa Postal 10071, Campina Grande, PB (Brazil); Belich, H. [Universidade Federal do Espirito Santo, Departamento de Fisica e Quimica, Vitoria, ES (Brazil)
2013-04-15
In this work bound states for the Aharonov-Casher problem are considered. According to Hagen's work on the exact equivalence between spin-1/2 Aharonov-Bohm and Aharonov-Casher effects, is known that the {nabla}.E term cannot be neglected in the Hamiltonian if the spin of particle is considered. This term leads to the existence of a singular potential at the origin. By modeling the problem by boundary conditions at the origin which arises by the self-adjoint extension of the Hamiltonian, we derive for the first time an expression for the bound state energy of the Aharonov-Casher problem. As an application, we consider the Aharonov-Casher plus a two-dimensional harmonic oscillator. We derive the expression for the harmonic oscillator energies and compare it with the expression obtained in the case without singularity. At the end, an approach for determination of the self-adjoint extension parameter is given. In our approach, the parameter is obtained essentially in terms of physics of the problem. (orig.)
Hadron QCD (Bound states in gauge theories)
International Nuclear Information System (INIS)
The general principles of the description of bound states in QED and QCD are proposed for the aim of construction of the consistent scheme of calculating hadron spectrum and interaction amplitudes. Such principles are the explicit solution of the Gauss equation for time component, the quantization of the minimal set physical variables and the choice of the time-axis of quantization in accordance with the Markov-Yukawa relativistic theory of bilocal fields. QCD constructed by these principles contains new infrared divergences, changing the behaviour of the Coulomb field on large distances. This divergences (like ones in QED) are removed out with the help of phenomenology, in this case, by taking into account the rising potential as the 'nonperturbative background' for a new perturbation theory. It is shown how in such hadron theory the parton model, nonrelativistic potential spectroscopy, chiral Lagrangian and confinement appear. The Dirac quantization method, renormalization group equations and lattice calculations in their conventional formulation are proved to be untenable for the description of bound states. 23 refs
ADMonium: Asymmetric Dark Matter Bound State
Bi, Xiao-Jun; Ko, P; Li, Jinmian; Li, Tianjun
2016-01-01
We propose a novel framework for asymmetric scalar dark matter (ADM), which has interesting collider phenomenology in terms of an unstable ADM bound state (ADMonium) produced via Higgs portals. ADMonium is a natural consequence of the basic features of ADM: the (complex scalar) ADM is charged under a dark local $U(1)_d$ symmetry which is broken at a low scale and provides a light gauge boson $X$. The dark gauge coupling is strong and then ADM can annihilate away into $X$-pair effectively. Therefore, the ADM can form bound state due to its large self-interaction via $X$ mediation. To explore the collider signature of ADMonium, we propose that ADM has a two-Higgs doublet portal. The ADMonium can have a sizable mixing with the heavier Higgs boson, which admits a large cross section of ADMonium production associated with $b\\bar b$. Of particular interest, our setup nicely explains the recent di-photon anomaly at 750 GeV via the events from ${\\rm ADMonium}\\ra 2X(\\ra e^+e^-)$, where the electrons are identified as ...
Bound states -- from QED to QCD
Hoyer, Paul
2014-01-01
These lectures are divided into two parts. In Part 1 I discuss bound state topics at the level of a basic course in field theory: The derivation of the Schr\\"odinger and Dirac equations from the QED Lagrangian, by summing Feynman diagrams and in a Hamiltonian framework. Less well known topics include the equal-time wave function of Positronium in motion and the properties of the Dirac wave function for a linear potential. The presentation emphasizes physical aspects and provides the framework for Part 2, which discusses the derivation of relativistic bound states at Born level in QED and QCD. A central aspect is the maintenance of Poincar\\'e invariance. The transformation of the wave function under boosts is studied in detail in D=1+1 dimensions, and its generalization to D=3+1 is indicated. Solving Gauss' law for $A^0$ with a non-vanishing boundary condition leads to a linear potential for QCD mesons, and an analogous confining potential for baryons.
A balance for Dark Matter bound states
Nozzoli, F
2016-01-01
Massive particles with self interactions of the order of 0.2 barn/GeV are intriguing Dark Matter candidates from an astrophysical point of view. Direct detection searches for very massive particles, with relatively high cross sections with ordinary matter, cannot rule out $\\sigma/M > 0.01$ barn/GeV, due to atmosphere and material shielding. Here, the possibility of the existence of bound states with ordinary matter, for Dark Matter candidates with not negligible interactions, is considered. The existence of bound states, with binding energy larger than $\\sim$1 meV, would offer the possibility to test in laboratory capture cross sections of the order of a barn (or larger). The signature of the detection of a mass increasing of cryogenic samples, due to the possible Dark Matter accumulation, would allow the investigation of Dark Matter particles with mass up to the GUT scale. A proof of concept for a possible detection set-up and the evaluation of some noise sources are described.
Exact Entanglement Cost of Multi-Qubit Bound Entangled States
Bandyopadhyay, Somshubhro; Roychowdhury, Vwani P.
2005-01-01
We report the exact entanglement cost of a class of multiqubit bound entangled states, computed in the context of a universal model for multipartite state preparation. The exact amount of entanglement needed to prepare such states are determined by first obtaining lower bounds using a cut-set approach, and then providing explicit local protocols achieving the lower bound.
Collision-produced atomic states
International Nuclear Information System (INIS)
The last 10-15 years have witnessed the development of a new, powerful class of experimental techniques for atomic collision studies, allowing partial or complete determination of the state of the atoms after a collision event, i.e. the full set of quantum-mechanical scattering amplitudes or - more generally - the density matrix describing the system. Evidently, such studies, involving determination of alignment and orientation parameters, provide much more severe tests of state-of-the-art scattering theories than do total or differential cross section measurements which depend on diagonal elements of the density matrix. The off-diagonal elements give us detailed information about the shape and dynamics of the atomic states. Therefore, close studies of collision-produced atomic states are currently leading to deeper insights into the fundamental physical mechanisms governing the dynamics of atomic collision events. The first part of the lectures deals with the language used to describe atomic states, while the second part presents a selection of recent results for model systems which display fundamental aspects of the collision physics in particularly instructive ways. I shall here restrict myself to atom-atom collisions. The discussion will be focused on states decaying by photon emission though most of the ideas can be easily modified to include electron emission as well. (orig./AH)
Excited, bound and resonant positron-atom systems
Energy Technology Data Exchange (ETDEWEB)
Bromley, M W J [Department of Physics and Computational Science Research Center, San Diego State University, San Diego CA 92182 (United States); Mitroy, J, E-mail: mbromley@physics.sdsu.ed [ARC Centre for Antimatter-Matter Studies and Faculty of Education, Health and Science, Charles Darwin University, Darwin NT 0909 (Australia)
2010-01-01
Calculations have demonstrated that eleven neutral atoms can bind positrons, while many more can bind positronium. This is a short review of recent progress made in understanding some of the underlying mechanisms. The emphasis here being on configuration interaction calculations with excited state configurations. These have demonstrated the existence of a {sup 2}P{sup o} excited state of e{sup +}Ca, which consists predominantly of a positronium cluster orbiting the Ca{sup +} ion in the L = 1 partial wave. Preliminary results are presented of excited state positron binding to a model alkali atom, where the excited {sup 1}P{sup o} states are stable over a limited region. Implications for the unnatural parity, {sup 2,4}S{sup o}, states of PsH, LiPs, NaPs and KPs are also discussed. The e{sup +}Mg, e{sup +}Cu, e{sup +}Zn and e{sup +}Cd systems show a lack of a {sup 2}P{sup o} excited state, each instead possessing a low-energy p-wave shape resonance of varying strength.
Excited, bound and resonant positron-atom systems
International Nuclear Information System (INIS)
Calculations have demonstrated that eleven neutral atoms can bind positrons, while many more can bind positronium. This is a short review of recent progress made in understanding some of the underlying mechanisms. The emphasis here being on configuration interaction calculations with excited state configurations. These have demonstrated the existence of a 2Po excited state of e+Ca, which consists predominantly of a positronium cluster orbiting the Ca+ ion in the L = 1 partial wave. Preliminary results are presented of excited state positron binding to a model alkali atom, where the excited 1Po states are stable over a limited region. Implications for the unnatural parity, 2,4So, states of PsH, LiPs, NaPs and KPs are also discussed. The e+Mg, e+Cu, e+Zn and e+Cd systems show a lack of a 2Po excited state, each instead possessing a low-energy p-wave shape resonance of varying strength.
Bound states and Lorentz-Poincare symmetry
International Nuclear Information System (INIS)
A hypothesis of the ''relation-continuum'' C is put forward, closely connected with isolation of physical system, which extends to finite universal constant c the absolute nature of the Galilean relative coordinates and the absolute Newtonian time. Points of C4 continuum are directly unobservable and the relativistic symmetry L4 of directly observable space-time events becomes the limiting case of the C4-symmetry. Consequently, though the possibility of the hypothesis of C4-continuum is due to quantum physics, the modifications it implies come with finite universal constant (h/2π)/c and concern the description of the internal structure of bound states only. The C4-symmetry of relations, as weaker than the Lorentz-Poincare L4-symmetry of events, makes ''more room'' for quantum dynamical models. The Feynman graphs phenomenology with form factors (vertex functions) of non-point particles left for experimental determination can be connected with the C4-framework which determines their analytic structure. The C4-effects then would reveal themselves only in these processes in which composite particles participate. Therefore, the ''good'' quantum electrodynamics of point-particles is left unmodified. Two off-mass-shell effects are analyzed in the relatively low-energy processes which are connected with the mass-dependent localization of the center-of-mass of composite particle ''M''. They seem to be crucial for the hypothesis itself. (author)
Squashed giants: bound states of giant gravitons
International Nuclear Information System (INIS)
We consider giant gravitons in the maximally supersymmetric type IIB plane-wave, in the presence of a constant NSNS B-field background. We show that in response to the background B-field the giant graviton would take the shape of a deformed three-sphere, the size and shape of which depend on the B-field, and that the giant becomes classically unstable once the B-field is larger than a critical value Bcr. In particular, for the B-field which is (anti-)self-dual under the SO(4) isometry of the original giant S3, the closed string metric is that of a round S3, while the open string metric is a squashed three-sphere. The squashed giant can be interpreted as a bound state of a spherical three-brane and circular D-strings. We work out the spectrum of geometric fluctuations of the squashed giant and study its stability. We also comment on the gauge theory which lives on the brane (which is generically a noncommutative theory) and a possible dual gauge theory description of the deformed giant. (author)
Real weights, bound states and duality orbits
Marrani, Alessio; Romano, Luca
2015-01-01
We show that the duality orbits of extremal black holes in supergravity theories with symmetric scalar manifolds can be derived by studying the stabilizing subalgebras of suitable representatives, realized as bound states of specific weight vectors of the corresponding representation of the duality symmetry group. The weight vectors always correspond to weights that are real, where the reality properties are derived from the Tits-Satake diagram that identifies the real form of the Lie algebra of the duality symmetry group. Both N=2 magic Maxwell-Einstein supergravities and the semisimple infinite sequences of N=2 and N=4 theories in D=4 and 5 are considered, and various results, obtained over the years in the literature using different methods, are retrieved. In particular, we show that the stratification of the orbits of these theories occurs because of very specific properties of the representations: in the case of the theory based on the real numbers, whose symmetry group is maximally non-compact and there...
Real weights, bound states and duality orbits
Marrani, Alessio; Riccioni, Fabio; Romano, Luca
2016-01-01
We show that the duality orbits of extremal black holes in supergravity theories with symmetric scalar manifolds can be derived by studying the stabilizing subalgebras of suitable representatives, realized as bound states of specific weight vectors of the corresponding representation of the duality symmetry group. The weight vectors always correspond to weights that are real, where the reality properties are derived from the Tits-Satake diagram that identifies the real form of the Lie algebra of the duality symmetry group. Both 𝒩 = 2 magic Maxwell-Einstein supergravities and the semisimple infinite sequences of 𝒩 = 2 and 𝒩 = 4 theories in D = 4 and 5 are considered, and various results, obtained over the years in the literature using different methods, are retrieved. In particular, we show that the stratification of the orbits of these theories occurs because of very specific properties of the representations: in the case of the theory based on the real numbers, whose symmetry group is maximally noncompact and therefore all the weights are real, the stratification is due to the presence of weights of different lengths, while in the other cases it is due to the presence of complex weights.
Effects of Bound States on Dark Matter Annihilation
An, Haipeng; Wise, Mark B.; Zhang, Yue
2016-01-01
We study the impact of bound state formation on dark matter annihilation rates in models where dark matter interacts via a light mediator, the dark photon. We derive the general cross section for radiative capture into all possible bound states, and point out its non-trivial dependence on the dark matter velocity and the dark photon mass. For indirect detection, our result shows that dark matter annihilation inside bound states can play an important role in enhancing signal rates over the rat...
Effects of Bound States on Dark Matter Annihilation
An, Haipeng; Wise, Mark B.; Zhang, Yue
2016-01-01
We study the impact of bound state formation on dark matter annihilation rates in models where dark matter interacts via a light mediator, the dark photon. We derive the general cross section for radiative capture into all possible bound states, and point out its non-trivial dependence on the dark matter velocity and the dark photon mass. For indirect detection, our result shows that dark matter annihilation inside bound states can play an important role in enhancing signal ...
Bound states and the Lorentz symmetry
International Nuclear Information System (INIS)
Basing on the geometrical hypothesis called the relation continuum C4 two off-mass-shell effects that are crucial for this hypothesis are evaluated. The first effect concerns an anomalous behaviour of the cross-section of inelastic electron-atom collision in keV's energy region, the second accounts for the modification of the momentum distribution of spectator electrons resulting from the disintegration of the atom in electron-atom collision. (author)
Supercurrent in Atomic Point Contacts and Andreev States
Goffman, M. F.; Cron, R.; Levy Yeyati, A.; Joyez, P.; Devoret, M. H.; Esteve, D.; Urbina, C.
2000-07-01
We have measured the supercurrent in aluminum atomic point contacts containing a small number of well characterized conduction channels. For most contacts, the measured supercurrent is adequately described by the opposite contributions of two thermally populated Andreev bound states per conduction channel. However, for contacts containing an almost perfectly transmitted channel 0.9<=τ<=1 the measured supercurrent is higher than expected, a fact that we attribute to nonadiabatic transitions between bound states.
Dark matter and stable bound states of primordial black holes
Chavda, L K; Chavda, Abhijit L.
2002-01-01
We present three reasons for the formation of gravitational bound states of primordial black holes,called holeums,in the early universe.Using Newtonian gravity and nonrelativistic quantum mechanics we find a purely quantum mechanical mass-dependant exclusion property for the nonoverlap of the constituent black holes in a holeum.This ensures that the holeum occupies space just like ordinary matter.A holeum emits only gravitational radiation whose spectrum is an exact analogue of that of a hydrogen atom. A part of this spectrum lies in the region accessible to the detectors being built.The holeums would form haloes around the galaxies and would be an important component of the dark matter in the universe today.They may also be the constituents of the invisible domain walls in the universe.
Dark matter and stable bound states of primordial black holes
International Nuclear Information System (INIS)
We present three reasons for the formation of gravitational bound states of primordial black holes, called holeums, in the early universe. Using Newtonian gravity and nonrelativistic quantum mechanics we find a purely quantum mechanical mass-dependent exclusion property for the nonoverlap of the constituent black holes in a holeum. This ensures that the holeum occupies space just like ordinary matter. A holeum emits only gravitational radiation whose spectrum is an exact analogue of that of a hydrogen atom. A part of this spectrum lies in the region accessible to the detectors being built. The holeums would form haloes around the galaxies and would be an important component of the dark matter in the universe today. They may also be the constituents of the invisible domain walls in the universe
Pure bound field corrections to the atomic energy levels and the proton size puzzle
Kholmetskii, Alexander L; Yarman, Tolga
2013-01-01
Reinforcement of the puzzle about the proton charge radius r, stimulated by the recent experiments with muonic hydrogen induced news discussions on the subject, and now some physicists are ready to adopt the exotic properties of muon, lying beyond the Standard Model, in order to explain the difference between the results of muonic hydrogen experiments (r=0.84087(39) fm) and CODATA-2010 value r=0.8775(51) fm based on electron-proton scattering and H spectroscopy. In the present contribution we suggest a way to achieve a progress in the entire problem via paying attention on a logical inconsistency of fundamental equations of atomic physics, constructed by analogy with corresponding classical equations without, however, taking into account a purely bound nature of electromagnetic field generated by electrically bound particles in the stationary energy states. We suggest eliminating this inconsistency via introducing some appropriate correcting factors into these equations, which involve the requirement of total...
Dark-matter bound states from Feynman diagrams
K. Petraki; M. Postma; M. Wiechers
2015-01-01
If dark matter couples directly to a light force mediator, then it may form bound states in the early universe and in the non-relativistic environment of haloes today. In this work, we establish a field-theoretic framework for the computation of bound-state formation cross-sections, de-excitation an
Bound states in a hyperbolic asymmetric double-well
Energy Technology Data Exchange (ETDEWEB)
Hartmann, R. R., E-mail: richard.hartmann@dlsu.edu.ph [Physics Department, De La Salle University, 2401 Taft Avenue, Manila (Philippines)
2014-01-15
We report a new class of hyperbolic asymmetric double-well whose bound state wavefunctions can be expressed in terms of confluent Heun functions. An analytic procedure is used to obtain the energy eigenvalues and the criterion for the potential to support bound states is discussed.
Tauonium tau+tau-, a bound state of heavy leptons
International Nuclear Information System (INIS)
Some properties of an electromagnetically bound state of the recently discovered tau heavy lepton are analyzed. This bound state of tau+tau-, has been called tauonium, T. It is found that the process e+e-→T→X has a very high cross section but that it might have escaped observation because of the very narrow width of the T
The representation of bound state wavefunctions by spherical Hankel functions
International Nuclear Information System (INIS)
The representation of a nucleon bound state by a single Hankel function is generalised such that the bound state is expanded as a linear combination of Hankel functions of the same l-value. The singularity at the origin due to the use of Hankel functions is removed. The arguments and coefficients of the expansion are determined by a variational method. (orig.)
Asymptotic properties of bound states in coupled quantum wave guides
Energy Technology Data Exchange (ETDEWEB)
Maglione, Enrico [Dipartimento di Fisica G Galilei, Via F Marzolo 8, Padova (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Padova (Italy); Centro de Fisica das Interaccoes Fundamentais (CFIF), Avenida Rovisco Pais, Lisbon (Portugal); Departamento de Fisica, Instituto Superior Tecnico, Avenida Rovisco Pais, P1049-001 Lisbon (Portugal); Ferreira, LIdia S [Centro de Fisica das Interaccoes Fundamentais (CFIF), Avenida Rovisco Pais, Lisbon (Portugal); Departamento de Fisica, Instituto Superior Tecnico, Avenida Rovisco Pais, P1049-001 Lisbon (Portugal); Cattapan, Giorgio [Dipartimento di Fisica G Galilei, Via F Marzolo 8, Padova (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Padova (Italy)
2006-02-03
We investigate the motion of bound-state poles in two quantum wave guides laterally coupled through a window. The imaginary momentum ik at the bound-state poles is studied as a function of the size a of the window. Both bound and virtual states appear as a spans the whole range from 0 up to +{infinity}. We are able to find simple scaling laws relating the critical value of the window size at which the nth bound state appears to the number n of bound states, in the limit of large n. A similar relation is also provided for the slope and the second derivative of the pole trajectories in the (k, a) plane. These relations are characterized by an extremely high numerical accuracy. We also evaluate the exact value of the first two derivatives for a = 0.
Recent advances in bound state quantum electrodynamics
International Nuclear Information System (INIS)
Recent developments are reviewed in four areas of computational quantum electrodynamics: a new relativistic two-body formalism equal in rigor to the Bethe-Salpeter formalism but with strong calculational advantages is discussed; recent work on the computation of the decay rate of bound systems (positronium in particular) is presented; limits on possible composite structure of leptons are discussed; a new multidimensional integration program ('VEGAS') suitable for higher order calculations is presented
Realizing a Kondo-correlated state with ultracold atoms
Bauer, Johannes; Salomon, Christophe; Demler, Eugene
2013-01-01
We propose a novel realization of Kondo physics with ultracold atomic gases. It is based on a Fermi sea of two different hyperfine states of one atom species forming bound states with a different species, which is spatially confined in a trapping potential. We show that different situations displaying Kondo physics can be realized when Feshbach resonances between the species are tuned by a magnetic field and the trapping frequency is varied. We illustrate that a mixture of \\(^{40}K\\) and \\(^{...
Coexistence of bound and virtual-bound states in shallow-core to valence x-ray spectroscopies
Sen Gupta, Subhra; Bradley, J. A.; Haverkort, M. W.; Seidler, G. T.; Tanaka, A.; Sawatzky, G. A.
2011-08-01
With the example of the non-resonant inelastic x-ray scattering (NIXS) at the O45 edges (5d→5f) of the actinides, we develop the theory for shallow-core to valence excitations, where the multiplet spread is larger than the core-hole attraction, such as if the core and valence orbitals have the same principal quantum number. This involves very strong final state configuration interaction (CI), which manifests itself as huge reductions in the Slater-Condon integrals, needed to explain the spectral shapes within a simple renormalized atomic multiplet theory. But more importantly, this results in a cross-over from bound (excitonic) to virtual-bound excited states with increasing energy, within the same core-valance multiplet structure, and in large differences between the dipole and high-order multipole transitions, as observed in NIXS. While the bound states (often higher multipole allowed) can still be modeled using local cluster-like models, the virtual-bound resonances (often dipole-allowed) cannot be interpreted within such local approaches. This is in stark contrast to the more familiar core-valence transitions between different principal quantum number shells, where all the final excited states almost invariably form bound core-hole excitons and can be modeled using local approaches. The possibility of observing giant multipole resonances for systems with high angular momentum ground states is also predicted. The theory is important to obtain ground state information from core-level x-ray spectroscopies of strongly correlated transition metal, rare-earth, and actinide systems.
Weakly bound states of polar molecules in bilayers
Fedorov, D V; Zinner, N T; Jensen, A S
2011-01-01
We investigate a system of two polarized molecules in a layered trap. The molecules reside in adjacent layers and interact purely via the dipole-dipole interaction. We determine the properties of the ground state of the system as a function of the dipole moment and polarization angle. A bound state is always present in the system and in the weak binding limit the bound state extends to a very large distance and shows universal behavior.
Relativistic bound states: a mass formula for vector mesons
International Nuclear Information System (INIS)
In the framework of a relativistic description of two particles bound states, a mass formula for vector mesons considered as quark-antiquark systems bound by harmonic oscillator like forces is proposed. Results in good agreement with experimental values are obtained
Higgs interchange and bound states of superheavy fermions
Indian Academy of Sciences (India)
M De Sanctis
2013-09-01
Hypothetical superheavy fourth-generation fermions with a very small coupling with the rest of the Standard Model can give rise to long enough lived bound states. The production and the detection of these bound states would be experimentally feasible at the LHC. Extending, in the present study, the analysis of other authors, a semirelativistic wave equation is solved using an accurate numerical method to determine the binding energies of these possible superheavy fermion-bound states. The interaction given by the Yukawa potential of the Higgs boson exchange is considered; the corresponding relativistic corrections are calculated by means of a model based on the covariance properties of the Hamiltonian. We study the effects given by the Coulomb force. Moreover, we calculate the contributions given by the Coulombic and confining terms of the strong interaction in the case of superheavy quark bound states. The results of the model are critically analysed.
Transport Through Andreev Bound States in a Graphene Quantum Dot
Dirks, Travis; Hughes, Taylor L.; Lal, Siddhartha; Uchoa, Bruno; Chen, Yung-Fu; Chialvo, Cesar; Goldbart, Paul M.; Mason, Nadya
2010-01-01
Andreev reflection-where an electron in a normal metal backscatters off a superconductor into a hole-forms the basis of low energy transport through superconducting junctions. Andreev reflection in confined regions gives rise to discrete Andreev bound states (ABS), which can carry a supercurrent and have recently been proposed as the basis of qubits [1-3]. Although signatures of Andreev reflection and bound states in conductance have been widely reported [4], it has been difficult to directly...
Unparticle contribution to the hydrogen atom ground state energy
Wondrak, Michael F.; Nicolini, Piero; Bleicher, Marcus
2016-08-01
In the present work we study the effect of unparticle modified static potentials on the energy levels of the hydrogen atom. By using Rayleigh-Schrödinger perturbation theory, we obtain the energy shift of the ground state and compare it with experimental data. Bounds on the unparticle energy scale ΛU as a function of the scaling dimension dU and the coupling constant λ are derived. We show that there exists a parameter region where bounds on ΛU are stringent, signaling that unparticles could be tested in atomic physics experiments.
Atomic Quantum State Teleportation and Swapping
Kuzmich, A.; Polzik, E. S.
2000-01-01
A set of protocols for atomic quantum state teleportation and swapping utilizing Einstein-Podolsky-Rosen light is proposed. The protocols are suitable for collective spin states of a macroscopic sample of atoms, i.e. for continuous atomic variables. Feasibility of experimental realization for teleportation of a gas sample of atoms is analyzed.
Bound States of a Ferromagnetic Wire in a Superconductor
Sau, Jay D.; Brydon, P. M. R.
2015-09-01
We consider the problem of bound states in strongly anisotropic ferromagnetic impurities in a superconductor, motivated by recent experiments that claim to observe Majorana modes at the ends of ferromagnetic wires on a superconducting substrate [S. Nadj-Perge et al., Science 346, 602 (2014)]. Generalizing the successful theory of bound states of spherically symmetric impurities, we consider a wirelike potential using both analytical and numerical approaches. We find that away from the ends of the wire the bound states form bands with pronounced van Hove singularities, giving rise to subgap peaks in the local density of states. For sufficiently strong magnetization of the wire, we show that this process generically produces a sharp peak at zero energy in the local density of states near the ends of the wire. This zero-energy peak has qualitative similarities to the claimed signature of a Majorana mode observed in the aforementioned experiment.
Bound States of a Ferromagnetic Wire in a Superconductor.
Sau, Jay D; Brydon, P M R
2015-09-18
We consider the problem of bound states in strongly anisotropic ferromagnetic impurities in a superconductor, motivated by recent experiments that claim to observe Majorana modes at the ends of ferromagnetic wires on a superconducting substrate [S. Nadj-Perge et al., Science 346, 602 (2014)]. Generalizing the successful theory of bound states of spherically symmetric impurities, we consider a wirelike potential using both analytical and numerical approaches. We find that away from the ends of the wire the bound states form bands with pronounced van Hove singularities, giving rise to subgap peaks in the local density of states. For sufficiently strong magnetization of the wire, we show that this process generically produces a sharp peak at zero energy in the local density of states near the ends of the wire. This zero-energy peak has qualitative similarities to the claimed signature of a Majorana mode observed in the aforementioned experiment. PMID:26431011
Bounding quantum gravity inspired decoherence using atom interferometry
Minář, Jiří; Sekatski, Pavel; Sangouard, Nicolas
2016-01-01
Hypothetical models have been proposed in which explicit collapse mechanisms prevent the superposition principle to hold at large scales. In particular, the model introduced by Ellis and co-workers [Phys. Lett. B ${\\bf 221}$, 113 (1989)] suggests that quantum gravity might be responsible for the collapse of the wavefunction of massive objects in spatial superpositions. We here consider a recent experiment reporting on interferometry with atoms delocalized over half a meter for timescale of a ...
Graphene in inhomogeneous magnetic fields: bound, quasi-bound and scattering states
Energy Technology Data Exchange (ETDEWEB)
Ramezani Masir, M; Peeters, F M [Departement Fysica, Universiteit Antwerpen Groenenborgerlaan 171, B-2020 Antwerpen (Belgium); Vasilopoulos, P, E-mail: mrmphys@gmail.com, E-mail: takis@alcor.concordia.ca, E-mail: francois.peeters@ua.ac.be [Department of Physics, Concordia University, Montreal, Quebec, H4B 1R6 (Canada)
2011-08-10
The electron states in graphene-based magnetic dot and magnetic ring structures and combinations of both are investigated. The corresponding spectra are studied as a function of the radii, the strengths of the inhomogeneous magnetic field and of a uniform background field, the strength of an electrostatic barrier and the angular momentum quantum number. In the absence of an external magnetic field we have only long-lived quasi-bound and scattering states and we assess their influence on the density of states. In addition, we consider elastic electron scattering by a magnetic dot, whose average B vanishes, and show that the Hall and longitudinal resistivities, as a function of the Fermi energy, exhibit a pronounced oscillatory structure due to the presence of quasi-bound states. Depending on the dot parameters this oscillatory structure differs substantially for energies below and above the first Landau level.
Boson bound states in the -Fermi–Pasta–Ulam model
Indian Academy of Sciences (India)
Xin-Guang Hu; Ju Xiang; Zheng Jiao; Yang Liu; Guo-Qiu Xie; Ke Hu
2013-11-01
The bound states of four bosons in the quantum -Fermi–Pasta–Ulam model are investigated and some interesting results are presented using the number conserving approximation combined with the number state method. We find that the relative magnitude of anharmonic coefficient has a significant effect on forming localized energy in the model, and the wave number plays an important role in forming different bound states. The signature of the quantum breather is also set up by the square of the amplitudes of the corresponding eigenvectors in real space.
Effects of Bound States on Dark Matter Annihilation
An, Haipeng; Zhang, Yue
2016-01-01
We study the impact of bound state formation on dark matter annihilation rates in models where dark matter interacts via a light mediator, the dark photon. We derive the general cross section for radiative capture into all possible bound states, and point out its non-trivial dependence on the dark matter velocity and the dark photon mass. For indirect detection, our result shows that dark matter annihilation inside bound states can play an important role in enhancing signal rates over the rate for direct dark matter annihilation with Sommerfeld enhancement. The effects are strongest for large dark gauge coupling and when the dark photon mass is smaller than the typical momentum of dark matter in the galaxy. As an example, we show that for thermal dark matter the Fermi gamma ray constraint is substantially increased once bound state effects are taken into account. We also find that bound state effects are not important for dark matter annihilation during the freeze out and recombination epochs.
Proximity induced interface bound states in superconductor-graphene junctions
Burset, P.; Herrera, W.; Yeyati, A. Levy
2009-01-01
We show that interface bound states are formed at isolated graphene-superconductor junctions. These states arise due to the interplay of virtual Andreev and normal reflections taking place at these interfaces. Simple analytical expressions for their dispersion are obtained considering interfaces formed along armchair or zig-zag edges. It is shown that the states are sensitive to a supercurrent flowing on the superconducting electrode. The states provide long range superconducting correlations...
Probing Majorana Bound States in T-Shaped Junctions
Wu, Bin-He; Cheng, Xiao; Wang, Chun-Rui; Gong, Wei-Jiang
2014-03-01
We investigate the transport properties of a pair of Majorana bound states in a T-shaped junction, where two normal leads are coupled with an identical Majorana bound state. Both the scattering matrix and the recursive Green function method show that the peak value of the differential conductance (Gpeak) in units of e2/h and the shot noise Fano factor in the zero bias limit (F0), which are measured at the same lead and zero temperature, satisfy a linear relation as F0 = 1 + Gpeak/2, independent of the magnitude or symmetry of the coupling strengths to the leads. Therefore, combined measurements of the differential conductance and shot noise in the T-shaped geometry can serve as a characteristic signature in probing Majorana bound states.
A brief review on Majorana bound states in topological superconductors
Lin, Rui; Wang, Zhi
2016-07-01
Topological superconductivity has drawn much attention recently, and most interests are focused on the Majorana bound states existing at the edges of one-dimensional topological superconductors. These Majorana bound states are ideal platform for studying non-Abelian statistics. Meanwhile, they are proposed to be useful in quantum computation. In this review, we introduce the basic concepts and models in this area. We begin from the Kitaev model, which is the most concise model for one-dimensional topological superconductivity. Then, we discuss how to realize this model with spin-orbit coupling in realistic materials. Finally, we show some simple methods to detect the Majorana bound states and study their novel properties with the help of adjacent quantum dots.
International Nuclear Information System (INIS)
Illustrous, eloquent, and yet easy to read for the interested layman, the book begins with alleged deplorable conditions at the reprocessing centra La Hague, portrays, amongst other things, the spying on and supervision of persons in the nuclear field and in research, the misuse of fissile material, and threats and blackmail as a consequence thereof, human error as a cause of accidents, and it concludes with a nonviolent new International against the state and atomic energy, against technological tyranny. Titles of chapters: The hard road; radiation feed; the gamblers; homo atomicus; the intimidated; the ''proliferators''; nuclear terrorists; those supervised; the smooth road. It remains an open question whether the book contributes to defusing the nuclear controversy - in the book almost an ideology - and to bringing the two sides closer together. (HP)
Question of η- and K−- Nucleus Bound States
International Nuclear Information System (INIS)
Interaction of the η-meson and that of the K−-meson with nucleons is of special interest because both of them are strongly attractive near threshold. This raises the strong possibility that we may find in nature the bound η- and K−-nuclear (quasi) bound states. This led to experimental programs to hunt for the existence of these states and theoretical studies to keep pace with them. The efforts had positive results. The η-meson studies had been there for several years by now, while those with the K−-meson had been relatively recent. The talk gives a brief critical overview of the η-nuclear interaction studies, especially in context with the η-mesic state explorations. For the K−-meson we give a brief summary of the efforts in understanding the basic K−-nucleon interaction and theoretical explorations for the existence of K−-nucleus bound states. We critically examine the FINUDA measurements as a signal for the existence of the K−-nucleus bound states, especially in context with the contribution of the single nucleon knock-out final state interaction in the (K−, pΛ) reaction.
An Upper Bound of Fully Entangled Fraction of Mixed States
Huang, Xiao-Fen; Jing, Nai-Huan; Zhang, Ting-Gui
2016-06-01
We study the fully entangled fraction of a quantum state. An upper bound is obtained for arbitrary bipartite system. This upper bound only depends on the Frobenius norm of the state. Supported by the National Natural Science Foundation of China under Grant Nos. 11401032, 11501153, 11271138, and 11531004; the Natural Science Foundation of Hainan Province under Grant Nos. 20151010, 114006 and 20161006; and the Scientific Research Foundation for Colleges of Hainan Province under Grant No. Hnky2015-18 and Simons Foundation under Grant No. 198129
A framework for bounding nonlocality of state discrimination
Childs, Andrew M.; Leung, Debbie; Mancinska, Laura; Ozols, Maris
2012-01-01
We consider the class of protocols that can be implemented by local quantum operations and classical communication (LOCC) between two parties. In particular, we focus on the task of discriminating a known set of quantum states by LOCC. Building on the work in the paper "Quantum nonlocality without entanglement" [BDF+99], we provide a framework for bounding the amount of nonlocality in a given set of bipartite quantum states in terms of a lower bound on the probability of error in any LOCC dis...
Directional detection of dark matter in universal bound states
Energy Technology Data Exchange (ETDEWEB)
Laha, Ranjan
2015-10-01
It has been suggested that several small-scale structure anomalies in CDM cosmology can be solved by strong self-interaction between dark matter particles. It was shown in Ref. [1] that the presence of a near threshold S-wave resonance can make the scattering cross section at nonrelativistic speeds come close to saturating the unitarity bound. This can result in the formation of a stable bound state of two asymmetric dark matter particles (which we call darkonium). Ref. [2] studied the nuclear recoil energy spectrum in dark matter direct detection experiments due to this incident bound state. Here we study the angular recoil spectrum, and show that it is uniquely determined up to normalization by the S-wave scattering length. Observing this angular recoil spectrum in a dark matter directional detection experiment will uniquely determine many of the low-energy properties of dark matter independent of the underlying dark matter microphysics.
On Deusons or Deuteronlike Meson-Meson Bound States
Törnqvist, N A
1994-01-01
The systematics of deuteronlike two-meson bound states, {\\it deusons}, is discussed. Previous arguments that many of the present non-$q\\bar q$ states are such states are elaborated including, in particular, the tensor potential. For pseudoscalar states the important observation is made that the centrifugal barrier from the P-wave can be overcome by the $1/r^2$ and $1/r^3$ terms of the tensor potential. In the heavy meson sector one-pion exchange alone is strong enough to form at least deuteron-like $B\\bar B^*$ and $B^*\\bar B^*$ composites bound by approximately 50 MeV, while $D\\bar D^*$ and $D^*\\bar D^*$ states are expected near the threshold.
Near relativistic study of bound levels in atoms. Application to alkaline atoms
Energy Technology Data Exchange (ETDEWEB)
Varade, A.; Delgado-Barrio, G.; Villarreal, P. (Consejo Superior de Investigaciones Cientificas, Madrid (Spain). Inst. de Estructura de la Materia)
1985-01-01
A model is described for the calculation of the atomic binding energies. The Pauli equation has been solved with a local potential. The results for alkaline atoms are reported here and compared with the perturbative calculation and experimental data.
A search for unexpected bound states in 15B
Hoffman, Calem R.
2014-09-01
Bound states in 15B are to be populated through the one proton removal reaction from a 16C beam produced at the RCNP EN Course through 18O fragmentation. γ-decays from these states will be identified by an array of Compton-suppressed HPGe Clover detectors (CAGRA). The goals consist of i) identifying any previously unobserved and unexpected bound states in 15B and ii) to assign total angular momenta to known excited states for the first time. At present only two bound states have been observed in 15B, neither with firm spin or parity assignments. The present work to be discussed is aimed at determining whether an excited 3 /2- state, a state with identical spin-parity as the ground state, resides below the neutron separation energy in 15B. Such an excited 3 /2- state is not predicted to appear below the 15B Sn by shell-model calculations using various p- sd interactions. However, a robust systematic, probably related to the s-wave trends found in the single-neutron states in this region, has been observed for neutron-rich N=10 nuclei and it suggests that the state may appear lower in excitation energy than expected. Providing some measure of validation for the N=10 prediction is a similar trend noticed in the energy differences between ground (p)2 neutron states and excited (sd)2 neutron states in the N=8 neutron-rich isotones. In addition to a search for this unexpected state, additional spectroscopic information on 15B will better aid in the understanding of the N=10 isotones when transitioning from 16C into sparsely probed 14Be. Details of the experimental procedures and motivation will be presented and discussed. Bound states in 15B are to be populated through the one proton removal reaction from a 16C beam produced at the RCNP EN Course through 18O fragmentation. γ-decays from these states will be identified by an array of Compton-suppressed HPGe Clover detectors (CAGRA). The goals consist of i) identifying any previously unobserved and unexpected bound
Towards flavored bound states beyond rainbows and ladders
El-Bennich, B; Paracha, M A; de Melo, J P B C
2013-01-01
We give a snapshot of recent progress in solving the Dyson-Schwinger equation with a beyond rainbow-ladder ansatz for the dressed quark-gluon vertex which includes ghost contributions. We discuss the motivations for this approach with regard to heavy-flavored bound states and form factors and briefly describe future steps to be taken.
Towards flavored bound states beyond rainbows and ladders
Energy Technology Data Exchange (ETDEWEB)
El-Bennich, B.; Rojas, E.; Melo, J. P. B. C. de [Laboratório de Física Teórica e Computacional, Universidade Cruzeiro do Sul, São Paulo 01506-000 SP (Brazil); Paracha, M. A. [Laboratorio de Fisica Teorica e Computacional, Universidade Cruzeiro do Sul, Sao Paulo 01506-000 SP, Brazil and Centre for Advanced Mathematics and Physics, National University of Science and Technology, Islamabad (Pakistan)
2014-11-11
We give a snapshot of recent progress in solving the Dyson-Schwinger equation with a beyond rainbow-ladder ansatz for the dressed quark-gluon vertex which includes ghost contributions. We discuss the motivations for this approach with regard to heavy-flavored bound states and form factors and briefly describe future steps to be taken.
Bound States and Supercriticality in Graphene-Based Topological Insulators
Directory of Open Access Journals (Sweden)
Reinhold Egger
2013-01-01
Full Text Available We study the bound state spectrum and the conditions for entering a supercritical regime in graphene with strong intrinsic and Rashba spin-orbit interactions within the topological insulator phase. Explicit results are provided for a disk-shaped potential well and for the Coulomb center problem.
Dynamics of deeply bound (K) over-bar states
Czech Academy of Sciences Publication Activity Database
Mareš, Jiří; Friedman, E.; Gal, A.
2007-01-01
Roč. 22, 2-3 (2007), s. 633-636. ISSN 0217-751X R&D Projects: GA AV ČR IAA100480617 Institutional research plan: CEZ:AV0Z10480505 Keywords : over-bar-nuclear bound states * over-bar-nuclear relativistic mean field calculations Subject RIV: BE - Theoretical Physics Impact factor: 0.764, year: 2007
Approximate solution of bound state problems through continued fractions
International Nuclear Information System (INIS)
A method to solve ordinary linear differential equations through continued fractions is applied to several physical systems. In particular, results for the Schroedinger equation give a good accuracy for the eigenvalues of bound states in the S-wave Yukawa potential, and the lowest order approximations provide exact values for the harmonic oscillator and Coulomb potential eigenvalues and eigenfuctions. (orig.)
Effective field theories for non-relativistic bound states
International Nuclear Information System (INIS)
I review some of the progress made in the last ten years in providing a solid foundation to the description of non-relativistic bound states in QED and QCD by means of effective field theories. I will discuss some applications. (author)
Bound states in the continuum in quasiperiodic systems
Energy Technology Data Exchange (ETDEWEB)
Hsueh, W.J., E-mail: hsuehwj@ntu.edu.t [Department of Engineering Science, National Taiwan University, Taipei 10660, Taiwan (China); Chen, C.H.; Chang, C.H. [Department of Engineering Science, National Taiwan University, Taipei 10660, Taiwan (China)
2010-11-01
We first propose the existence of bound states in the continuums (BICs) in quasiperiodic systems. Owing to long-range correlation, destructive interference may occur in quasiperiodic systems with higher generation order. Occurrences of BICs in Fibonacci quantum wells studied by localization analysis and gap map method are proposed.
Polarization control of the bound state of a vector soliton
International Nuclear Information System (INIS)
This article demonstrates that the number of pulses in a group of vector bound solitons can be accurately adjusted by polarization control. We could achieve states with up to seven pulses trapped in a group with equally firm pulse separation. The stable relative phase between pulses within the group is manifested as an interference pattern in the soliton spectrum. (letter)
Bound States in the AdS/CFT Correspondence
Minces, P
2004-01-01
We consider a massive scalar field theory in anti-de Sitter space, in both minimally and non-minimally coupled cases. We introduce a relevant double-trace perturbation at the boundary, by carefully identifying the correct source and generating functional for the corresponding conformal operator. We show that such relevant double-trace perturbation introduces changes in the coefficients in the boundary terms of the action, which in turn govern the existence of a bound state in the bulk. For instance, in the minimally coupled case, we show that the usual action, containing no additional boundary terms, gives rise to a bound state, which can be avoided only through the addition of a proper boundary term. Another notorious example is that of a conformally coupled scalar field, for which there is no associated bound state. In general, in both minimally and non-minimally coupled cases, we explicitly compute the boundary terms which give rise to a bound state, and which ones do not. In the non-minimally coupled case...
Gluon mass generation in the massless bound-state formalism
Ibañez, D
2012-01-01
We present a detailed, all-order study of gluon mass generation within the massless bound-state formalism, which constitutes the general framework for the systematic implementation of the Schwinger mechanism in non-Abelian gauge theories. The main ingredient of this formalism is the dynamical formation of bound-states with vanishing mass, which give rise to effective vertices containing massless poles; these latter vertices, in turn, trigger the Schwinger mechanism, and allow for the gauge-invariant generation of an effective gluon mass. This particular approach has the conceptual advantage of relating the gluon mass directly to quantities that are intrinsic to the bound-state formation itself, such as the "transition amplitude" and the corresponding "bound-state wave-function". As a result, the dynamical evolution of the gluon mass is largely determined by a Bethe-Salpeter equation that controls the dynamics of the relevant wave-function, rather than the Schwinger-Dyson equation of the gluon propagator, as h...
Closed string brane-like states, brane bound states and noncommutative branes
International Nuclear Information System (INIS)
We study the mass and different RR charge distributions of the BPS (p,p-2)-brane bound states in the closed string brane-like σ-model. We show that such brane bound states can be realized by introducing a constant B field in the closed string theory. In addition we show that the worldvolume coordinates of these brane bound states turn out to be noncommutative. (author)
A differential method for bounding the ground state energy
Mouchet, A
2005-01-01
For a wide class of Hamiltonians, a novel method to obtain lower and upper bounds for the lowest energy is presented. Unlike perturbative or variational techniques, this method does not involve the computation of any integral (a normalisation factor or a matrix element). It just requires the determination of the absolute minimum and maximum in the whole configuration space of the local energy associated with a normalisable trial function (the calculation of the norm is not needed). After a general introduction, the method is applied to three non-integrable systems: the asymmetric annular billiard, the many-body spinless Coulombian problem, the hydrogen atom in a constant and uniform magnetic field. Being more sensitive than the variational methods to any local perturbation of the trial function, this method can used to systematically improve the energy bounds with a local skilled analysis; an algorithm relying on this method can therefore be constructed and an explicit example for a one-dimensional problem is...
Effective Hamiltonian for bound states in Yukawa theory
International Nuclear Information System (INIS)
A generalization of the Gell-Mann–Low theorem is applied to lowest nontrivial order to determine an effective Hamiltonian for two-fermion states in relativistic Yukawa theory. The consistency of the corresponding effective Schrödinger equation is thoroughly investigated in various aspects, among others the nonrelativistic and one-body limits, and the small-distance or large-momentum regime of the bound state solutions is discussed in detail. -- Highlights: •A generalization of the Gell-Mann–Low theorem is applied to Yukawa theory. •The effective Hamiltonian for two-fermion states is derived to lowest order. •The nonrelativistic and one-body limits are consistent. •The large-momentum behavior of the bound-state solutions is analyzed. •A critical value for the coupling constant is determined
Observation of bound states in Lieb photonic lattices
Vicencio, Rodrigo A; Morales-Inostroza, Luis; Real, Bastian; Weimann, Steffen; Szameit, Alexander; Molina, Mario I
2014-01-01
We present the first experimental demonstration of a new type of bound states in the continuum, namely, compacton-like linear states in flat bands lattices. To this end, photonic Lieb lattices are employed, which exhibit three tight-binding bands, with one being perfectly flat. Our results could be of great importance for fundamental physics as well as for various applications concerning imaging and data transmission.
Dynamics Resonances in Atomic States of Astrophysical Relevance
Indian Academy of Sciences (India)
K. N. Arefieff; K. Miculis; N. N. Bezuglov; M. S. Dimitrijević; A. N. Klyucharev; A. A. Mihajlov; V. A. Srećković
2015-12-01
Ionized geocosmic media parameters in a thermal and a subthermal range of energy have a number of unique features. The photoresonance plasma that is formed by optical excitation of the lowest excited (resonance) atomic states is one example of conversion of radiation energy into electrical one. Since spontaneous fluorescence of excited atoms is probabilistic, the description of the radiating quantized system evolution along with photon energy transfer in a cold atom medium, should include elements of stochastic dynamics. Finally, the chaotic dynamics of a weakly bound Rydberg electron over a grid of the energy level diagram of a quasi-molecular Rydberg complex provides an excitation migration of the electron forward to the ionization continuum. This work aims at discussing the specific features of the dynamic resonances formalism in the description of processes involving Rydberg states of an excited atom, including features in the fluorescence spectrum partially caused by the quantum defect control due to the presence of statistic electromagnetic fields.
Dynamics Resonances in Atomic States of Astrophysical Relevance
Arefieff, K N; Bezuglov, N N; Dimitrijevic, M S; Klyucharev, A N; Mihajlov, A A; Sreckovic, V A
2016-01-01
Ionized geocosmic media parameters in a thermal and a subthermal range of energy have a number of unique features. The photoresonance plasma that is formed by optical excitation of the lowest excited (resonance) atomic states is one example of conversion of radiation energy into electrical one. Since spontaneous fluorescence of excited atoms is probabilistic, the description of the radiating quantized system evolution along with photons energy transfer in a cold atoms medium, should include elements of stochastic dynamics. Finally, the chaotic dynamics of a weakly bound Rydberg electron over a grid of the energy levels diagram of a quasi-molecular Rydberg complex provides an excitation migration of the electron forward to the ionization continuum. This work aims at discussing the specific features of the dynamic resonances formalism in the description of processes involving Rydberg states of an excited atom, including features in the fluorescence spectrum partially caused by the quantum defect control due to ...
Nuclear excitation by positron annihilation with bound electrons in a screened atomic potential
Energy Technology Data Exchange (ETDEWEB)
Kaliman, Zoran E-mail: norlic@mapef.pefri.hr; Orlic, Nada
2001-06-01
We have calculated the total cross section for the process of nuclear excitation in positron-bound electron annihilation. The calculations presented in this work use a spherically symmetric screened atomic potential. Comparisons with more approximate treatments of the process are made. (author)
International Nuclear Information System (INIS)
We investigate weakly bound dyon-fermion states of the lowest angular momentum. Both Coulomb attraction and Coulomb repulsion are studied. Binding energies are given by a transcendental equation which is solved explicitly in a number of limiting cases.Normalized wave functions are given in terms of Bessel functions and confluent hypergeometric functions. (orig.)
Atomic Fock State Preparation Using Rydberg Blockade
Ebert, Matthew; Gibbons, Michael; Zhang, Xianli; Saffman, Mark; Walker, Thad G
2013-01-01
We use coherent excitation of 3-16 atom ensembles to demonstrate collective Rabi flopping mediated by Rydberg blockade. Using calibrated atom number measurements, we quantitatively confirm the expected $\\sqrt{N}$ Rabi frequency enhancement to within 4%. The resulting atom number distributions are consistent with essentially perfect blockade. We then use collective Rabi $\\pi$ pulses to produce ${\\cal N}=1,2$ atom number Fock states with fidelities of 62% and 48% respectively. The ${\\cal N}=2$ Fock state shows the collective Rabi frequency enhancement without corruption from atom number fluctuations.
Schwinger functions, light-quark bound states and sigma terms
Höll, A.; Maris, P.; Roberts, C. D.; Wright, S. V.
2006-11-01
We explore the viability of using solely spacelike information about a Schwinger function to extract properties of bound states. In a concrete example it is not possible to determine properties of states with masses ≳1.2 GeV. Modern Dyson-Schwinger equation methods supply a well-constrained tool that provides access to hadron masses and σ-terms. We report values of the latter for a range of hadrons. Of interest is an analysis relating to a u,d scalar meson, which is compatible with a picture of the lightest 0 as a bound state of a dressed-quark and -antiquark supplemented by a material pion cloud. A constituent-quark σ-term is defined, which affords a means for assessing the flavour-dependence of dynamical chiral symmetry breaking.
Bound States in the Continuum in double layer structures
Li, Liangsheng; Yin, Hongcheng
2016-06-01
We have theoretically investigated the reflectivity spectrums of single- and double-layer photonic crystal slabs and the dielectric multilayer stack. It is shown that light can be perfectly confined in a single-layer photonic crystal slab at a given incident angle by changing the thickness, permittivity or hole radius of the structure. With a tunable double-layer photonic crystal slab, we demonstrate that the occurrence of tunable bound states in the continuum is dependent on the spacing between two slabs. Moreover, by analytically investigating the Drude lossless multilayer stack model, the spacing dependence of bound states in the continuum is characterized as the phase matching condition that illuminates these states can occur at any nonzero incident angles by adjusting the spacing.
Andreev bound state spectrum in half-metallic ferromagnets
International Nuclear Information System (INIS)
Half-metallic ferromagnets are important for potential applications in spintronics and as sources of completely spin-polarized currents. In heterostructures with superconductors they introduce new effects in the interface regions, like spin-mixing and triplet rotation. A triplet supercurrent trough a half metal has been predicted and experimentally verified. Another interesing question regards the question how the density of states is modified in the half-metallic region. Here we present results of the Andreev bound state spectrum in a half-metal/superconductor proximity structure. We discuss the dependence on the interface parameters that enter the interface scattering matrix of the heterostructure. We discuss the role of odd-frequency pairing amplitudes in the proximity structure. We also study the modification of the Andreev bound state spectrum in a superflow
Shooting quasiparticles from Andreev bound states in a superconducting constriction
Energy Technology Data Exchange (ETDEWEB)
Riwar, R.-P.; Houzet, M.; Meyer, J. S. [University of Grenoble Alpes, INAC-SPSMS (France); Nazarov, Y. V., E-mail: Y.V.Nazarov@tudelft.nl [Delft University of Technology, Kavli Institute of NanoScience (Netherlands)
2014-12-15
A few-channel superconducting constriction provides a set of discrete Andreev bound states that may be populated with quasiparticles. Motivated by recent experimental research, we study the processes in an a.c. driven constriction whereby a quasiparticle is promoted to the delocalized states outside the superconducting gap and flies away. We distinguish two processes of this kind. In the process of ionization, a quasiparticle present in the Andreev bound state is transferred to the delocalized states leaving the constriction. The refill process involves two quasiparticles: one flies away while another one appears in the Andreev bound state. We notice an interesting asymmetry of these processes. The electron-like quasiparticles are predominantly emitted to one side of the constriction while the hole-like ones are emitted to the other side. This produces a charge imbalance of accumulated quasiparticles, that is opposite on opposite sides of the junction. The imbalance may be detected with a tunnel contact to a normal metal lead.
Are there compact heavy four-quark bound states?
Vijande, Javier; Weissman, E.; Valcarce, A.; Barnea, N.
2007-01-01
We present an exact method to study four-quark systems based on the hyperspherical harmonics formalism. We apply it to several physical systems of interest containing two heavy and two light quarks using different quark-quark potentials. Our conclusions mark the boundaries for the possible existence of compact, nonmolecular, four-quark bound states. While QQ (n) over bar(n) over bar states may be stable in nature, the stability of Q (Q) over barn (n) over bar states would imply the existence ...
International Nuclear Information System (INIS)
This chapter presents the final lecture given at the Eighth International Conference on Atomic Physics held in Sweden in 1982. Discusses (in general terms) new tools, positron investigations, quantum electrodynamics, physical metaphors, Bell's inequalities, quantum mechanics, precision measurements, sensitivity, high-resolution laser spectroscopy, and the theoretical papers given at the conference. Concludes that there are gaps in atomic physics which need to be filled
A variational study of bound states in the Higgs model
Siringo, F
2000-01-01
The possible existence of Higgs-Higgs bound states in the Higgs sector of the Standard Model is explored using the |hh>+|hhh> variational ansatz of Di Leo and Darewych. The resulting integral equations can be decoupled exactly, yielding a one-dimensional integral equation, solved numerically. We thereby avoid the extra approximations employed by Di Leo and Darewych, and we find a qualitatively different mass renormalization. Within the conventional scenario, where a not-too-large cutoff is invoked to avoid "triviality", we find, as usual, an upperbound on the Higgs mass. Bound-state solutions are only found in the very strong coupling regime, but at the same time a relatively small physical mass is required as a consequence of renormalization.
Observation of Andreev bound states at spin-active interfaces
Energy Technology Data Exchange (ETDEWEB)
Beckmann, Detlef; Wolf, Michael Johannes [KIT, Institut fuer Nanotechnologie (Germany); Huebler, Florian [KIT, Institut fuer Nanotechnologie (Germany); KIT, Institut fuer Festkoerperphysik (Germany); Loehneysen, Hilbert von [KIT, Institut fuer Festkoerperphysik (Germany); KIT, Physikalisches Institut (Germany)
2013-07-01
We report on high-resolution differential conductance experiments on nanoscale superconductor/ferromagnet tunnel junctions with ultra-thin oxide tunnel barriers. We observe subgap conductance features which are symmetric with respect to bias, and shift according to the Zeeman energy with an applied magnetic field. These features can be explained by resonant transport via Andreev bound states induced by spin-active scattering at the interface. From the energy and the Zeeman shift of the bound states, both the magnitude and sign of the spin-dependent interfacial phase shifts between spin-up and spin-down electrons can be determined. These results contribute to the microscopic insight into the triplet proximity effect at spin-active interfaces.
Bound states in coupled guides. II. Three dimensions
Linton, C. M.; Ratcliffe, K.
2004-04-01
We compute bound-state energies in two three-dimensional coupled waveguides, each obtained from the two-dimensional configuration considered in paper I [J. Math. Phys. 45, 1359-1379 (2004)] by rotating the geometry about a different axis. The first geometry consists of two concentric circular cylindrical waveguides coupled by a finite length gap along the axis of the inner cylinder, and the second is a pair of planar layers coupled laterally by a circular hole. We have also extended the theory for this latter case to include the possibility of multiple circular windows. Both problems are formulated using a mode-matching technique, and in the cylindrical guide case the same residue calculus theory as used in paper I is employed to find the bound-state energies. For the coupled planar layers we proceed differently, computing the zeros of a matrix derived from the matching analysis directly.
Bound States in Minkowski Space in 2 + 1 Dimensions
International Nuclear Information System (INIS)
The Nakanishi perturbative integral representation of the Bethe–Salpeter amplitude in three-dimensions (2 + 1) is used to solve the corresponding homogeneous Bethe–Salpeter equation in Minkowski space. The projection of this equation onto the null-plane, as reported here, leads to a bound-state equation for the Nakanishi weight function. The explicit forms of the integral equation for the Nakanishi weight function are shown in the ladder approximation. In addition, the valence light-front wave function is presented. The formal steps of the formalism are illustrated to some extend, with the resulting equation being applied to a bound state system composed by two identical scalar particles of mass m, interacting through the exchange of another massive scalar particle of mass μ. The results reported in this contribution show quite good agreement between our calculations obtained from the Bethe–Salpeter amplitude with the Nakanishi weight function with direct solutions obtained in the Euclidean space. (author)
Understanding the nucleon as a Borromean bound-state
Directory of Open Access Journals (Sweden)
Jorge Segovia
2015-11-01
Full Text Available Analyses of the three valence-quark bound-state problem in relativistic quantum field theory predict that the nucleon may be understood primarily as a Borromean bound-state, in which binding arises mainly from two separate effects. One originates in non-Abelian facets of QCD that are expressed in the strong running coupling and generate confined but strongly-correlated colour-antitriplet diquark clusters in both the scalar–isoscalar and pseudovector–isotriplet channels. That attraction is magnified by quark exchange associated with diquark breakup and reformation. Diquark clustering is driven by the same mechanism which dynamically breaks chiral symmetry in the Standard Model. It has numerous observable consequences, the complete elucidation of which requires a framework that also simultaneously expresses the running of the coupling and masses in the strong interaction. Planned experiments are capable of validating this picture.
Bound States in the Continuum in Nuclear and Hadron Physics
Lenske, H; Cao, Xu
2015-01-01
The population of bound states in the continuum and their spectral properties are studied on the nuclear and hadronic scale. The theoretical approach is presented and realizations in nuclear and charmonium spectroscopy are dis- cussed. The universality of the underlying dynamical principles is pointed out. Applications to nuclear systems at the neutron dripline and for charmonium spectroscopy by $e^- e^+ \\to D\\bar{D}$ production are discussed.
Weakly bound states of neutrons in gravitational fields
Khugaev, Avas V.; Sultanov, Renat A.; Guster, Dennis
2010-01-01
In this paper a quantum-mechanical behaviour of neutrons in gravitational fields is considered. A first estimation is made using the semiclassical approximation, neglecting General Relativity, magnetic and rotation effects, for neutrons in weakly bound states in the weak gravitational field of the Earth. This result was generalized for a case, in which the Randall - Sundrum correction to Newton's gravitational law on the small scales was applied. Application of the results to Neutron Star phy...
Approximate bound Dirac states for pseudoscalar Hulthen potential
International Nuclear Information System (INIS)
In this paper, we present approximate analytical solutions of the Dirac equation with the pseudoscalar Hulthen potential under spin and pseudospin (p-spin) symmetry limits in (3+1) dimensions. The energy eigenvalues and corresponding eigenfunctions are given in their closed forms by using the Nikiforov–Uvarov (NU) method. Numerical results of the energy eigenvalue equations are presented to show the effects of the potential parameters on the bound-state energies. (author)
Bound states in weakly deformed waveguides: numerical vs analytical results
Amore, Paolo; Fernández, Francisco M; Jacobo, Martin; Zhevandrov, Petr
2016-01-01
We have studied the emergence of bound states in weakly deformed and/or heterogeneous waveguides, comparing the analytical predictions obtained using a recently developed perturbative method, with precise numerical results, for different configurations (a homogeneous asymmetric waveguide, a heterogenous asymmetric waveguide and a homogeneous broken-strip). In all the examples considered in this paper we have found excellent agreement between analytical and numerical results, thus providing a numerical verification of the analytical approach.
Fermion Bound States Around Skyrmions in Doped Antiferromagnets
Institute of Scientific and Technical Information of China (English)
寇谡鹏
2003-01-01
We show the skyrmion effects in doped antiferromagnets for the uniform flux phase. The low-energy effective theory of the t′-J model can be mapped onto the massive quantum electrodynamics. There exist Fermion bound states around skyrmions. For each sublattice, there exist induced fractional fermion numbers around the skyrmions. The total induced fermion number is zero due to the "cancelling effect" between two sublattices with opposite charges.
Atom-field dressed states in slow-light waveguide QED
Calajó, Giuseppe; Ciccarello, Francesco; Chang, Darrick; Rabl, Peter
2016-03-01
We discuss the properties of atom-photon bound states in waveguide QED systems consisting of single or multiple atoms coupled strongly to a finite-bandwidth photonic channel. Such bound states are formed by an atom and a localized photonic excitation and represent the continuum analog of the familiar dressed states in single-mode cavity QED. Here we present a detailed analysis of the linear and nonlinear spectral features associated with single- and multiphoton dressed states and show how the formation of bound states affects the waveguide-mediated dipole-dipole interactions between separated atoms. Our results provide both a qualitative and quantitative description of the essential strong-coupling processes in waveguide QED systems, which are currently being developed in the optical and microwave regimes.
Individual Atoms in their Quantum Ground State
Schwartz, Eyal; Sompet, Pimonpan; Fung, Yin Hsien; Andersen, Mikkel F.
2016-05-01
An ultimate control of pure quantum states is an excellent platform for various quantum science and engineering. In this work, we perform quantum manipulation of individual Rubidium atoms in a tightly focus optical tweezer in order to cool them into their vibrational ground state via Raman sideband cooling. Our experimental scheme involves a combination of Raman sideband transitions and optical pumping of the atoms that couples two magnetic field sublevels indifferent to magnetic noise thus providing a much longer atomic coherence time compared to previous cooling schemes. By installing most of the atoms in their ground state, we managed to achieve two-dimensional cooling on the way to create a full nil entropy quantum state of single atoms and single molecules. We acknowledge the Marsden Fund, CORE and DWC for their support.
Two-body bound states & the Bethe-Salpeter equation
Energy Technology Data Exchange (ETDEWEB)
Pichowsky, M. [Argonne National Lab., IL (United States); Kennedy, M. [Univ. of New Hampshire, Durham, NH (United States). Physics Dept.; Strickland, M. [Duke Univ., Durham, NC (United States)
1995-01-18
The Bethe-Salpeter formalism is used to study two-body bound states within a scalar theory: two scalar fields interacting via the exchange of a third massless scalar field. The Schwinger-Dyson equation is derived using functional and diagrammatic techniques, and the Bethe-Salpeter equation is obtained in an analogous way, showing it to be a two-particle generalization of the Schwinger-Dyson equation. The authors also present a numerical method for solving the Bethe-Salpeter equation without three-dimensional reduction. The ground and first excited state masses and wavefunctions are computed within the ladder approximation and space-like form factors are calculated.
Upsilon particles as bound states of new heavy quarks
International Nuclear Information System (INIS)
Charmonium spectroscopy (cc) was analysed, recently using a power confining potential and was determined that the energy eigenvalues are in good agreement with experimental values when it was used a power equal to 1/2 (square root potential). Assuming universality of the potential for quark-antiquark (qq) and assuming that the particle γ (9.4 GeV) is the fundamental state of the pair bb (beauty quark). The remaning bound states of this pair and their leptonic and hadronic decay widths are calculated
Three-boson bound states in finite volume with EFT
International Nuclear Information System (INIS)
The universal properties of a three-boson system with large scattering length are well understood within the framework of Effective Field Theory. They include a geometric spectrum of shallow three-body bound states called Efimov states and log-periodic dependence of scattering observables on the scattering length. We investigate the modification of this spectrum in a finite cubic box using a partial wave expansion. The dependence of the binding energies on the box size is calculated and the renormalization of the Effective Field Theory in finite volume is verified explicitly.
Bound states in continuum: Quantum dots in a quantum well
International Nuclear Information System (INIS)
We report on the existence of a bound state in the continuum (BIC) of quantum rods (QR). QRs are novel elongated InGaAs quantum dot nanostructures embedded in the shallower InGaAs quantum well. BIC appears as an excited confined dot state and energetically above the bottom of a well subband continuum. We prove that high height-to-diameter QR aspect ratio and the presence of a quantum well are indispensable conditions for accommodating the BIC. QRs are unique semiconductor nanostructures, exhibiting this mathematical curiosity predicted 83 years ago by Wigner and von Neumann.
Analytic continuation as a bridge between continuum and bound states
Directory of Open Access Journals (Sweden)
Blokhintsev Leonid
2015-01-01
Full Text Available The problem of obtaining characteristics of bound nuclear states from continuum states data is discussed. It is shown that the ambiguities due to the existence of phase-equivalent potentials can be resolved by using the analytic properties of scattering amplitudes. The methods of determination of asymptotic normalization coefficients and vertex constants are considered. The asymptotic normalization coefficients for 6Li in the α + d channel are found by analytic continuation of the two-channel effective range expansion. The account of inelastic channels within the effective range approach is discussed.
Photo-production of Bound States with Hidden Charms
Wu, Jia-Jun
2012-01-01
The photo-production of $J/\\Psi$-$^3He$ bound state ($[^3He]_{J/\\Psi}$) on a $^4He$ target has been investigated using the impulse approximation. The calculations have been performed using several $\\gamma+N \\rightarrow J/\\Psi +N$ models based on the Pomeron-exchange and accounting for the pion-exchange mechanism at low energies. The $J/\\Psi$ wavefunctions in $[^3He]_{J/\\Psi}$ are generated from various $J/\\Psi$-nucleus potentials which are constructed by either using a procedure based on the Pomeron-quark coupling mechanism or folding a $J/\\Psi$-N potential ($v_{J/\\Psi,N}$) into the nuclear densities. We consider $v_{J/\\Psi,N}$ derived from the effective field theory approach, Lattice QCD, and Pomeron-quark coupling mechanism. The upper bound of the predicted total cross sections is about $0.1 - 0.3$ pico-barn. We also consider the possibility of photo-production of a six quark-$J/\\Psi$ bound state ($[q^6]_{J/\\Psi})$ on the $^3He$ target. The Compound Bag Model of $NN$ scattering and the quark cluster model o...
Accurate calculations of bound rovibrational states for argon trimer
Energy Technology Data Exchange (ETDEWEB)
Brandon, Drew; Poirier, Bill [Department of Chemistry and Biochemistry, and Department of Physics, Texas Tech University, Box 41061, Lubbock, Texas 79409-1061 (United States)
2014-07-21
This work presents a comprehensive quantum dynamics calculation of the bound rovibrational eigenstates of argon trimer (Ar{sub 3}), using the ScalIT suite of parallel codes. The Ar{sub 3} rovibrational energy levels are computed to a very high level of accuracy (10{sup −3} cm{sup −1} or better), and up to the highest rotational and vibrational excitations for which bound states exist. For many of these rovibrational states, wavefunctions are also computed. Rare gas clusters such as Ar{sub 3} are interesting because the interatomic interactions manifest through long-range van der Waals forces, rather than through covalent chemical bonding. As a consequence, they exhibit strong Coriolis coupling between the rotational and vibrational degrees of freedom, as well as highly delocalized states, all of which renders accurate quantum dynamical calculation difficult. Moreover, with its (comparatively) deep potential well and heavy masses, Ar{sub 3} is an especially challenging rare gas trimer case. There are a great many rovibrational eigenstates to compute, and a very high density of states. Consequently, very few previous rovibrational state calculations for Ar{sub 3} may be found in the current literature—and only for the lowest-lying rotational excitations.
Accurate calculations of bound rovibrational states for argon trimer
International Nuclear Information System (INIS)
This work presents a comprehensive quantum dynamics calculation of the bound rovibrational eigenstates of argon trimer (Ar3), using the ScalIT suite of parallel codes. The Ar3 rovibrational energy levels are computed to a very high level of accuracy (10−3 cm−1 or better), and up to the highest rotational and vibrational excitations for which bound states exist. For many of these rovibrational states, wavefunctions are also computed. Rare gas clusters such as Ar3 are interesting because the interatomic interactions manifest through long-range van der Waals forces, rather than through covalent chemical bonding. As a consequence, they exhibit strong Coriolis coupling between the rotational and vibrational degrees of freedom, as well as highly delocalized states, all of which renders accurate quantum dynamical calculation difficult. Moreover, with its (comparatively) deep potential well and heavy masses, Ar3 is an especially challenging rare gas trimer case. There are a great many rovibrational eigenstates to compute, and a very high density of states. Consequently, very few previous rovibrational state calculations for Ar3 may be found in the current literature—and only for the lowest-lying rotational excitations
Hydrogen atom in 2s state in a laser field
Directory of Open Access Journals (Sweden)
Vučić Svetlana
2012-01-01
Full Text Available The hydrogen atom in the 2s state exposed to a linearly polarized laser field is studied by using the non-perturbative non-Hermitian Floquet theory. The electronic density of the quasi-energy H(2s state versus the electron coordinate is analyzed. We conclude that the decay of an atom in a low-intensity non-resonant laser field occurs from the asymptotically distant part of the initial state. On the other hand, the process of electron emission in a resonant laser field is governed by the excited-bound-statepart of the resonance wave function. With an increase in the intensity and by increasing the degree of excitation of the initial state not too high, the electron is ionized at smaller distances from the nucleus. [Projekat Ministarstva nauke Republike Srbije, br. 171020
Upper bound on the equilibrium concentration of atomic H in solid H2
Rosen, G.
1977-01-01
A phenomenological rate process theory has been developed for the production, storage and recombination of atomic H free radicals in a tritium-impregnated solid H2 at temperatures in the range of about 0.1 to 4 K. In this paper it is shown that the theory requires a stringent upper bound on the equilibrium concentration of trapped atomic H, namely that it cannot exceed about 0.125%, even if the temperature is reduced to an arbitrary low value and a very strong magnetic field is applied to the tritium-impregnated H2 solid.
Observation of the continuous stern-gerlach effect on an electron bound in an atomic Ion
Hermanspahn; Haffner; Kluge; Quint; Stahl; Verdu; Werth
2000-01-17
We report on the first observation of the continuous Stern-Gerlach effect on an electron bound in an atomic ion. The measurement was performed on a single hydrogenlike ion ( 12C5+) in a Penning trap. The measured g factor of the bound electron, g = 2.001 042(2), is in excellent agreement with the theoretical value, confirming the relativistic correction at a level of 0.1%. This proves the possibility of g-factor determinations on atomic ions to high precision by using the continuous Stern-Gerlach effect. The result demonstrates the feasibility of conducting experiments on single heavy highly charged ions to test quantum electrodynamics in the strong electric field of the nucleus. PMID:11015930
Molecular Andreev bound states and Majorana modes in a double dot system
Vernek, Edson; Silva, Joelson F.
Nanostructured systems such as quantum dots (QD) connected to superconductors has attracted a lot of attention in the recent years. One of the well known phenomena in such a system is the formation of a pair of bound called Andreev bound states (ABS). Recently, it have been shown that when a QD is coupled to a topological superconductor wire, a Majorana bound state (MBS) leaks from the end of the wire into the dot. The character of these bound states is much reacher in structures like molecules and is far from being completely understood. In this work we study a system composed by a two inter-connected QDs in which one of then is coupled to a normal superconductor and to a normal lead while the other is coupled to a topological superconductor and to a distinct normal metallic lead. We show that in the atomic limit (for small interdot coupling), one of the dot has a pair of ABS whereas the other has a single a MBS. More interestingly, in the molecular regime (large inter-dot coupling) we observe a localized Majorana mode coexisting with a delocalized molecular ABS. We would like to thank financial support from the Brazilian agencies CNPq, CAPES and FAPEMIG.
State labelling Wannier-Stark atomic interferometers
Pelle B.; Hilico A.; Tackmann G.; Beaufils Q.; Pereira Dos Santos F.
2013-01-01
Using cold 87Rb atoms trapped in a 1D-optical lattice, atomic interferometers involving coherent superpositions between different Wannier-Stark atomic states are realized. Two di fferent kinds of trapped interferometer schemes are presented: a Ramsey-type interferometer sensitive both to clock frequency and external forces, and a symmetric accordion-type interferometer, sensitive to external forces only. We evaluate the limits in terms of sensitivity and accuracy of those schemes and discuss ...
Colour-octet bound states, induced by Higgs mechanism
Bladwell, S; Flambaum, V V; Kozlov, A
2012-01-01
The current limits for fourth generation quarks allows to expect their mass of the order of 500 GeV. In this mass region for quark-anti-quark pair the additional Yukawa-type attraction due to Higgs mechanism is expected to emerge. This Higgs induced attraction greatly exceeds strong interaction between quarks and leads to the formation of bound states in both colour octet $S^{(8)}$ and singlet $S^{(1)}$ states. In the key of recent works on significance of colour octet channel for production of colour singlet state of fourth generation $Q\\bar{Q}$ we calculated the binding energies for both octet and singlet states. Such attraction localizes quarks in extremely small area. Hence colour octet pair of fourth generation quarks can form the "nucleus" and together with colour neutralizing light particle that is captured by strong interaction in orbit around the nucleus, create particle, similar by its structure to Deuterium.
A narrow quasi-bound state of the DNN system
International Nuclear Information System (INIS)
We have investigated a charmed system of DNN (composed of two nucleons and a D meson) by a complementary study with a variational calculation and a Faddeev calculation with fixed-center approximation (Faddeev-FCA). In the present study, we employ a DN potential based on a vector–meson exchange picture in which a resonant Λc(2595) is dynamically generated as a DN quasi-bound state, similarly to the Λ(1405) as a K¯N one in the strange sector. As a result of the study of variational calculation with an effective DN potential and three kinds of NN potentials, the DNN(Jπ=0−,I=1/2) is found to be a narrow quasi-bound state below Λc(2595)N threshold: total binding energy ∼225 MeV and mesonic decay width ∼25 MeV. On the other hand, the Jπ=1− state is considered to be a scattering state of Λc(2595) and a nucleon. These results are essentially supported by the Faddeev-FCA calculation. By the analysis of the variational wave function, we have found a unique structure in the DNN(Jπ=0−,I=1/2) such that the D meson stays around the center of the total system due to the heaviness of the D meson
Quantum State Reconstruction Using Atom Optics
Varcoe, B. T. H.; Sang, R. T.; MacGillivray, W. R.; Stadage, M C
1999-01-01
We present a novel technique in which the total internal quantum state of an atom may be reconstructed via the measurement of the momentum transferred to an atom following its interaction with a near resonant travelling wave laser beam. We present the first such measurement and demonstrate the feasibility of the technique.
Schroedinger cat states and multilevel atoms
International Nuclear Information System (INIS)
We demonstrate that the generalization of the two-level Jaynes-Cummings model (JCM) to an N-level atom leads to the creation of up to N macroscopically distinct field states. These field states are Schmidt-orthogonalized superpositions of Fock states. They correspond to macroscopic states of the field, attainable with large mean photon numbers. Unlike the situation with a two-level atom and a coherent-state field, which evolves into a macroscopic coherent superposition state (a Schrodinger cat), we find that when the additional levels participate strongly in the excitation (e.g all transitions are resonant with equal dipole moments) then the system does not evolve into a pure state. We will present some examples of special cases, giving insight into the behavior of three-level atoms and the two-level two-photon JCM
Cavity cooling and normal-mode spectroscopy of a bound atom-cavity system
International Nuclear Information System (INIS)
Full text: Single atoms strongly coupled to the field of an optical cavity form an attractive system for the realization of an atom-light interface useful for quantum information protocols. An experimental implementation of these schemes requires atoms which are trapped, cooled and localized in the cavity mode at a region of strong coupling. In the experiment presented here, single atoms are trapped and stored in a far-detuned intracavity dipole trap. We demonstrate cavity cooling by illuminating the system with a weak, slightly blue-detuned light beam. This extends the storage time of an atom, which is limited by parametric heating from fluctuations of the intracavity dipole trap, by more than a factor of two. The observed cooling force is of Sisyphus-type and was predicted. A special feature of this force is that it does not rely on the spontaneous emission of a photon by the atom, and therefore the cooling force is at least five times larger than the force achievable for free-space cooling methods with comparable excitation of a two-level atom. Preparing single atoms strongly-coupled to the mode of a high-finesse cavity in this way, we observe two well-resolved normal-mode peaks both in transmission of the cavity as well as in the trap lifetime. The experimental data agree well with a Monte Carlo simulation, demonstrating the localization of the atom to within a tenth of a wavelength at a cavity antinode. The ability to individually excite the normal modes of a bound atom-cavity system shows that we have reached good control over this fundamental quantum system. (author)
Static and dynamic properties of QCD bound states
International Nuclear Information System (INIS)
The QCD phenomenology can be faced with the framework of the coupled quark DSE, meson BSE and baryon Faddeev equation, providing non-perturbative, continuum and Poincare invariant scientific approach. The research performed throughout this thesis is twofold. From one perspective we focus on the investigation of mass spectra for mesons with total spin quantum number J=3 and arising Regge-trajectory for natural parity states JPC=1--,2++,3-- within rainbow-ladder single gluon exchange model. The other findings are concerning the impact of the pion cloud effect on J>2 meson states, baryon masses, namely on Nucleon and Delta three-body bound states and meson dynamical properties like the pion form factor.
Static and dynamic properties of QCD bound states
Energy Technology Data Exchange (ETDEWEB)
Kubrak, Stanislav
2015-07-01
The QCD phenomenology can be faced with the framework of the coupled quark DSE, meson BSE and baryon Faddeev equation, providing non-perturbative, continuum and Poincare invariant scientific approach. The research performed throughout this thesis is twofold. From one perspective we focus on the investigation of mass spectra for mesons with total spin quantum number J=3 and arising Regge-trajectory for natural parity states J{sup PC}=1{sup --},2{sup ++},3{sup --} within rainbow-ladder single gluon exchange model. The other findings are concerning the impact of the pion cloud effect on J>2 meson states, baryon masses, namely on Nucleon and Delta three-body bound states and meson dynamical properties like the pion form factor.
The inverse problem in the case of bound states
International Nuclear Information System (INIS)
We investigate the inverse problem for bound states in the D = 3 dimensional space. The potential is assumed to be local and spherically symmetric. The present method is based on relationships connecting the moments of the ground state density to the lowest energy of each state of angular momentum l. The reconstruction of the density ρ(r) from its moments is achieved by means of the series expansion of its Fourier transform F(q). The large q-behavior is described by Pade approximants. The accuracy of the solution depends on the number of known moments. The uniqueness is achieved if this number is infinite. In practice, however, an accuracy better than 1% is obtained with a set of about 15 levels. The method is tested on a simple example, and applied to three different spectra
The search for deeply bound kaonic states with FOPI
International Nuclear Information System (INIS)
Full text: New formation mechanisms for the creation of dense, exotic nuclear systems involving strangeness were recently proposed by Y. Akaishi and T. Yamazaki. Their calculations show that a K- might form deeply bound states in light nuclei - so called kaonic clusters - with central densities of several times the normal nuclear density. In the presentation a short overview of these exotic nuclear systems will be given and a new experiment with FOPI at GSI will be discussed. The aim of this experiment was to search for the simplest cluster - a ppK- state. This state is produced at GSI in the following high energy reaction: p + ''d'' → ppK- + K+ + n'' with incident energies of 3.5 GeV. The experimental set-up will be presented in detail. (author)
Autodetachment spectroscopy of the aluminum oxide anion dipole bound state
Energy Technology Data Exchange (ETDEWEB)
Mascaritolo, Kyle J.; Gardner, Adrian M.; Heaven, Michael C., E-mail: mheaven@emory.edu [Department of Chemistry, Emory University, Atlanta, Georgia 30322 (United States)
2015-09-21
The {sup 1}Σ{sup +}←X{sup 1}Σ{sup +} ground state to dipole bound state (DBS) electronic transition of AlO{sup −} has been studied by means of autodetachment spectroscopy. Vibrational and rotational molecular constants for AlO{sup −} have been determined for both the ground state (υ″ = 0, 1) and the excited DBS (υ′ = 0, 1). These data provide an improved determination of the electron affinity for AlO (2.6110(7) eV) that is consistent with an earlier measurement. The electron binding energy of the DBS was found to be 52 ± 6 cm{sup −1}. Experimental results are compared with the predictions from high level ab initio calculations.
Configuration space Faddeev formalism: Λ + n + n bound state search
Suslov, Vladimir; Filikhin, Igor; Vlahovic, Branislav
2015-04-01
The HypHI Collaboration has recently reported the evidence for bound state of Λ + n + n system (Phys. Rev. C 88, 041001(R) (2013)). However, the theoretical analysis did not find Λ3n bound state (see, for instance, Phys. Lett. B 736, 93 (2014)). In the present work we will describe our attempt to construct a phenomenological three-body ΛNN force with the spin-isospin dependence that is attractive in the channel T=1, S=1/2. This dependence was tested to reproduce the value of ground state energy for Λ3H hypernuclei. The formalism of the configuration-space Faddeev equations is applied for Λ + n + n and Λ + n + p systems. As Λ + n interaction the s-wave potential simulating model NSC97f is used. This potential reproduces well the hyperon binding energy for Λ3H nuclei (J. Phys. G: 31, 389 (2005)). The details of the model and obtained results will be presented. This work is supported by the NSF (HRD-1345219) and NASA (NNX09AV07A).
Tetraquark bound states in a Bethe-Salpeter approach
Heupel, Walter; Eichmann, Gernot; Fischer, Christian S.
2012-01-01
We determine the mass of tetraquark bound states from a coupled system of covariant Bethe-Salpeter equations. Similar in spirit to the quark-diquark model of the nucleon, we approximate the full four-body equation for the tetraquark by a coupled set of two-body equations with meson and diquark constituents. These are calculated from their quark and gluon substructure using a phenomenologically well-established quark-gluon interaction. For the lightest scalar tetraquark we find a mass of the o...
Quarkonium-nucleus bound states from lattice QCD
Energy Technology Data Exchange (ETDEWEB)
Beane, S. R. [Univ. of Washington, Seattle, WA (United States); Chang, E. [Univ. of Washington, Seattle, WA (United States); Cohen, S. D. [Univ. of Washington, Seattle, WA (United States); Detmold, W. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Lin, H. -W. [Univ. of Washington, Seattle, WA (United States); Orginos, K. [College of William and Mary, Williamsburg, VA (United States); Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Parreño, A. [Univ., de Barcelona, Marti Franques (Spain); Savage, M. J. [Univ. of Washington, Seattle, WA (United States)
2015-06-11
Quarkonium-nucleus systems are composed of two interacting hadronic states without common valence quarks, which interact primarily through multi-gluon exchanges, realizing a color van der Waals force. We present lattice QCD calculations of the interactions of strange and charm quarkonia with light nuclei. Both the strangeonium-nucleus and charmonium-nucleus systems are found to be relatively deeply bound when the masses of the three light quarks are set equal to that of the physical strange quark. Extrapolation of these results to the physical light-quark masses suggests that the binding energy of charmonium to nuclear matter is B < 40 MeV.
Resonantly Trapped Bound State in the Continuum Laser
Lepetit, Thomas; Kodigala, Ashok; Bahari, Babak; Fainman, Yeshaiahu; Kanté, Boubacar
2015-01-01
Cavities play a fundamental role in wave phenomena from quantum mechanics to electromagnetism and dictate the spatiotemporal physics of lasers. In general, they are constructed by closing all "doors" through which waves can escape. We report, at room temperature, a bound state in the continuum laser that harnesses optical modes residing in the radiation continuum but nonetheless may possess arbitrarily high quality factors. These counterintuitive cavities are based on resonantly trapped symmetry-compatible modes that destructively interfere. Our experimental demonstration opens exciting avenues towards coherent sources with intriguing topological properties for optical trapping, biological imaging, and quantum communication.
R-Matrix Calculations for Few-Quark Bound States
Shalchi, M A
2016-01-01
The R-matrix method is implemented to study the heavy charm and bottom diquark, triquark, tetraquark and pentaquarks in configuration space, as the bound states of quark-antiquark, diquark-quark, diquark-antidiquark and diquark-antitriquark systems, respectively. The mass spectrum and the size of these systems are calculated for different partial wave channels. The calculated masses are compared with recent theoretical results obtained by %the solution of Lippmann-Schwinger equation other methods in momentum and configuration spaces and also by available experimental data.
Three-body bound states in finite volume with EFT
International Nuclear Information System (INIS)
Three particles with large scattering length display a universal spectrum of three-body bound states called ''Efimov trimers''. We calculate the modification of the Efimov trimers of three identical bosons in a finite cubic box and compute the dependence of their energies on the box size using effective field theory. The renormalization of the effective field theory in the finite volume is explicitly verified. We investigate the effects of partial wave mixing and study the behavior of shallow trimers near the dimer energy. Finally, we present first results for the triton in a finite volume.
International Nuclear Information System (INIS)
Applying perturbative QCD methods recently seen to give a good description of the two-body hadronic decays of the B meson, we address the question of bound-state effects on the decay B→K*γ. Consistent with most analyses, we demonstrate that gluonic penguin diagrams, with photonic bremsstrahlung off a quark, change the decay rate by only a few percent. Using an asymptotic distribution amplitude for the K* and just the standard model, we can obtain a branching ratio of a few x10-5, consistent with the observed rate
Stieltjes electrostatic model interpretation for bound state problems
Indian Academy of Sciences (India)
K V S Shiv Chaitanya
2014-07-01
In this paper, it is shown that Stieltjes electrostatic model and quantum Hamilton Jacobi formalism are analogous to each other. This analogy allows the bound state problem to mimic as unit moving imaginary charges $i\\hbar$, which are placed in between the two fixed imaginary charges arising due to the classical turning points of the potential. The interaction potential between unit moving imaginary charges $i\\hbar$ is given by the logarithm of the wave function. For an exactly solvable potential, this system attains stable equilibrium position at the zeros of the orthogonal polynomials depending upon the interval of the classical turning points.
Bound states of string networks and D-branes
International Nuclear Information System (INIS)
We show the existence of nonthreshold bound states of (p, q) string networks and D3-branes, preserving 1/4 of the full type-IIB supersymmetry, interpreted as string networks 'dissolved' in D3-branes. We also explicitly write down the expression for the mass density of the system and discuss the extension of the construction to other Dp -branes. Differences in our construction of string networks with the ones interpreted as dyons in N=4 gauge theories are also pointed out
International Nuclear Information System (INIS)
The photoassociation dynamics of ultracold lithium atoms controlled by a cut-off pulse has been investigated theoretically by solving numerically the time-dependent Schrödinger equation using the mapped Fourier grid method. The frequency components of the laser pulse close to the atomic resonance are partly cut off. Compared with the typical Gauss-type pulses, the cut-off pulse is helpful to suppress efficiently the weakly bound states and prepare the associated molecules in the lower vibrational states. Especially, the dependence of photoassociation probability on the cut-off position of the laser pulse is explored. (atomic and molecular physics)
Long range coherent magnetic bound states in superconductors
Ménard, Gerbold C.; Guissart, Sébastien; Brun, Christophe; Pons, Stéphane; Stolyarov, Vasily S.; Debontridder, François; Leclerc, Matthieu V.; Janod, Etienne; Cario, Laurent; Roditchev, Dimitri; Simon, Pascal; Cren, Tristan
2015-01-01
The quantum coherent coupling of completely different degrees of freedom is a challenging path towards creating new functionalities for quantum electronics. Usually the antagonistic coupling between spins of magnetic impurities and superconductivity leads to the destruction of the superconducting order. Here we show that a localized classical spin of an iron atom immersed in a superconducting condensate can give rise to new kind of long range coherent magnetic quantum state. In addition to th...
Fingerprints of Majorana Bound States in Aharonov-Bohm Geometry
Tripathi, Krashna Mohan; Das, Sourin; Rao, Sumathi
2016-04-01
We study a ring geometry, coupled to two normal metallic leads, which has a Majorana bound state (MBS) embedded in one of its arms and is threaded by Aharonov-Bohm (A B ) flux ϕ . We show that by varying the A B flux, the two leads go through resonance in an anticorrelated fashion while the resonance conductance is quantized to 2 e2/h . We further show that such anticorrelation is completely absent when the MBS is replaced by an Andreev bound state (ABS). Hence this anti-correlation in conductance when studied as a function of ϕ provides a unique signature of the MBS which cannot be faked by an ABS. We contrast the phase sensitivity of the MBS and ABS in terms of tunneling conductances. We argue that the relative phase between the tunneling amplitude of the electrons and holes from either lead to the level (MBS or ABS), which is constrained to 0 ,π for the MBS and unconstrained for the ABS, is responsible for this interesting contrast in the A B effect between the MBS and ABS.
Topological nature of bound states in the radiation continuum
Zhen, Bo; Lu, Ling; Stone, A Doug; Soljacic, Marin
2014-01-01
Bound states in the continuum (BICs) are unusual solutions of wave equations describing light or matter: they are discrete and spatially bounded, but exist at the same energy as a continuum of states which propagate to infinity. Until recently, BICs were constructed through fine-tuning parameters in the wave equation or exploiting the separability of the wave equation due to symmetry. More recently, BICs that that are both robust and not symmetry-protected (accidental) have been predicted and experimentally realized in periodic structures; the simplest such system is a periodic dielectric slab, which also has symmetry-protected BICs. Here we show that both types of BICs in such systems are vortex centers in the polarization direction of far-field radiation. The robustness of these BICs is due to the existence of conserved and quantized topological charges, defined by the number of times the polarization vectors wind around the vortex centers. Such charges can only be generated or annihilated by making large c...
Bound states and entanglement in the excited states of quantum spin chains
International Nuclear Information System (INIS)
We investigate the entanglement properties of the excited states of the spin- (1/2) Heisenberg (XXX) chain with isotropic antiferromagnetic interactions, by exploiting the Bethe ansatz solution of the model. We consider eigenstates obtained from both real and complex solutions (‘strings’) of the Bethe equations. Physically, the former are states of interacting magnons, whereas the latter contain bound states of groups of particles. We first focus on the situation with few particles in the chain. Using exact results and semiclassical arguments, we derive an upper bound SMAX for the entanglement entropy. This exhibits an intermediate behaviour between logarithmic and extensive, and it is saturated for highly-entangled states. As a function of the eigenstate energy, the entanglement entropy is organized in bands. Their number depends on the number of blocks of contiguous Bethe–Takahashi quantum numbers. In the presence of bound states a significant reduction in the entanglement entropy occurs, reflecting that a group of bound particles behaves effectively as a single particle. Interestingly, the associated entanglement spectrum shows edge-related levels. At a finite particle density, the semiclassical bound SMAX becomes inaccurate. For highly-entangled states SA∝ Lc, with Lc the chord length, signalling the crossover to extensive entanglement. Finally, we consider eigenstates containing a single pair of bound particles. No significant entanglement reduction occurs, in contrast with the few-particle case. (paper)
Programmable solid state atom sources for nanofabrication
Han, Han; Imboden, Matthias; Stark, Thomas; Del Corro, Pablo G.; Pardo, Flavio; Bolle, Cristian A.; Lally, Richard W.; Bishop, David J.
2015-06-01
In this paper we discuss the development of a MEMS-based solid state atom source that can provide controllable atom deposition ranging over eight orders of magnitude, from ten atoms per square micron up to hundreds of atomic layers, on a target ~1 mm away. Using a micron-scale silicon plate as a thermal evaporation source we demonstrate the deposition of indium, silver, gold, copper, iron, aluminum, lead and tin. Because of their small sizes and rapid thermal response times, pulse width modulation techniques are a powerful way to control the atomic flux. Pulsing the source with precise voltages and timing provides control in terms of when and how many atoms get deposited. By arranging many of these devices into an array, one has a multi-material, programmable solid state evaporation source. These micro atom sources are a complementary technology that can enhance the capability of a variety of nano-fabrication techniques.In this paper we discuss the development of a MEMS-based solid state atom source that can provide controllable atom deposition ranging over eight orders of magnitude, from ten atoms per square micron up to hundreds of atomic layers, on a target ~1 mm away. Using a micron-scale silicon plate as a thermal evaporation source we demonstrate the deposition of indium, silver, gold, copper, iron, aluminum, lead and tin. Because of their small sizes and rapid thermal response times, pulse width modulation techniques are a powerful way to control the atomic flux. Pulsing the source with precise voltages and timing provides control in terms of when and how many atoms get deposited. By arranging many of these devices into an array, one has a multi-material, programmable solid state evaporation source. These micro atom sources are a complementary technology that can enhance the capability of a variety of nano-fabrication techniques. Electronic supplementary information (ESI) available: A document containing further information about device characterization
Bound states for non-symmetric evolution Schroedinger potentials
Energy Technology Data Exchange (ETDEWEB)
Corona, Gulmaro Corona [Area de Analisis Matematico y sus Aplicaciones, Universidad Autonoma Metropolitana-Azcapotalco, Atzcapotzalco, DF (Mexico)). E-mail: ccg@correo.azc.uam.mx
2001-09-14
We consider the spectral problem associated with the evolution Schroedinger equation, (D{sup 2}+ k{sup 2}){phi}=u{phi}, where u is a matrix-square-valued function, with entries in the Schwartz class defined on the real line. The solution {phi}, called the wavefunction, consists of a function of one real variable, matrix-square-valued with entries in the Schwartz class. This problem has been dealt for symmetric potentials u. We found for the present case that the bound states are localized similarly to the scalar and symmetric cases, but by the zeroes of an analytic matrix-valued function. If we add an extra condition to the potential u, we can determine these states by an analytic scalar function. We do this by generalizing the scalar and symmetric cases but without using the fact that the Wronskian of a pair of wavefunction is constant. (author)
Bound states for non-symmetric evolution Schroedinger potentials
International Nuclear Information System (INIS)
We consider the spectral problem associated with the evolution Schroedinger equation, (D2+ k2)φ=uφ, where u is a matrix-square-valued function, with entries in the Schwartz class defined on the real line. The solution φ, called the wavefunction, consists of a function of one real variable, matrix-square-valued with entries in the Schwartz class. This problem has been dealt for symmetric potentials u. We found for the present case that the bound states are localized similarly to the scalar and symmetric cases, but by the zeroes of an analytic matrix-valued function. If we add an extra condition to the potential u, we can determine these states by an analytic scalar function. We do this by generalizing the scalar and symmetric cases but without using the fact that the Wronskian of a pair of wavefunction is constant. (author)
The quantum probability equation: I. Bound state perturbation theory
International Nuclear Information System (INIS)
The partial-wave Schroedinger equation with real boundary conditions is recast as an equation for the probability density. When a small additional potential is included, the changes in the bound-state energy eigenvalues are obtained, up to third order in the perturbation, purely in terms of the perturbing potential and the unperturbed probability density. Although the approach is different, our results are equivalent to those derived by Bender (Bender C M 1978 Advanced Mathematical Methods for Scientists and Engineers (New York: McGraw-Hill) p 330). Knowledge of neither the unperturbed energy spectrum nor the wavefunctions of excited states is required. Evaluations of the second-order energy shift are given for some soluble S-wave problems. (author)
Quantum localization and bound-state formation in Bose-Einstein condensates
International Nuclear Information System (INIS)
We discuss the possibility of exponential quantum localization in systems of ultracold bosonic atoms with repulsive interactions in open optical lattices without disorder. We show that exponential localization occurs in the maximally excited state of the lowest energy band. We establish the conditions under which the presence of the upper energy bands can be neglected, determine the successive stages and the quantum phase boundaries at which localization occurs, and discuss schemes to detect it experimentally by visibility measurements. The discussed mechanism is a particular type of quantum localization that is intuitively understood in terms of the interplay between nonlinearity and a bounded energy spectrum.
Quantum state control of trapped Holmium atoms
Hostetter, James; Yip, Christopher; Milner, William; Booth, Donald; Collett, Jeffrey; Saffman, Mark
2016-05-01
Neutral Holmium with its large number of hyperfine ground states provides a promising approach for collective encoding of a multi-qubit register. A prerequisite for collective encoding is the ability to prepare different states in the 128 state hyperfine ground manifold. We report progress towards optical pumping and control of the hyperfine Zeeman state of trapped Ho atoms. Atoms are transferred from a 410.5 nm MOT into a 455 nm optical dipole trap. The atoms can be optically pumped using light driving the ground 6s2 , F = 11 to 6 s 6 p ,F' = 11 transition together with a F = 10 to F' = 11 repumper. Microwave fields are then used to drive transitions to hyperfine levels with 4 <= F <= 11 . Work supported by NSF award PHY-1404357.
Production and decay of scalar stoponium bound states
Drees, Manuel
1994-01-01
In this paper we discuss possible signatures for the production of scalar \\stst\\ (stoponium) bound states \\sigst\\ at hadron colliders, where \\st\\ is the lighter scalar top eigenstate. We first study the decay of \\sigst; explicit expressions are given for all potentially important decay modes. If \\st\\ has unsuppressed two--body decays, they will always overwhelm the annihilation decays of \\sigst. Among the latter, we find that usually either the $gg$ or $hh$ final state dominates, depending on the size of the off--diagonal entry of the stop mass matrix; $h$ is the lighter neutral scalar Higgs boson of the minimal supersymmetric model. If \\msig\\ happens to be close to the mass of one of the neutral scalar Higgs bosons, $Q \\bar{Q}$ final states dominate ($Q=b$ or $t$). \\ww\\ and $ZZ$ final states are subdominant. We argue that $\\sigst \\rightarrow \\gamgam$ decays offer the best signal for stoponium production at hadron colliders. The tevatron should be able to close the light stop window left open by LEP searches,...
Relativistic wave equation for the bound states of a system of interacting particles
International Nuclear Information System (INIS)
A method for obtaining the relativistic wave equation for the bound states of a system of interacting charged particles without consideration of spin is proposed. An expansion of the wave function of the system in a complete basis of orthonormal wave functions of vacuum states for each type of particle is used in this equation. It is shown that this equation contains two types of solutions for a proton + electron system. The first type corresponds to Bohr bound states. Exact expressions are obtained for the energy and Bohr radius of the ground state with consideration of the finite mass of the particles. An influence of the energy of translational motion of the system as a whole on the structure of the atomic levels in the laboratory frame is predicted. This effect is due to the finite value of m/M, and leads to removal of the degeneracy of the levels with respect to orbital angular momentum l, and partial removal of the degeneracy with respect to its projection. The second type of solution represents states of the system with binding energy Eb=M+m-√(|M2-m2|) and an exponential wave function damping radius equal to the Compton wavelength of the electron. A complete description of this state requires consideration of the electronic vacuum polarization
G-factors of hole bound states in spherically symmetric potentials in cubic semiconductors
Miserev, Dmitry; Sushkov, Oleg
2016-03-01
Holes in cubic semiconductors have effective spin 3/2 and very strong spin orbit interaction. Due to these factors properties of hole bound states are highly unusual. We consider a single hole bound by a spherically symmetric potential, this can be an acceptor or a spherically symmetric quantum dot. Linear response to an external magnetic field is characterized by the bound state Lande g-factor. We calculate analytically g-factors of all bound states.
G-factors of hole bound states in spherically symmetric potentials in cubic semiconductors
Miserev, D. S.; Sushkov, O. P.
2015-01-01
Holes in cubic semiconductors have effective spin 3/2 and very strong spin orbit interaction. Due to these factors properties of hole bound states are highly unusual. We consider a single hole bound by a spherically symmetric potential, this can be an acceptor or a spherically symmetric quantum dot. Linear response to an external magnetic field is characterized by the bound state Lande g-factor. We calculate analytically g-factors of all bound states.
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.
Tetra quark bound states in a Bethe-Salpeter approach
Energy Technology Data Exchange (ETDEWEB)
Heupel, Walter; Eichmann, Gernot [Institut fuer Theoretische Physik, Justus-Liebig-Universitaet Giessen, D-35392 Giessen (Germany); Fischer, Christian S., E-mail: christian.fischer@theo.physik.uni-giessen.de [Institut fuer Theoretische Physik, Justus-Liebig-Universitaet Giessen, D-35392 Giessen (Germany); GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Planckstr. 1, D-64291 Darmstadt (Germany)
2012-12-05
We determine the mass of tetraquark bound states from a coupled system of covariant Bethe-Salpeter equations. Similar in spirit to the quark-diquark model of the nucleon, we approximate the full four-body equation for the tetraquark by a coupled set of two-body equations with meson and diquark constituents. These are calculated from their quark and gluon substructure using a phenomenologically well-established quark-gluon interaction. For the lightest scalar tetraquark we find a mass of the order of 400 MeV and a wave function dominated by the pion-pion constituents. Both results are in agreement with a meson molecule picture for the f{sub 0}(600). Our results furthermore suggest the presence of a potentially narrow all-charm tetraquark in the mass region 5-6 GeV.
Tetraquark bound states in a Bethe-Salpeter approach
Heupel, Walter; Fischer, Christian S
2012-01-01
We determine the mass of tetraquark bound states from a coupled system of covariant Bethe-Salpeter equations. Similar in spirit to the quark-diquark model of the nucleon, we approximate the full four-body equation for the tetraquark by a coupled set of two-body equations with meson and diquark constituents. These are calculated from their quark and gluon substructure using a phenomenologically well-established quark-gluon interaction. For the lightest scalar tetraquark we find a mass of the order of 400 MeV and a wave function dominated by the pion-pion constituents. Both results are in agreement with a meson molecule picture for the f_0(600). Our results furthermore suggest the presence of a potentially narrow all-charm tetraquark in the mass region 5-6 GeV.
Tetraquark bound states in a Bethe-Salpeter approach
Heupel, Walter; Eichmann, Gernot; Fischer, Christian S.
2012-12-01
We determine the mass of tetraquark bound states from a coupled system of covariant Bethe-Salpeter equations. Similar in spirit to the quark-diquark model of the nucleon, we approximate the full four-body equation for the tetraquark by a coupled set of two-body equations with meson and diquark constituents. These are calculated from their quark and gluon substructure using a phenomenologically well-established quark-gluon interaction. For the lightest scalar tetraquark we find a mass of the order of 400 MeV and a wave function dominated by the pion-pion constituents. Both results are in agreement with a meson molecule picture for the f0 (600). Our results furthermore suggest the presence of a potentially narrow all-charm tetraquark in the mass region 5-6 GeV.
Bound-state properties from field-theory correlators
Melikhov, Dmitri
2011-01-01
We discuss the details of calculating hadron properties from the OPE for correlators of quark currents in QCD, which constitutes the basis of the method of QCD sum rules. The main emphasis is laid on gaining control over the systematic uncertainties of the hadron parameters obtained within this method. We start with examples from quantum mechanics, where bound-state properties may be calculated independently in two ways: exactly, by solving the Schroedinger equation, and approximately, by the method of sum rules. Knowing the exact solution allows us to control each step of the sum-rule extraction procedure. On the basis of this analysis, we formulate several improvements of the method of sum rules. We then apply these modifications to the analysis of the decay constants of heavy mesons.
Bound-state properties from field-theory correlators
International Nuclear Information System (INIS)
We discuss the details of calculating hadron properties from the OPE for correlators of quark currents in QCD, which constitutes the basis of the method of QCD sum rules. The main emphasis is laid on gaining control over the systematic uncertainties of the hadron parameters obtained within this method. We start with examples from quantum mechanics, where bound-state properties may be calculated independently in two ways: exactly, by solving the Schroedinger equation, and approximately, by the method of sum rules. Knowing the exact solution allows us to control each step of the sum-rule extraction procedure. On the basis of this analysis, we formulate several improvements of the method of sum rules. We then apply these modifications to the analysis of the decay constants of heavy mesons.
Baryons as relativistic three-quark bound states
Eichmann, Gernot; Williams, Richard; Alkofer, Reinhard; Fischer, Christian S
2016-01-01
We review the spectrum and electromagnetic properties of baryons described as relativistic three-quark bound states within QCD. The composite nature of baryons results in a rich excitation spectrum, whilst leading to highly non-trivial structural properties explored by the coupling to external (electromagnetic and other) currents. Both present many unsolved problems despite decades of experimental and theoretical research. We discuss the progress in these fields from a theoretical perspective, focusing on nonperturbative QCD as encoded in the functional approach via Dyson-Schwinger and Bethe-Salpeter equations. We give a systematic overview as to how results are obtained in this framework and explain technical connections to lattice QCD. We also discuss the mutual relations to the quark model, which still serves as a reference to distinguish 'expected' from 'unexpected' physics. We confront recent results on the spectrum of non-strange and strange baryons, their form factors and the issues of two-photon proce...
The structure of the D0-D4 bound state
International Nuclear Information System (INIS)
We derive a set of equations for the wavefunction describing the marginal bound state of a single D0-brane with a single D4-brane. These are equations determining the vacuum of an N=8 Abelian gauge theory with a charged hypermultiplet. We then solve these equations for the most general possible zero-energy solution using a Taylor series. We find that there are an infinite number of such solutions of which only one must be normalizable. We explore the structure of a normalizable solution under the assumption of an asymptotic expansion. Even the leading terms in the asymptotic series, which should reflect the supergravity solution, are unusual. Through the Spin(5) flavor symmetry, the modes which are massive at long distance actually influence the leading behavior. Lastly, we show that the vacuum equations can quite remarkably be reduced to a single equation involving one unknown function. The resulting equation has a surprisingly simple and suggestive form
Cooperativity, partially bound states, and enthalpy-entropy compensation.
Hunter, Christopher A; Tomas, Salvador
2003-11-01
Efforts to develop a quantitative understanding of molecular recognition rely on the additivity of individual intermolecular interactions, and cooperativity represents one of the major potential stumbling blocks. A chemical double-mutant cycle has been used to experimentally measure cooperativity between functional group interactions within a complex framework. The interaction between two aromatic groups varies by 0.2 +/- 0.4 kJ mol(-1) in synthetic H-bonded complexes that differ by 8-13 kJ mol(-1) in overall stability. In these systems, the free energies associated with individual intermolecular interactions can therefore be reliably treated in an additive fashion. The results suggest that alternative explanations should be considered for cooperative phenomena observed in other systems, and a rationale based on the population of partially bound states in flexible molecules is proposed to account for the enthalpic chelate effect and enthalpy-entropy compensation. PMID:14652069
Bound states in the continuum in open acoustic resonators
Lyapina, A A; Pilipchuk, A S; Sadreev, A F
2015-01-01
We consider bound states in the continuum (BSC) or embedded trapped modes in two- and three-dimensional acoustic axisymmetric duct-cavity structures. We demonstrate numerically that under variation of the length of the cavity multiple BSCs occur due to the Friedrich-Wintgen two-mode full destructive interference mechanism. The BSCs are detected by tracing the resonant widths to the points of the collapse of Fano resonances where one of the two resonant modes acquires infinite life-time. It is shown that the approach of the acoustic coupled mode theory cast in the truncated form of a two-mode approximation allows us to analytically predict the BSC frequencies and shape functions to a good accuracy in both two and three dimensions.
Rapid thermal co-annihilation through bound states
Kim, Seyong
2016-01-01
The co-annihilation rate of heavy particles close to thermal equilibrium, which plays a role in many classic dark matter scenarios, can be "simulated" in QCD by considering the pair annihilation rate of a heavy quark and antiquark at a temperature of a few hundred MeV. We show that the so-called Sommerfeld factors, parameterizing the rate, can be defined and measured non-perturbatively within the NRQCD framework. Lattice measurements indicate a modest suppression in the octet channel, in reasonable agreement with perturbation theory, and a large enhancement in the singlet channel, much above the perturbative prediction. We suggest that the additional enhancement originates from bound state formation and subsequent decay, omitted in previous estimates of thermal Sommerfeld factors, which were based on Boltzmann equations governing single-particle phase space distributions.
Tetra quark bound states in a Bethe-Salpeter approach
International Nuclear Information System (INIS)
We determine the mass of tetraquark bound states from a coupled system of covariant Bethe-Salpeter equations. Similar in spirit to the quark-diquark model of the nucleon, we approximate the full four-body equation for the tetraquark by a coupled set of two-body equations with meson and diquark constituents. These are calculated from their quark and gluon substructure using a phenomenologically well-established quark-gluon interaction. For the lightest scalar tetraquark we find a mass of the order of 400 MeV and a wave function dominated by the pion-pion constituents. Both results are in agreement with a meson molecule picture for the f0(600). Our results furthermore suggest the presence of a potentially narrow all-charm tetraquark in the mass region 5-6 GeV.
Delgado Tellez, Laura; Valdés, Álvaro; Prosmiti, Rita; Villarreal, Pablo; Delgado Barrio, Gerardo
2011-01-01
A theoretical study of the potential energy surface and bound states is performed for the ground state of the NeI2 van der Waals (vdW) complex. The three-dimensional interaction energies are obtained from ab initio coupled-cluster, coupled-cluster single double (triple)/complete basis set, calculations using large basis sets, of quadruple- through quintuple-zeta quality, in conjunction with relativistic effective core potentials for the heavy iodine atoms. For the analytical representation of...
Probing the Dark Sector with Dark Matter Bound States
An, Haipeng; Echenard, Bertrand; Pospelov, Maxim; Zhang, Yue
2016-04-01
A model of the dark sector where O (few GeV ) mass dark matter particles χ couple to a lighter dark force mediator V , mV≪mχ, is motivated by the recently discovered mismatch between simulated and observed shapes of galactic halos. Such models, in general, provide a challenge for direct detection efforts and collider searches. We show that for a large range of coupling constants and masses, the production and decay of the bound states of χ , such as 0-+ and 1-- states, ηD and ϒD, is an important search channel. We show that e+e-→ηD+V or ϒD+γ production at B factories for αD>0.1 is sufficiently strong to result in multiple pairs of charged leptons and pions via ηD→2 V →2 (l+l-) and ϒD→3 V →3 (l+l-) (l =e ,μ ,π ). The absence of such final states in the existing searches performed at BABAR and Belle sets new constraints on the parameter space of the model. We also show that a search for multiple bremsstrahlung of dark force mediators, e+e-→χ χ ¯+n V , resulting in missing energy and multiple leptons, will further improve the sensitivity to self-interacting dark matter.
Probing the Dark Sector with Dark Matter Bound States.
An, Haipeng; Echenard, Bertrand; Pospelov, Maxim; Zhang, Yue
2016-04-15
A model of the dark sector where O(few GeV) mass dark matter particles χ couple to a lighter dark force mediator V, m_{V}≪m_{χ}, is motivated by the recently discovered mismatch between simulated and observed shapes of galactic halos. Such models, in general, provide a challenge for direct detection efforts and collider searches. We show that for a large range of coupling constants and masses, the production and decay of the bound states of χ, such as 0^{-+} and 1^{--} states, η_{D} and ϒ_{D}, is an important search channel. We show that e^{+}e^{-}→η_{D}+V or ϒ_{D}+γ production at B factories for α_{D}>0.1 is sufficiently strong to result in multiple pairs of charged leptons and pions via η_{D}→2V→2(l^{+}l^{-}) and ϒ_{D}→3V→3(l^{+}l^{-}) (l=e,μ,π). The absence of such final states in the existing searches performed at BABAR and Belle sets new constraints on the parameter space of the model. We also show that a search for multiple bremsstrahlung of dark force mediators, e^{+}e^{-}→χχ[over ¯]+nV, resulting in missing energy and multiple leptons, will further improve the sensitivity to self-interacting dark matter. PMID:27127956
Bound states of the hydrogen atom in parabolic coordinates
G.F. Torres del Castillo; E. Navarro Morales
2008-01-01
Se obtiene el espectro y las eigenfunciones separables en coordenadas parabólicas para los estados ligados del átomo de hidrógeno, así como su relación con las eigenfunciones separables en coordenadas esféricas, haciendo uso de la teoría elemental del momento angular.
Two-vibron bound states in the β-Fermi-Pasta-Ulam model
Institute of Scientific and Technical Information of China (English)
Hu Xin-Guang; Tang Yi
2008-01-01
This paper studies the two-vibron bound states in the β-Fermi-Pasta-Ulam model by means of the number conserving approximation combined with the number state method.The results indicate that on-site,adjacent-site and mixed two-vibron bound states may exist in the model.Specially,wave number has a significant effect on such bound states,which may be considered as the quantum effects of the localized states in quantum systems.
Strongly bound metastable states of B2 + 2
Bruna, Pablo J.; Wright, James S.
1990-08-01
The stabilities of about 25 electronic states of B2+2 have been investigated using a multireference CI (MRD-CI) method and an AO basis set composed of 6s4p2d contracted Gaussian species per atom, including semidiffuse functions relevant for an adequate description of charge transfer interactions. The ground state X1∑+g (σ2gσ2u) is repulsive, as expected by its electronic configuration with a zero bond order. In spite of this and the doubly-positive charge, many excited states are found to be metastable, four of them (11∏g, 11∏u, 13∑-g, and 11Δg ) having potential wells from 1.52 eV (11∏u) to 2.83 eV (13∑-g). Relative to the ground state configuration, the metastable states arise from the excitations σu→σg(3∑+u), σu→πu(3,1∏g), σ2u→σgπu(3,1∏u), and σ2u→π2u(3∑-g, 1Δg, 1∑+g); they are analogous to those states showing deep local minima in B2 and B+2. Differences in stabilities among quasibound states can be explained on the basis of the asymptotic ΔE's between repulsive channels B++B+ and appropriate higher-lying limits (states) B+B2+ of bonding character; another important factor governing stability is the actual bonding character of the electronic configurations assigned to each state. The vertical double-ionization potential B2→B2+2(π2u→∞) between both ground states is 27.97 eV, the repulsive X1∑+g dication state being created with 8.37 eV excess energy relative to B++B+. Doubly-ionized states with a chance of being detected because of their long lifetimes against predissociation are those showing a strongly quasibound character, such as (with the vertical double ionization potential in eV given in parentheses): 11∏g(σuπu→∞; 30.29); 11∏u(σ2uπu→σg∞; 31.30); 13∑-g(σ2u→∞; 31.33), and 11Δg(σ2u→∞; 31.95).
Quantum phase transition triggering magnetic bound states in the continuum in graphene
Guessi, L. H.; Marques, Y.; Machado, R. S.; Kristinsson, K.; Ricco, L. S.; Shelykh, I. A.; Figueira, M. S.; de Souza, M.; Seridonio, A. C.
2015-12-01
Graphene hosting a pair of collinear adatoms in the phantom atom configuration has density of states vanishing in the vicinity of the Dirac point which can be described in terms of the pseudogap scaling as cube of the energy, Δ ∝|ɛ| 3 , which leads to the appearance of spin-degenerate bound states in the continuum (BICs) [Phys. Rev. B 92, 045409 (2015), 10.1103/PhysRevB.92.045409]. In the case when adatoms are locally coupled to a single carbon atom the pseudogap scales linearly with energy, which prevents the formation of BICs. Here, we explore the effects of nonlocal coupling characterized by the Fano factor of interference q0, tunable by changing the slope of the Dirac cones in the graphene band structure. We demonstrate that three distinct regimes can be identified: (i) for q0qc 2 the cubic scaling of the pseudogap with energy Δ ∝|ɛ| 3 characteristic to the phantom atom configuration is restored and the phase with nonmagnetic BICs is recovered. The phase with magnetic BICs can be described in terms of an effective intrinsic exchange field of ferromagnetic nature between the adatoms mediated by graphene monolayer. We thus propose a new type of QPT resulting from the competition between two ground states, respectively characterized by spin-degenerate and magnetic BICs.
Three-nucleon problem: trinucleon bound states and trinucleon interactions
International Nuclear Information System (INIS)
The assumptions underlying the formulation and solution of the Schroedinger equation for three nucleons in configuration space are reviewed, in conjunction with those qualitative aspects of the two-nucleon problem which are important. The geometrical features of the problem and the crucial role of the angular momentum barrier are developed. The boundary conditions for scattering are discussed qualitatively, and the Faddeev-Noyes equation is motivated. The method of splines and orthogonal collocation are shown to provide convenient techniques for generating numerical solutions. Properties of the many numerical solutions for the bound states and zero-energy scattering states are discussed. The evidence for three-body forces is reviewed, and the results of the recent calculations including such forces are discussed. The importance of electromagnetic interactions in the three-nucleon systems is motivated. Relativistic corrections and meson-exchange currents are discussed in the context of ''rules of scale'', and the pion-exchange currents of nonrelativistic order are derived. The experimental results for trinucleon electromagnetic interactions are reviewed, including recent tritium data. Conclusions are presented. 56 refs., 23 figs
Atomic squeezed states on an atom-chip
International Nuclear Information System (INIS)
In this thesis, we describe the construction of an experiment, allowing to produce 87Rb Bose-Einstein condensates on an atom chip, and then split them in a double well potential. An accurate imaging system has been developed, in order to be able to measure the absolute value of the populations of the double well within a very low noise level, almost limited by the optical shot noise. We measure atom number statistics after splitting, and directly observe number squeezed states, down to -4.9 dB at low temperatures, compared to a classical gas, of independent particles. The dependence in temperature of fluctuations has been also studied. For a thermal gas, Poissonian fluctuations are given by the probability distribution of the macroscopic configurations with a given atom number difference. In the degenerate regime, the entropy effect which favors small number differences vanishes, leading to super-Poissonian fluctuations, to more than +3.8 dB close to transition temperature. At low temperatures, the interaction energy cost associated with number fluctuations exceeds the available thermal energy, leading to sub-Poissonian fluctuations. Those two behaviours have been theoretically explained, both with a simple analytical model and a numerical one. We also measured the evolution of the relative phase between the two clouds, and its collapse due to interactions, allowing us to claim that this splitter is a coherent one. (author)
Multichannel quantum defect theory of strontium bound Rydberg states
International Nuclear Information System (INIS)
Using the reactance matrix approach, we systematically develop new multichannel quantum defect theory (MQDT) models for the singlet and triplet S, P, D and F states of strontium below the first ionization limit, based on improved energy level measurements. The new models reveal additional insights into the character of doubly excited perturber states, and the improved energy level measurements for certain series allow fine structure to be resolved for those series’ perturbers. Comparison between the predictions of the new models and those of previous empirical and ab initio studies reveals good agreement with most series; however, some discrepancies are highlighted. Using the MQDT wave functions derived from our models we calculate other observables such as Landé gJ-factors and radiative lifetimes. The analysis reveals the impact of perturbers on the Rydberg state properties of divalent atoms, highlighting the importance of including two-electron effects in the calculations of these properties. The work enables future investigations of properties such as Stark maps and long-range interactions of Rydberg states of strontium. (paper)
Lower bound on concurrence for arbitrary-dimensional tripartite quantum states
Chen, Wei; Fei, Shao-Ming; Zheng, Zhu-Jun
2016-06-01
In this paper, we study the concurrence of arbitrary-dimensional tripartite quantum states. An explicit operational lower bound of concurrence is obtained in terms of the concurrence of substates. A given example shows that our lower bound may improve the well-known existing lower bounds of concurrence. The significance of our result is to get a lower bound when we study the concurrence of arbitrary m⊗ n⊗ l -dimensional tripartite quantum states.
Teleportation of Unknown Atomic Entangled States Using GHZ Class States
International Nuclear Information System (INIS)
We propose two physical schemes, which can teleport unknown atomic entangled states from user A (Alice) to user B (Bob) via GHZ class states as quantum channel. The two schemes are both based on cavity QED techniques. In the two schemes, teleportation and distillation procedures can be realized simultaneously. The second teleportation scheme is more advantageous than the first one.
Unitary Transformations in Quantum Field Theory and Bound States
Shebeko, A V
2001-01-01
Finding the eigenstates of the total Hamiltonian H or its diagonalization is the important problem of quantum physics. However, in relativistic quantum field theory (RQFT) its complete and exact solution is possible for a few simple models only. Unitary transformations (UT's) considered in this survey do not diagonalize H, but convert H into a form which enables us to find approximately some H eigenstates. During the last years there have appeared many papers devoted to physical applications of such UT's. Our aim is to present a systematic and self-sufficient exposition of the UT method. The two general kinds of UT's are pointed out, distinct variations of each kind being possible. We consider in detail the problem of finding the simplest H eigenstates for interacting mesons and nucleons using the so-called ``clothing'' UT and Okubo's UT. These UT's allow us to suggest definite approaches to the problem of two-particle (deuteron-like) bound states in RQFT. The approaches are shown to yield the same two-nucleo...
Bound States via Higgs Exchanging and Resonant Di-Higgs
Kang, Zhaofeng
2016-01-01
The standard model (SM)-like Higgs boson $h$ has spin zero and light mass around weak scale, so it has the potential to mediate a new and relatively strong force for the particle $\\phi$ in the new physics (NP) sector; then $\\phi$ may form bound state $B_h$ via exchanging $h$. This phenomena may arise in a wide context, for instance composite Higgs, supersymmetry (SUSY) and radiative neutrino (or more widely in the models with a strong Higgs portal for triggering classical scale symmetry breaking or strong first-order phase transition). For illustration we focus on two typical examples, the stop/sbottom sector and an inert Higgs doublet. Furthermore, we point out that $B_h$ must give rise to a clear resonant di-Higgs signature, which recently has been extensively searched for at the large hadron collider (LHC). Moreover, Higgs radiative decay such as to di-photon probably will be significantly modified provided that $\\phi$ is charged or/and colored.
Unified description of bound, resonant and scattering states
International Nuclear Information System (INIS)
Recently we have introduced a general method for calculating the discrete Hilbert-space basis representation of the Green's operators of those Hamiltonians which have infinite symmetric tridiagonal matrix forms. The elements of this matrix are used in the calculation of the Green's matrix in terms of a three-term recurrence relation and continued fractions. We specified our general approach to the case of the Coulomb problem and the Coulomb-Sturmian basis associated with it. As a further step, we can combine this new way of calculating the Coulomb-Green's matrix with a technique of solving integral equations in discrete Hilbert-space-basis representations. This provides us with a quantum mechanical approximation method which is rather general in the sense that it is equally applicable to solving bound-, resonant- and scattering-state problems with practically any potential of physical relevance. The method is especially suited to problems where Coulomb-like asymptotics have to be treated, but the formalism also contains the case of the free Green's operator as a special case. (author)
Absorption spectrum of the excitons bound on neutral boron atoms in cubic silicon carbide
International Nuclear Information System (INIS)
Absorption spectrum of the excitons strongly bound on neutral deep acceptors (boron) is observed for the first time in silicon carbide 3C-SiC:B cubic crystals. The exciton binding energy with EBex acceptor equals 227 meV. The spectrum consists of three absorption lines at photon energies 2.1508; 2.1585 and 2.189 eV and a series of high energy maxima. The spectrum structure is explained by splitting of coupled exciton states by hole-hole exchange interaction in the local acceptor field. It is shown that because of extremely high probability of Auger-processes the decay of excitons bound on neutral boron in 3C-SiC is a radiationless one
Detection of π-μ Coulomb bound states
International Nuclear Information System (INIS)
We have observed atoms consisting of a pion and a muon produced in the decay K/subL/ 0→ (πμ)/suba//subt//subo//subm/ν. This represents the first observations of an atom composed of two unstable particles and of an atomic decay of an elementary particle
Supersymmetry Approaches to the Bound States of the Generalized Woods-Saxon Potential
Fakhri, H.; Sadeghi, J.
Using the associated Jacobi differential equation, we obtain exactly bound states of the generalization of Woods-Saxon potential with the negative energy levels based on the analytic approach. According to the supersymmetry approaches in quantum mechanics, we show that these bound states by four pairs of the first-order differential operators, represent four types of the laddering equations. Two types of these supersymmetry structures, suggest the derivation of algebraic solutions by two different approaches for the bound states.
Normalization of the covariant three-body bound state vertex function
Adam, J; Savkli, C; Van Orden, J W; Gross, Franz; Savkli, Cetin
1997-01-01
The normalization condition for the relativistic three nucleon Bethe-Salpeter and Gross bound state vertex functions is derived, for the first time, directly from the three body wave equations. It is also shown that the relativistic normalization condition for the two body Gross bound state vertex function is identical to the requirement that the bound state charge be conserved, proving that charge is automatically conserved by this equation.
Near optimal bounds on quantum communication complexity of single-shot quantum state redistribution
Anshu, Anurag; Devabathini, Vamsi Krishna; Jain, Rahul
2014-01-01
We show near optimal bounds on the worst case quantum communication of single-shot entanglement-assisted one-way quantum communication protocols for the {\\em quantum state redistribution} task and for the sub-tasks {\\em quantum state splitting} and {\\em quantum state merging}. Our bounds are tighter than previously known best bounds for the latter two sub-tasks. A key technical tool that we use is a {\\em convex-split} lemma which may be of independent interest.
Free energy barrier for melittin reorientation from a membrane-bound state to a transmembrane state
Irudayam, Sheeba J.; Pobandt, Tobias; Berkowitz, Max L.
2013-01-01
An important step in a phospholipid membrane pore formation by melittin antimicrobial peptide is a reorientation of the peptide from a surface into a transmembrane conformation. In this work we perform umbrella sampling simulations to calculate the potential of mean force (PMF) for the reorientation of melittin from a surface-bound state to a transmembrane state and provide a molecular level insight into understanding peptide and lipid properties that influence the existence of the free energ...
Bound states and critical behavior of the Yukawa potential
Institute of Scientific and Technical Information of China (English)
LI; Yongyao
2006-01-01
[1]Yukawa,H.,On the interaction of elementary particles,Proc.Phys.Math Soc.Jap.,1935,17:48-57.[2]Sachs,R.,Goeppert-Mayer,M.,Calculations on a new neutron-proton interaction potential,Phys.Rev.,1938,53:991-993.[3]Harris,G.,Attractive two-body interactions in partially ionized plasmas,Phys.Rev.,1962,125:1131-1140.[4]Schey,H.,Schwartz,J.,Counting the bound states in short-range central potentials,Phys.Rev.B,1965,139:1428-1432.[5]Rogers,J.,Graboske,H.,Harwood,E.,Bound eigenstates of the static screened Coulomb poten-tial,Phys.Rev.A,1970,1:1577-1586.[6]McEnnan,J.,Kissel,L.,Pratt,R.,Analytic perturbation theory for screened Coulomb potentials:non-relativistic case,Phys.Rev.A,1976,13:532-559.[7]Gerry,C.,Estimates of the ground states of the Yukawa potential from the Bogoliubov inequality,J.Phys.A,1984,17:L313-L315.[8]Kr(o)ger,H.,Girard,R.,Dufour,G.,Direct calculation of the S matrix in coordinate space,Phys.Rev.C,1988,37:486-496.[9]Girard,R.,Kr(o)ger,H.,Labelle,P.et al.,Computation of a long time evolution in a Schr(o)dinger system,Phys.Rev.A,1988,37:3195-3200.[10]Garavelli,S.,Oliveira,F.,Analytical solution for a Yukawa-type potential,Phys.Rev.Lett.,1991,66:1310-1313.[11]Gomes,O.,Chacham,H.,Mohallem,J.,Variational calculations for the bound-unbound transition of the Yukawa potential,Phys.Rev.A,1994,50:228-231.[12]Yukalov,V.,Yukalova,E.,Oliveira,F.,Renormalization-group solutions for Yukawa potential,J.Phys.A,1998,31:4337-4348.[13]Brau,F.,Necessary and sufficient conditions for existence of bound states in a central potential,J.Phys.A,2003,36:9907-9913.[14]Bertini,L.,Mella,M.,Bressanini,D.et al.,Borromean binding in H-2 with Yukawa potential:a nonadiabatic quantum Monte Carlo study,Phys.Rev.A,2004,69:042504.[15]Dean,D.,Drummond,I.,Horgan,R.,Effective diffusion constant in a two-dimensional medium of charged point scatterers,J.Phys.A,2004,37:2039-2046.[16]De-Leo,S.,Rotelli,P.,Amplification of coupling for Yukawa potentials,Phys.Rev.D,2004,69:034006.[17]Khrapak
Efimov effect and higher bound states in a three particle system
International Nuclear Information System (INIS)
The J=0 bound states for a system of three identical spinless particles interacting in pairs through delta-shell potentials are studied. The Efimov states are identified, and their wave functions obtained. A new family of bound states, which occurs for higher values of the attractive coupling strength was found
Resonant quenching of Rydberg atomic states by highly polar molecules
Narits, A. A.; Mironchuk, E. S.; Lebedev, V. S.
2016-06-01
The results of theoretical studies of the resonant quenching and ion-pair formation processes induced by collisions of Rydberg atoms with highly polar molecules possessing small electron affinities are reported. We elaborate an approach for describing collisional dynamics of both processes and demonstrate the predominant role of resonant quenching channel of reaction for the destruction of Rydberg states by electron-attaching molecules. The approach is based on the solution of the coupled differential equations for the transition amplitudes between the ionic and Rydberg covalent terms of a quasimolecule formed during a collision of particles. It takes into account the possibility of the dipole-bound anion decay in the Coulomb field of the positive ionic core and generalizes previous models of charge-transfer processes involving Rydberg atoms to the cases, when the multistate Landau–Zener approaches become inapplicable. Our calculations for {{Rb}}({nl}) atom perturbed by {{{C}}}2{{{H}}}4{{SO}}3, {{CH}}2{CHCN}, {{CH}}3{{NO}}2, {{CH}}3{CN}, {{{C}}}3{{{H}}}2{{{O}}}3, and {{{C}}}3{{{H}}}4{{{O}}}3 molecules show that the curves representing the dependence of the resonant quenching cross sections on the principal quantum number n are bell-shaped with the positions of maxima being shifted towards lower values of n and the peak values, {σ }{max}({{q})}, several times higher than those for the ion-pair formation, {σ }{max}({{i})}. We obtain a simple power relation between the energy of electron affinity of a molecule and the position of maximum in n-dependence of the resonant quenching cross section. It can be used as an additional means for determining small binding energies of dipole-bound anions from the experimental data on resonant quenching of Rydberg states by highly polar molecules.
Models of atoms in plasmas based on common formalism for bound and free electrons
International Nuclear Information System (INIS)
Atom-in-plasma models: Thomas-Fermi (TF) and INFERNO, AJCI and VAAQP, that use the same formalism for all electrons are briefly described and analyzed from the point of view of their thermodynamic consistence. While the TF and VAAQP models may be derived from variational principle and respect the virial theorem, it appears that two earlier quantum extensions of the quasi-classical TF model, INFERNO and AJCI, are not fully variational. The problems of the two latter approaches are analyzed from the point of view of the VAAQP model. However all quantum models seem to give unrealistic description of atoms in plasma at low temperature and high plasma densities. These difficulties are connected with the Wigner-Seitz cavity approach to non-central ions that is present in all considered models. Comparison of some equation-of-state data from TF, INFERNO and VAAQP models are shown on a chosen example. We report also on the status of our research on the frequency-dependent linear-response theory of atoms in plasma. A new Ehrenfest-type sum rule, originally proposed in the quantum VAAQP model, was proven in the case of the response of the TF atom with the Bloch hydrodynamics (TFB) and checked by numerical example. The TFB case allows one to have a direct insight into the rather involved mathematics of the self-consistent linear response calculations in situations when both the central atom and its plasma vicinity are perturbed by an electric field. (authors)
Models of atoms in plasmas based on common formalism for bound and free electrons
Blenski, T.; Piron, R.; Caizergues, C.; Cichocki, B.
2013-12-01
Atom-in-plasma models: Thomas-Fermi (TF) and INFERNO, AJCI and VAAQP, that use the same formalism for all electrons are briefly described and analyzed from the point of view of their thermodynamic consistence. While the TF and VAAQP models may be derived from variational principle and respect the virial theorem, it appears that two earlier quantum extensions of the quasi-classical TF model, INFERNO and AJCI, are not fully variational. The problems of the two latter approaches are analyzed from the point of view of the VAAQP model. However all quantum models seem to give unrealistic description of atoms in plasma at low temperature and high plasma densities. These difficulties are connected with the Wigner-Seitz cavity approach to non-central ions that is present in all considered models. Comparison of some equation-of-state data from TF, INFERNO and VAAQP models are shown on a chosen example. We report also on the status of our research on the frequency-dependent linear-response theory of atoms in plasma. A new Ehrenfest-type sum rule, originally proposed in the quantum VAAQP model, was proven in the case of the response of the TF atom with the Bloch hydrodynamics (TFB) and checked by numerical example. The TFB case allows one to have a direct insight into the rather involved mathematics of the self-consistent linear response calculations in situations when both the central atom and its plasma vicinity are perturbed by an electric field.
Probabilistic Teleportation of Three-Atom State via Five-Atom Cluster State
International Nuclear Information System (INIS)
A scheme for probabilistic teleportation of an unknown three-atom entangled state via a five-atom non-maximally entangled cluster state as quantum channel is proposed. In this scheme, the sender performs two Bell state and a single-atom measurements on the atoms, the receiver can reconstruct the original state with a certain probability by introducing an auxiliary atom and operating appropriate unitary transformations and controlled-not (C-not) operations according to the sender Alice's measurement results. As a result, the probability of successful teleportation is determined by the smallest two of the coefficients' absolute values of the cluster state. The considerable advantage of our scheme is that we employ a non-maximally entangled cluster state as quantum channel in the scheme, which can greatly reduce the amount of entanglement resources and need less classical bits. If we employ a maximally entangled cluster state as quantum channel, the probabilistic teleportation scheme becomes usual teleportation, the successful probability being 100%. (general)
Teleportation of Atomic States via Cavity Quantum Electrodynamics
Guerra, E S
2004-01-01
In this article we discuss a scheme of teleportation of atomic states. The experimental realization proposed makes use of cavity Quatum Electrodynamics involving the interaction of Rydberg atoms with a micromaser cavity prepared in a coherent state. We start presenting a scheme to prepare atomic Bell states via the interaction of atoms with a cavity. In our scheme the cavity and some atoms play the role of auxiliary systems used to achieve the teleportation.
Continuum bound states as surface states of a finite periodic system
International Nuclear Information System (INIS)
We discuss the relation between continuum bound states (CBSs) localized on a defect, and surface states of a finite periodic system. We model an experiment of Capasso et al. [F. Capasso, C. Sirtori, J. Faist, D. L. Sivco, S-N. G. Chu, and A. Y. Cho, Nature (London) 358, 565 (1992)] using the transfer-matrix method. We compute the rate for intrasubband transitions from the ground state to the CBS and derive a sum rule. Finally we show how to improve the confinement of a CBS while keeping the energy fixed
Quantum Chernoff bound as a measure of efficiency of quantum cloning for mixed states
Ghiu, Iulia
2014-01-01
In this paper we investigate the efficiency of quantum cloning of $N$ identical mixed qubits. We employ a recently introduced measure of distinguishability of quantum states called quantum Chernoff bound. We evaluate the quantum Chernoff bound between the output clones generated by the cloning machine and the initial mixed qubit state. Our analysis is illustrated by performing numerical calculation of the quantum Chernoff bound for different scenarios that involves the number of initial qubit...
A simple model for atomic layer doped field-effect transistor (ALD-FET) electronic states
Energy Technology Data Exchange (ETDEWEB)
Mora R, M.E. [Centro de Investigaciones en Optica, Unidad Aguascalientes. Juan de Montoro 207, Zona Centro, 20000 Aguascalientes (Mexico); Gaggero S, L.M. [Escuela de Fisica, Universidad Autonoma de Zacatecas, Av. Preparatoria 301, 98060 Zacatecas (Mexico)
1998-12-31
We propose a simple potential model based on the Thomas-Fermi approximation to reproduce the main properties of the electronic structure of an atomic layer doped field effect transistor. Preliminary numerical results for a Si-based ALD-FET justify why bound electronic states are not observed in the experiment. (Author)
Scattering and Bound State Solutions of the Yukawa Potential within the Dirac Equation
International Nuclear Information System (INIS)
In the presence of spin symmetry case, we obtain bound and scattering states solutions of the Dirac equation for the equal scalar and vector Yukawa potentials for any spin-orbit quantum number κ. The approximate analytical solutions are presented for the bound and scattering states and scattering phase shifts
Solitons in superfluid (He-3)-A - Bound states on domain walls
Ho, T. L.; Fulco, J. R.; Schrieffer, J. R.; Wilczek, F.
1984-01-01
The effects of solitons on the spectrum of fermion excitations in superfluid (He-3)-A are investigated. It is found that there is a two-dimensional manifold of bound states with energies within the gap of the bulk superfluid. The bound-state spectrum lacks inversion symmetry parallel to the wall.
The $DKP$ equation in the Woods-Saxon potential well: Bound states
Boutabia-Chéraitia, Boutheina
2016-01-01
We solve the Duffin-Kemmer-P\\'{e}tiau equation in the presence of a spatially one-dimensional symmetric potential well. We compute the scattering state solutions and we derive conditions for transmission resonances. The bound solutions are derived by a graphic study and the appearance of the antiparticle bound state is discussed.
Ensemble-based characterization of unbound and bound states on protein energy landscape
Ruvinsky, Anatoly M; Tuzikov, Alexander V; Vakser, Ilya A
2012-01-01
Characterization of protein energy landscape and conformational ensembles is important for understanding mechanisms of protein folding and function. We studied ensembles of bound and unbound conformations of six proteins to explore their binding mechanisms and characterize the energy landscapes in implicit solvent. First, results show that bound and unbound spectra often significantly overlap. Moreover, the larger the overlap the smaller the RMSD between bound and unbound conformational ensembles. Second, the analysis of the unbound-to-bound changes points to conformational selection as the binding mechanism for four of the proteins. Third, the center of the unbound spectrum has a higher energy than the center of the corresponding bound spectrum of the dimeric and multimeric states for most of the proteins. This suggests that the unbound states often have larger entropy than the bound states considered outside of the complex. Fourth, the exhaustively long minimization, making small intra-rotamer adjustments, ...
Bounds on the Capacity of the Relay Channel with Noncausal State Information at Source
Zaidi, Abdellatif; Piantanida, Pablo; Vandendorpe, Luc
2010-01-01
We consider a three-terminal state-dependent relay channel with the channel state available non-causally at only the source. Such a model may be of interest for node cooperation in the framework of cognition, i.e., collaborative signal transmission involving cognitive and non-cognitive radios. We study the capacity of this communication model. One principal problem in this setup is caused by the relay's not knowing the channel state. In the discrete memoryless (DM) case, we establish lower bounds on channel capacity. For the Gaussian case, we derive lower and upper bounds on the channel capacity. The upper bound is strictly better than the cut-set upper bound. We show that one of the developed lower bounds comes close to the upper bound, asymptotically, for certain ranges of rates.
Bound entangled states with a private key and their classical counterpart.
Ozols, Maris; Smith, Graeme; Smolin, John A
2014-03-21
Entanglement is a fundamental resource for quantum information processing. In its pure form, it allows quantum teleportation and sharing classical secrets. Realistic quantum states are noisy and their usefulness is only partially understood. Bound-entangled states are central to this question--they have no distillable entanglement, yet sometimes still have a private classical key. We present a construction of bound-entangled states with a private key based on classical probability distributions. From this emerge states possessing a new classical analogue of bound entanglement, distinct from the long-sought bound information. We also find states of smaller dimensions and higher key rates than previously known. Our construction has implications for classical cryptography: we show that existing protocols are insufficient for extracting private key from our distributions due to their "bound-entangled" nature. We propose a simple extension of existing protocols that can extract a key from them. PMID:24702340
The effect of η-η' mixing in the bound state version of the Skyrme model
International Nuclear Information System (INIS)
The η-η' mixing is incorporated in the symmetry breaking term in the extended Skyrme model Lagrangian. Besides η-soliton bound states, an s-wave and a p-wave η'-soliton bound states are found. After fixing the value of the strength parameter X of the ''alternative term'' to fit the s-wave η'-soliton bound state to the N(1535) negative-parity nucleon resonance, the η-soliton bound states disappear. Then only η'-soliton bound states are identified with nucleon resonances (I=1/2) and delta resonances (I=3/2). The predicted resonance masses agree well with experimental values. The decay widths ΓN*→N+η of the relevant nucleon resonances are also calculated to explain why these particles have large branching ratios in the ηN channel. (orig.)
Dynamics of F/D networks: the role of bound states
International Nuclear Information System (INIS)
In a field theory model, we study, via numerical experiments, the role of bound states in the evolution of cosmic superstring networks, being composed by p F strings, q D strings and (p,q) bound states. We find robust evidence for scaling of all three components of the network, independently of initial conditions. The novelty of our numerical approach consists of having control over the initial abundance of bound states. This indeed allows us to identify the effect of bound states on the evolution of the network. We also find an additional energy loss mechanism, resulting in a lower overall string network energy, and thus scaling of the network. This new mechanism consists of the formation of bound states with an increasing length
Interacting quantum walkers: two-body bosonic and fermionic bound states
Krapivsky, P. L.; Luck, J. M.; Mallick, K.
2015-11-01
We investigate the dynamics of bound states of two interacting particles, either bosons or fermions, performing a continuous-time quantum walk on a one-dimensional lattice. We consider the situation where the distance between both particles has a hard bound, and the richer situation where the particles are bound by a smooth confining potential. The main emphasis is on the velocity characterizing the ballistic spreading of these bound states, and on the structure of the asymptotic distribution profile of their center-of-mass coordinate. The latter profile generically exhibits many internal fronts.
Quasi-bound states, resonance tunnelling, and tunnelling times generated by twin symmetric barriers
Indian Academy of Sciences (India)
A Uma Maheswari; P Prema; S Mahadevan; C S Shastry
2009-12-01
In analogy with the definition of resonant or quasi-bound states used in three-dimensional quantal scattering, we define the quasi-bound states that occur in one-dimensional transmission generated by twin symmetric potential barriers and evaluate their energies and widths using two typical examples: (i) twin rectangular barrier and (ii) twin Gaussian-type barrier. The energies at which reflectionless transmission occurs correspond to these states and the widths of the transmission peaks are also the same as those of quasi-bound states. We compare the behaviour of the magnitude of wave functions of quasi-bound states with those for bound states and with the above-barrier state wave function. We deduce a Breit–Wigner-type resonance formula which neatly describes the variation of transmission coefficient as a function of energy at below-barrier energies. Similar formula with additional empirical term explains approximately the peaks of transmission coefficients at above-barrier energies as well. Further, we study the variation of tunnelling time as a function of energy and compare the same with transmission, reflection time and Breit–Wigner delay time around a quasi-bound state energy. We also find that tunnelling time is of the same order of magnitude as lifetime of the quasi-bound state, but somewhat larger.
Wallace, Rodrick
2015-08-01
The stabilization of human cognition via feedback from embedding social and cultural contexts is a dynamic process deeply intertwined with it, constituting, in a sense, the riverbanks directing the flow of a stream of generalized consciousness at different scales: Cultural norms and social interaction are synergistic with individual and group cognition and their disorders. A canonical failure mode in atomistic cultures is found to be a 'ground state' collapse well represented by atomistic models of economic interaction that are increasingly characterized as divorced from reality by heterodox economists. That is, high rates of psychopathic and antisocial personality disorder and obsessive compulsive disorder emerge as culture-bound syndromes particular to Western or Westernizing societies, or to those undergoing social disintegration. PMID:26003470
International Nuclear Information System (INIS)
The uniform method of numerical investigation of bound states and scattering processes 2→ 2 (including resonance states) in the Coulomb three-body (CTB) systems is developed. It is based on the adiabatic hyperspherical approach (AHSA) and includes the numerical realization and applications to the three-body mesic atomic systems. The results of calculations of bound states of these systems (including the local characteristics of the wave functions) and the scattering processes 2→ 2 (including the characteristics of the resonance states) are presented
Preparation of two and four-atom entangled states
Institute of Scientific and Technical Information of China (English)
无
2000-01-01
A scheme for preparing two and four-atom entangled states is presented. It is based on atom-cavity-field interactions. Firatly, the cav ity is prepared in the superposition of the number states through the atom under going a two-photon transition, the secondly, the two or four identical two-lev el atoms, which are all initially in their ground states, are sent through the c avity sequentially and can make resonant single-photon transition in the cavity . Then atomic entangled states are created and the cavity is left in the vacuum state.
Atomic states and properties of Pt-electrocatalyst
Institute of Scientific and Technical Information of China (English)
PENG; Hongjian
2006-01-01
Using the one-atom theory (OA), the atomic state of Pt-electrocatalyst with fcc structure was determined as follows: [Xe] (5dn)6.48 (5dc)2.02 (6Sc)1.48(6sf)0.02. The atomic states of this metal with hcp and bcc structures of primary characteristic crystals and liquid state was also studied. According to its atomic states, the relationship between the atomic states and crystalline structure, catalytic performance and conductivity was explained qualitatively. The potential curve, the temperature dependence of bulk modulus and linear thermal expansion coefficient of fcc-Pt were calculated quantitatively.
Realization of atomic GHZ states via cavity QED
International Nuclear Information System (INIS)
In this work we propose a scheme in which it is possible to generate atomic GHZ states by letting three-level atoms in a lambda configuration to interact with a cavity field followed by a displacement of the cavity field and a selective measurements on two-level atoms which disentangle the atoms and field states. We also propose a GHZ test based on such states. (author)
Versatile mode-locked fiber laser with switchable operation states of bound solitons.
Zou, Xin; Qiu, Jifang; Wang, Xiaodong; Ye, Zi; Shi, Jindan; Wu, Jian
2016-06-01
Bound states of two solitons are among the typical forms of bound states and can be observed in various operation states of mode-locked fiber lasers. We experimentally investigated bound solitons (BSs) in a passively mode-locked erbium-doped fiber laser based on a semiconductor saturable absorber mirror, whose operation states can be switched among multiple pulses, passively harmonic mode-locking, and "giant pulses" by simply adjusting the in-line polarization controller with the pump power fixed. Up to four pulses, fourth-order harmonic mode-locking (HML), and a "giant pulse" with four BSs were obtained with increasing pump power. Experimental results showed a correlative relationship among those operation states (N pulses/Nth-order HML/"giant pulses" of N bound solitons) at different pump power levels. The birefringence induced by the erbium-doped fiber inside the laser cavity played a vital role in the transitions of those operation states. PMID:27411182
Photon-assisted tunneling through a topological superconductor with Majorana bound states
Energy Technology Data Exchange (ETDEWEB)
Tang, Han-Zhao; Zhang, Ying-Tao, E-mail: zhangyt@mail.hebtu.edu.cn [College of Physics, Hebei Normal University, Shijiazhuang 050024 (China); Liu, Jian-Jun, E-mail: liujj@mail.hebtu.edu.cn [College of Physics, Hebei Normal University, Shijiazhuang 050024 (China); Department of Physics, Shijiazhuang University, Shijiazhuang 050035 (China)
2015-12-15
Employing the Keldysh Nonequilibrium Green’s function method, we investigate time-dependent transport through a topological superconductor with Majorana bound states in the presence of a high frequency microwave field. It is found that Majorana bound states driven by photon-assisted tunneling can absorb(emit) photons and the resulting photon-assisted tunneling side band peaks can split the Majorana bound state that then appears at non-zero bias. This splitting breaks from the current opinion that Majorana bound states appear only at zero bias and thus provides a new experimental method for detecting Majorana bound states in the Non-zero-energy mode. We not only demonstrate that the photon-assisted tunneling side band peaks are due to Non-zero-energy Majorana bound states, but also that the height of the photon-assisted tunneling side band peaks is related to the intensity of the microwave field. It is further shown that the time-varying conductance induced by the Majorana bound states shows negative values for a certain period of time, which corresponds to a manifestation of the phase coherent time-varying behavior in mesoscopic systems.
Photon-assisted tunneling through a topological superconductor with Majorana bound states
Directory of Open Access Journals (Sweden)
Han-Zhao Tang
2015-12-01
Full Text Available Employing the Keldysh Nonequilibrium Green’s function method, we investigate time-dependent transport through a topological superconductor with Majorana bound states in the presence of a high frequency microwave field. It is found that Majorana bound states driven by photon-assisted tunneling can absorb(emit photons and the resulting photon-assisted tunneling side band peaks can split the Majorana bound state that then appears at non-zero bias. This splitting breaks from the current opinion that Majorana bound states appear only at zero bias and thus provides a new experimental method for detecting Majorana bound states in the Non-zero-energy mode. We not only demonstrate that the photon-assisted tunneling side band peaks are due to Non-zero-energy Majorana bound states, but also that the height of the photon-assisted tunneling side band peaks is related to the intensity of the microwave field. It is further shown that the time-varying conductance induced by the Majorana bound states shows negative values for a certain period of time, which corresponds to a manifestation of the phase coherent time-varying behavior in mesoscopic systems.
Analytical bounds on SET charge sensitivity for qubit readout in a solid-state quantum computer
International Nuclear Information System (INIS)
Full text: Quantum Computing promises processing powers orders of magnitude beyond what is possible in conventional silicon-based computers. It harnesses the laws of quantum mechanics directly, exploiting the in built potential of a wave function for massively parallel information processing. Highly ordered and scaleable arrays of single donor atoms (quantum bits, or qubits), embedded in Si, are especially promising; they are a very natural fit to the existing, highly sophisticated, Si industry. The success of Si-based quantum computing depends on precisely initializing the quantum state of each qubit, and on precise reading out its final form. In the Kane architecture the qubit states are read out by detecting the spatial distribution of the donor's electron cloud using a sensitive electrometer. The single-electron transistor (SET) is an attractive candidate readout device for this, since the capacitive, or charging, energy of a SET's metallic central island is exquisitely sensitive to its electronic environment. Use of SETs as high-performance electrometers is therefore a key technology for data transfer in a solid-state quantum computer. We present an efficient analytical method to obtain bounds on the charge sensitivity of a single electron transistor (SET). Our classic Green-function analysis provides reliable estimates of SET sensitivity optimizing the design of the readout hardware. Typical calculations, and their physical meaning, are discussed. We compare them with the measured SET-response data
Atomic structure and electronic states of extended defects in silicon
International Nuclear Information System (INIS)
Defects in silicon like dislocations, grain boundaries, silicide precipitates, etc. are spatially extended and associated with a large number of electronic states in the band gap. Our knowledge on the relation between atomic structure and electronic states of these extended defects presently starts to grow by applying high-resolution electron microscopy (HRTEM) and deep level transient spectroscopy (DLTS) in combination with numerical simulations. While by means of HRTEM details of structure can be studied, DLTS has been shown to allow for a classification of extended defect states into bandlike and localized. Moreover, this method opens the perspective to distinguish between trap-like and recombination-like electrical activity. In this paper, we emphasize the particular role of nickel and copper silicide precipitates, since in their cases structural features could be successfully related to specific DLTS line characteristics. Rapid quenching from high diffusion temperatures prevents decoration of platelet-shaped NiSi2 and Cu3Si precipitates with other impurities. This allows to study their intrinsic electrical activity. Comparison of experimental results with numerical simulations enables identification of structural units originating electrical activity and yields first evaluations of extended defect parameters. Accordingly, e.g., in the case of as-quenched NiSi2 it is the dislocation bounding the platelet that provides a one-dimensional distribution of deep electronic states
Skyrmion model in 2+1 dimensions with soliton bound states
Energy Technology Data Exchange (ETDEWEB)
Piette, B.; Zakrzewski, W.J. (Dept. of Mathematical Sciences, Univ. Durham (United Kingdom))
1993-03-22
We consider a class of skyrmion models in 2+1 dimensions which possess bound stable solitons. We show that these models have one-soliton solutions as well as static solutions corresponding to their bound states. We study the scattering and stability properties of these solutions, compute their energies and estimate their binding energies. (orig.).
Bound states of fermions on 2D lattice in a dilute limit
International Nuclear Information System (INIS)
We examine extended bound states in a dilute limit of the extended Hubbard model on the two-dimensional square lattice. By solving exactly the two-body problem we have determined the binding energies, mobilities and dispersion curves across the Brillouin zone for bound states of various symmetries. It turns out that the d-wave pairing is strongly favoured by the nnn hopping and the intersite local pairs can have small effective masses, even on the case of strong binding.We have also found a possibility of extended s-dx2-y2 mixing of the bound states. (author)
Taming the Yukawa potential singularity: improved evaluation of bound states and resonance energies
Energy Technology Data Exchange (ETDEWEB)
Alhaidari, A D [Shura Council, Riyadh 11212 (Saudi Arabia); Bahlouli, H [Physics Department, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Abdelmonem, M S [Physics Department, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia)
2008-01-25
Using the tools of the J-matrix method, we absorb the 1/r singularity of the Yukawa potential in the reference Hamiltonian, which is handled analytically. The remaining part, which is bound and regular everywhere, is treated by an efficient numerical scheme in a suitable basis using the Gauss quadrature approximation. Analysis of resonance energies and bound states spectrum is performed using the complex scaling method, where we show their trajectories in the complex energy plane and construct a video showing how bound states cross over into resonance states by varying the potential parameters. (fast track communication)
Teleportation of Unknown Superpositions of Collective Atomic Coherent States
Institute of Scientific and Technical Information of China (English)
ZHENG ShiBiao
2001-01-01
We propose a scheme to teleport an unknown superposition of two atomic coherent states with different phases. Our scheme is based on resonant and dispersive atom-field interaction. Our scheme provides a possibility of teleporting macroscopic superposition states of many atoms first time.``
Light pulse analysis with a multi-state atom interferometer
Energy Technology Data Exchange (ETDEWEB)
Herrera, I.; Lombardi, P.; Schäfer, F. [European Laboratory for Nonlinear Spectroscopy (LENS), Via N. Carrara 1, 50019 Sesto F.no (Italy); Petrovic, J. [Vinca Institute of Nuclear Sciences, P. O. B. 522, 11001 Belgrade (Serbia); Cataliotti, F. S. [European Laboratory for Nonlinear Spectroscopy (LENS), Via N. Carrara 1, 50019 Sesto F.no (Italy); Dipartimento di Fisica e Astronomia, Universitá di Firenze, Via Sansone 3, 50019 Sesto F.no (Italy)
2014-12-04
We present a controllable multi-state cold-atom interferometer that is easy-to-use and fully merged on an atom chip. We demonstrate its applications as a sensor of the fields whose interactions with atoms are state-dependent.
Exploring the Single Atom Spin State by Electron Spectroscopy.
Lin, Yung-Chang; Teng, Po-Yuan; Chiu, Po-Wen; Suenaga, Kazu
2015-11-13
To control the spin state of an individual atom is an ultimate goal for spintronics. A single atom magnet, which may lead to a supercapacity memory device if realized, requires the high-spin state of an isolated individual atom. Here, we demonstrate the realization of well isolated transition metal (TM) atoms fixed at atomic defects sparsely dispersed in graphene. Core-level electron spectroscopy clearly reveals the high-spin state of the individual TM atoms at the divacancy or edge of the graphene layer. We also show for the first time that the spin state of single TM atoms systematically varies with the coordination of neighboring nitrogen or oxygen atoms. These structures can be thus regarded as the smallest components of spintronic devices with controlled magnetic behavior. PMID:26613462
Pair creation induced by transitions between electronic and positronic bound states
Liu, Y.; Lv, Q. Z.; Li, Y. T.; Grobe, R.; Su, Q.
2015-05-01
We study the creation process of electron-positron pairs from the quantum electrodynamical vacuum under very strong electric fields by solving the quantum field theoretical Dirac equation on a space-time grid. We investigate the role of bound-bound state mixing in such a process, which can be studied if the external force can be modeled by a combination of a potential barrier and a potential well. By increasing the magnitude of the two potentials, discrete states that originate from the positive and negative energy continua can become quasidegenerate in the mass gap region (between -mc 2 and mc 2). We show that this bound-bound state mixing is quite different from the usual bound-continuum state mixing where the particles are created until the Pauli exclusion principle inhibits this process. In the case of bound-bound mixing the particle number exhibits a characteristic oscillatory behavior that in principle can last forever. These findings can be modeled by an effective two-state model.
Generation and storage of quantum states using cold atoms
DEFF Research Database (Denmark)
Dantan, Aurelien Romain; Josse, Vincent; Cviklinski, Jean; Bramati, Alberto; Pinard, Michel; Giacobino, Elisabeth
Cold cesium or rubidium atomic samples have a good potential both for generation and storage of nonclassical states of light. Generation of nonclassical states of light is possible through the high non-linearity of cold atomic samples excited close to a resonance line. Quadrature squeezing, polar......, polarization squeezing and entanglement have been demonstrated. Quantum state storage is made possible by the presence of long-lived angular momentum in the ground state. Cold atoms are thus a promising resource in quantum information....
Preparation of Entangled Atomic States Through Resonant Atom-Field Interaction
Institute of Scientific and Technical Information of China (English)
无
2006-01-01
A scheme is proposed for the generation of two-atom maximally entangled states and multi-atom maximally entangled states of W class. The scheme is based on the simultaneous resonant interaction of atoms with a single-mode cavity field. It does not require accurate adjustment of the interaction time. The time needed to complete the generation does not increase with the number of the atom.
An Improved Lower Bound Limit State Optimisation Algorithm
DEFF Research Database (Denmark)
Frier, Christian; Damkilde, Lars
2010-01-01
Limit State analysis has been used in engineering practice for many years e.g. the yield-line method for concrete slabs and slip-line solutions in geotechnics. In the recent years there has been an increased interest in numerical Limit State analysis, and today algorithms take into account the non...
An Improved Lower Bound Limit State Optimisation Algorithm
DEFF Research Database (Denmark)
Frier, Christian; Damkilde, Lars
2010-01-01
Limit State analysis has been used in manual design methods for decades e.g. the yield line theory for concrete slabs.......Limit State analysis has been used in manual design methods for decades e.g. the yield line theory for concrete slabs....
Generation of Superposition Spin States in an Atomic Ensemble
Massar, S.; Polzik, E. S.
2003-01-01
A method for generating a mesoscopic superposition state of the collective spin variable of a gas of atoms is proposed. The state consists of a superposition of the atomic spins pointing in two slightly different directions. It is obtained by using off resonant light to carry out Quantum Non Demolition Measurements of the spins. The relevant experimental conditions, which require very dense atomic samples, can be realized with presently available techniques. Long-lived atomic superposition st...
Fano effect and Andreev bound states in T-shape double quantum dots
Energy Technology Data Exchange (ETDEWEB)
Calle, A.M.; Pacheco, M. [Departamento de Física, Universidad Técnica Federico Santa María, Casilla 110-V, Valparaíso (Chile); Orellana, P.A., E-mail: orellana@ucn.cl [Departamento de Física, Universidad Católica del Norte, Casilla 1280, Antofagasta (Chile)
2013-09-02
In this Letter, we investigate the transport through a T-shaped double quantum dot coupled to two normal metal leads left and right and a superconducting lead. Analytical expressions of Andreev transmission and local density of states of the system at zero temperature have been obtained. We study the role of the superconducting lead in the quantum interferometric features of the double quantum dot. We report for first time the Fano effect produced by Andreev bound states in a side quantum dot. Our results show that as a consequence of quantum interference and proximity effect, the transmission from normal to normal lead exhibits Fano resonances due to Andreev bound states. We find that this interference effect allows us to study the Andreev bound states in the changes in the conductance between two normal leads. - Highlights: • Transport properties of a double quantum dot coupled in T-shape configuration to conducting and superconducting leads are studied. • We report Fano antiresonances in the normal transmission due to the Andreev reflections in the superconducting lead. • We report for first time the Fano effect produced by Andreev bound states in a side quantum dot. • Fano effect allows us to study the Andreev bound states in the changes in the conductance between two normal leads. • Andreev bound states survives even for strong dot-superconductor coupling.
Fano effect and Andreev bound states in T-shape double quantum dots
International Nuclear Information System (INIS)
In this Letter, we investigate the transport through a T-shaped double quantum dot coupled to two normal metal leads left and right and a superconducting lead. Analytical expressions of Andreev transmission and local density of states of the system at zero temperature have been obtained. We study the role of the superconducting lead in the quantum interferometric features of the double quantum dot. We report for first time the Fano effect produced by Andreev bound states in a side quantum dot. Our results show that as a consequence of quantum interference and proximity effect, the transmission from normal to normal lead exhibits Fano resonances due to Andreev bound states. We find that this interference effect allows us to study the Andreev bound states in the changes in the conductance between two normal leads. - Highlights: • Transport properties of a double quantum dot coupled in T-shape configuration to conducting and superconducting leads are studied. • We report Fano antiresonances in the normal transmission due to the Andreev reflections in the superconducting lead. • We report for first time the Fano effect produced by Andreev bound states in a side quantum dot. • Fano effect allows us to study the Andreev bound states in the changes in the conductance between two normal leads. • Andreev bound states survives even for strong dot-superconductor coupling
The bound state Aharonov-Bohm effect around a cosmic string revisited
Filgueiras, C.; Moraes, Fernando
2005-01-01
In this article we observe that the self-adjoint extension of the Hamiltonian of a particle moving around a shielded cosmic string gives rise to a gravitational analogue of the bound state Aharonov-Bohm effect.
Sufficient conditions for the existence of a bound state in the N-body problem
International Nuclear Information System (INIS)
Simple sufficient conditions for the existence of a bound state in the system of N particles interacting via a purely attractive two-body potential are provided. This method is based on a variational approach. (Author)
The dynamical gluon mass in the massless bound-state formalism
Ibanez, David
2014-01-01
We describe the phenomenon of dynamical gluon mass generation within the massless bound-state formalism, which constitutes the general framework for the systematic implementation of the Schwinger mechanism in non-Abelian gauge theories. The main ingredient of this formalism is the dynamical formation of bound states with vanishing mass, which gives rise to effective vertices containing massless poles; these vertices, in turn, trigger the Schwinger mechanism, and allow for the gauge-invariant generation of an effective gluon mass. In this particular approach, the gluon mass is directly related to quantities that are intrinsic to the bound-state formation itself, such as the "transition amplitude" and the corresponding "bound-state wave-function". Specifically, a set of powerful relations discussed in the text, allows one to determine the dynamical evolution of the gluon mass through a Bethe-Salpeter equation, which controls the dynamics of the relevant wave-function. In addition, it is possible to demonstrate ...
Bound states in the dynamics of a dipole in the presence of a conical defect
De Ribeiro, C A L; Moraes, F; Furtado, Claudio; Moraes, Fernando
2005-01-01
In this work we investigate the quantum dynamics of an electric dipole in a $(2+1)$-dimensional conical spacetime. For specific conditions, the Schr\\"odinger equation is solved and bound states are found with the energy spectrum and eigenfunctions determined. We find that the bound states spectrum extends from minus infinity to zero with a point of accumulation at zero. This unphysical result is fixed when a finite radius for the defect is introduced.
Bound states in the two-dimension massive quantum electrodynamics (Qed2)
International Nuclear Information System (INIS)
This work studies the fermion-antifermion bound states in the (1+1)D two-dimension massive quantum electrodynamic in the 1/N expansion. The scattering matrices in the non-relativistic approximation have been calculated through TQC, and compared with the cross section in the Born approximation, and therefore the potential responsible by the interactions in the scattering processes have been obtained. Using Schroedinger equation, the existence of possible bound states have been investigated
Two-polariton bound states in the Jaynes-Cummings-Hubbard model
International Nuclear Information System (INIS)
We examine the eigenstates of the one-dimensional Jaynes-Cummings-Hubbard model in the two-excitation subspace. We discover that two-excitation bound states emerge when the ratio of vacuum Rabi frequency to the tunneling rate between cavities exceeds a critical value. We determine the critical value as a function of the quasimomentum quantum number, and indicate that the bound states carry a strong correlation in which the two polaritons appear to be spatially confined together.
Quantum Chernoff bound as a measure of the efficiency of quantum cloning for mixed states
International Nuclear Information System (INIS)
In this paper we investigate the efficiency of quantum cloning of N identical mixed qubits. We employ a recently introduced measure of distinguishability of quantum states called the quantum Chernoff bound. We evaluate the quantum Chernoff bound between the output clones generated by the cloning machine and the initial mixed qubit state. Our analysis is illustrated by performing numerical calculation of the quantum Chernoff bound for different scenarios that involves the number of initial qubits N and the number of output imperfect copies M. (paper)
QQqq Four-Quark Bound States in Chiral SU(3) Quark Model
Institute of Scientific and Technical Information of China (English)
ZHANG Ming; ZHANG Hai-Xia; ZHANG Zong-Ye
2008-01-01
The possibility of QQqq heavy-light four-quark bound states has been analyzed by means of the chiral SU(3) quark model, where Q is the heavy quark (c or b) and q is the light quark (u, d, or s). We obtain a bound state for the bbnn configuration with quantum number JP=1+, I=0 and for the ccnn (JP=1+, I=0) configuration, which is not bound but slightly above the D*D* threshold (n is u or d quark). Meanwhile, we also conclude that a weakly bound state in bbnn system can also be found without considering the chiral quark interactions between the two light quarks, yet its binding energy is weaker than that with the chiral quark interactions.
Quantum Teleportation of High-dimensional Atomic Momenta State
Qurban, Misbah; Abbas, Tasawar; Rameez-ul-Islam; Ikram, Manzoor
2016-06-01
Atomic momenta states of the neutral atoms are known to be decoherence resistant and therefore present a viable solution for most of the quantum information tasks including the quantum teleportation. We present a systematic protocol for the teleportation of high-dimensional quantized momenta atomic states to the field state inside the cavities by applying standard cavity QED techniques. The proposal can be executed under prevailing experimental scenario.
From the Deuteron to Deusons, an Analysis of Deuteronlike Meson-Meson Bound States
Törnqvist, N A
1994-01-01
A systematic study of possible deuteronlike two-meson bound states, {\\it deusons}, is presented. Previous arguments that many such bound states may exist are elaborated with detailed arguments and numerical calculations including, in particular, the tensor potential. In the heavy meson sector one-pion exchange alone is strong enough to form at least deuteron-like $B\\bar B^*$ and $B^*\\bar B^*$ composites bound by approximately 50 MeV. Composites of $D\\bar D^*$ and $D^*\\bar D^*$ states bound by pion exchange alone are expected near the thresholds, while in the light meson sector one generally needs some additional short range attraction to form bound states. The quantum numbers of these states are I=0, In $B\\bar B^*$ one predictss the states: $\\eta_b(\\approx 10545),\\ \\chi_{b1}(\\approx 10562)$, and in $B^*\\bar B^*$ one finds the states: $\\eta_b(\\approx 10590),\\ \\chi_{b0}(\\approx 10582),\\ h_b(\\approx 10608),\\ \\chi_{b2}(\\approx 10602)$. Near the $D\\bar D^*$ threshold the states: $\\eta_c(\\approx 3870),\\ \\chi_{c0}(\\...
Bound States for Hypercentral Singular and Exponential Potentials
Institute of Scientific and Technical Information of China (English)
无
2006-01-01
With a view to obtaining an exact closed form solution to the Schrodinger equation for a variety of hypercentral potentials, we investigate further application of an ansatz. This method is good enough for many kinds of potentials, but in this article it applies to a type of the hypercentral singular potentials V(x) = ax2 + bx-4 + cx-6 and exponential hypercentral Morse potential U(x) = U0 ( e-2ax -2 e-ax) for three interacting particles. The Morse potential is used for diatomic molecule while this method will be successfully used for many atomic molecules. The three-body potentials are more easily introduced and treated within the hyperspherical harmonic formalism. The internal particle motion is usually described by means of Jacobi relative coordinates ρ, λ, and R, in terms of three particle positions r1,r2, and r3. We discuss some results obtained by using harmonic and anharmonic oscillators, however the hypercentral potential can be easily generalized in order to allow a systematic analysis, which admits an exact solution of the wave equation. This method is also applied to some other types of three-body, four-body, ..., interacting potentials.
Bethe-Salpeter bound-state structure in Minkowski space
Gutierrez, C.; Gigante, V.; Frederico, T.; Salmè, G.; Viviani, M.; Tomio, Lauro
2016-08-01
The quantitative investigation of the scalar Bethe-Salpeter equation in Minkowski space, within the ladder-approximation framework, is extended to include the excited states. This study has been carried out for an interacting system composed by two massive bosons exchanging a massive scalar, by adopting (i) the Nakanishi integral representation of the Bethe-Salpeter amplitude, and (ii) the formally exact projection onto the null plane. Our analysis, on one hand, confirms the reliability of the method already applied to the ground state and, on the other one, extends the investigation from the valence distribution in momentum space to the corresponding quantity in the impact-parameter space, pointing out some relevant features, like (i) the equivalence between Minkowski and Euclidean transverse-momentum amplitudes, and (ii) the leading exponential fall-off of the valence wave function in the impact-parameter space.
Bethe-Salpeter bound-state structure in Minkowski space
Gutierrez, C; Frederico, T; Salmè, G; Viviani, M; Tomio, Lauro
2016-01-01
The quantitative investigation of the scalar Bethe-Salpeter equation in Minkowski space, within the ladder-approximation framework, is extended to include the excited states. This study has been carried out for an interacting system composed by two massive bosons exchanging a massive scalar, by adopting (i) the Nakanishi integral representation of the Bethe-Salpeter amplitude, and (ii) the formally exact projection onto the null plane. Our analysis, on one hand, confirms the reliability of the method already applied to the ground state and, on the other one, extends the investigation from the valence distribution in momentum space to the corresponding quantity in the impact-parameter space, pointing out some relevant features, like (i) the equivalence between Minkowski and Euclidean transverse-momentum amplitudes, and (ii) the leading exponential fall-off of the valence wave function in the impact-parameter space.
Is the exotic $X(5568)$ a bound state?
Chen, Xiaoyun
2016-01-01
Stimulated by the recent observation of the exotic $X(5568)$ state by D0 Collaboration, we study the four-quark system $us\\bar{b}\\bar{d}$ with quantum numbers $J^P=0^+$ in the framework of chiral quark model. Two structures, diquark-antidiquark and meson-meson, with all possible color configurations are investigated by using Gaussian expansion method. The results show that energies of the tetraquark states with diquark-antiquark structure are too high to the candidate of $X(5568)$, and no molecular structure can be formed in our calculations. The calculation is also extended to the four-quark system $us\\bar{c}\\bar{d}$ and the same results as that of $us\\bar{b}\\bar{d}$ are obtained.
Teleportation of an Unknown Atomic State via Adiabatic Passage
Institute of Scientific and Technical Information of China (English)
无
2007-01-01
We propose a scheme for teleporting an unknown atomic state via adiabatic passage. Taking advantage of adiabatic passage, the atom has no probability of being excited and thus the atomic spontaneous emission is suppressed.We also show that the fidelity can reach 1 under certain condition.
Atomic cluster and graph states. An engineering proposal
International Nuclear Information System (INIS)
We suggest a simple method to generate cluster states of two-level atoms. The protocol utilizes minimum cavity/atomic resources and is based upon standard cavity QED tools along with Ramsey technique. Two identical atoms, each initially prepared in coherent superposition, interact simultaneously with an initially vacuum state cavity for a specified time. One atom has resonant interactions while at the same time the other one interacts dispersively. When, after completion of the interaction, cavity is again left into vacuum then atoms are shown to be entangled in bipartite cluster state. The method is also generalized to generate multi-partite linear cluster states as well as the atomic graph states. (author)
$D^*$ $\\Xi N$ bound state in strange three-body systems
Garcilazo, H
2016-01-01
The recent update of the strangeness $-2$ ESC08c Nijmegen potential incorporating the NAGARA and KISO events predicts a $\\Xi N$ bound state, $D^*$, in the $^3S_1 (I=1)$ channel. We study if the existence of this two-body bound state could give rise to stable three-body systems. For this purpose we solve the bound state problem of three-body systems where the $\\Xi N$ state is merged with $N$'s, $\\Lambda$'s, $\\Sigma's$ or $\\Xi$'s, making use of the most recent updates of the two-body ESC08c Nijmegen potentials. We found that there appear stable states in the $\\Xi NN$ and $\\Xi \\Xi N$ systems, the $\\Xi \\Lambda N$ and $\\Xi \\Sigma N$ systems being unbound.
Precision Excited State Lifetime Measurements for Atomic Parity Violation and Atomic Clocks
Sell, Jerry; Patterson, Brian; Gearba, Alina; Snell, Jeremy; Knize, Randy
2016-05-01
Measurements of excited state atomic lifetimes provide a valuable test of atomic theory, allowing comparisons between experimental and theoretical transition dipole matrix elements. Such tests are important in Rb and Cs, where atomic parity violating experiments have been performed or proposed, and where atomic structure calculations are required to properly interpret the parity violating effect. In optical lattice clocks, precision lifetime measurements can aid in reducing the uncertainty of frequency shifts due to the surrounding blackbody radiation field. We will present our technique for precisely measuring excited state lifetimes which employs mode-locked ultrafast lasers interacting with two counter-propagating atomic beams. This method allows the timing in the experiment to be based on the inherent timing stability of mode-locked lasers, while counter-propagating atomic beams provides cancellation of systematic errors due to atomic motion to first order. Our current progress measuring Rb excited state lifetimes will be presented along with future planned measurements in Yb.
Photoionization spectra of even-parity states of Sm atom with multistep excitation
International Nuclear Information System (INIS)
Two-color stepwise excitation and photoionization schemes are adopted to study the spectra of bound even-parity high-lying states of the Sm atom with three different excitation paths via the 4f66s6p 7DJ (J=1, 2 and 3) intermediate states. In order to obtain the information of these high-lying states, the Sm atom in these high-lying states is photoionized with an extra photon. Among 231 states detected in the energy region between 35,545 and 44,225 cm-1, 108 states are newly discovered, while the rest can be identified as the same with the literature. In most cases, comparisons of the spectra corresponding to the three different excitation paths may partially determine the total angular momentum of the observed peaks with the selection rules. In addition, the relative intensities of all related transition lines are given.
Test of Nonlocality with an Atom-Field Entangled State
Institute of Scientific and Technical Information of China (English)
ZHENG Shi-Biao
2002-01-01
We propose a scheme for the test of nonlocality with atom-field entanglement. An atom is sent through a cavity filled with a coherent field with a small amplitude. The dispersive interaction leads to atom-field entanglement.Then the field is driven by a classical current. The Bell inequality can be tested by the joint measurement of the parity of the field and the atomic state.
Soliton Atom Laser with Quantum State Transfer Property
Institute of Scientific and Technical Information of China (English)
LIU Xiong-Jun; JING Hui; GE Mo-Lin
2006-01-01
@@ We study the nonlinear effects in the quantum states transfer technique from photons to matter waves in the three-level case, which may provide the formation of a soliton atom laser with nonclassical atoms. The validity of quantum transfer mechanism is confirmed in the presence of the intrinsic nonlinear atomic interactions. The accompanied frequency chirp effect is shown to have no influence on the grey solitons formed by the output atom laser and the possible quantum depletion effect is also briefly discussed.
Remote atomic information concentration without Bell-state measurement
Institute of Scientific and Technical Information of China (English)
Wu Zhen-Zhen; Fang Mao-Fa
2006-01-01
This paper proposes a scheme for information concentration of two remote two-level atoms in cavity QED. This scheme does not involve the Bell-state measurement. During the interaction between atom and cavity, the cavity frequency is large-detuned from the atomic transition frequency, thus the scheme is insensitive to both the cavity decay and the thermal field. This idea can directly be generalized in the case of multi-atom information concentration.
Bound states of quarks and gluons and hadronic transitions
International Nuclear Information System (INIS)
A potential which incorporates the concepts of confinement and asymptotic freedom, previously utilized in the description of the spectroscopy of mesons and baryons, is extended to the gluon sector. The mass spectroscopy of glueballs and hybrids is analyzed considering only pairwise potentials and massive constituent gluons. The mass spectrum of the color octet two-gluon system is adopted as a suitable description of the intermediate states of hadronic transitions, within the framework of the multipole expansion for quantum chromodynamics. The spin-dependent effects in the gluonium spectrum, associated with the Coulombian potential, are calculated through the inverted first Born approximation for the gluon-gluon scattering. (author). 102 refs, 1 fig, 13 tabs
Free energy barrier for melittin reorientation from a membrane-bound state to a transmembrane state
Irudayam, Sheeba J; Berkowitz, Max L
2013-01-01
An important step in a phospholipid membrane pore formation by melittin antimicrobial peptide is a reorientation of the peptide from a surface into a transmembrane conformation. In this work we perform umbrella sampling simulations to calculate the potential of mean force (PMF) for the reorientation of melittin from a surface-bound state to a transmembrane state and provide a molecular level insight into understanding peptide and lipid properties that influence the existence of the free energy barrier. The PMFs were calculated for a peptide to lipid (P/L) ratio of 1/128 and 4/128. We observe that the free energy barrier is reduced when the P/L ratio increased. In addition, we study the cooperative effect; specifically we investigate if the barrier is smaller for a second melittin reorientation, given that another neighboring melittin was already in the transmembrane state. We observe that indeed the barrier of the PMF curve is reduced in this case, thus confirming the presence of a cooperative effect.
Probabilistic teleportation of an arbitrary pure state of two atoms
Institute of Scientific and Technical Information of China (English)
Yang Zhen-Biao; Wu Huai-Zhi; Su Wan-Jun
2007-01-01
In the context of microwave cavity QED, this paper proposes a new scheme for teleportation of an arbitrary pure state of two atoms. The scheme is very different from the previous ones which achieve the integrated state measurement,it deals in a probabilistic but simplified way. In the scheme, no additional atoms are involved and thus only two atoms are required to be detected. The scheme can also be used for the teleportation of arbitrary pure states of many atoms or two-mode cavities.
X(3872) and Bound State Problem of D~0(D)*~0((D)~0D*~0)
Institute of Scientific and Technical Information of China (English)
LIU Tan-rui; LIU Xiang; DENG Wei-zhen
2009-01-01
We have performed a dynamical calculation of the bound state problem of D~0(D)~(*0) by considering the pion and sigma meson exchange potential.Our preliminary analysis disfavors the molecular interpretation of X(3872) if we use the experimental D~* Dπ coupling constant g=0.59 and a reasonable cutoff around 1 GeV,which is the typical hadronic scale.In contrast,there probably exists a loosely bound S-wave B (-B)~* molecular state.Such a molecular state would be rather stable since its dominant decay mode is the radiative decay through B~*→Bγ.
Effect of quasi-bound states on coherent electron transport in twisted nanowires
Cuoghi, Giampaolo; Bertoni, Andrea; Sacchetti, Andrea
2010-01-01
Quantum transmission spectra of a twisted electron waveguide expose the coupling between traveling and quasi-bound states. Through a direct numerical solution of the open-boundary Schr\\"odinger equation we single out the effects of the twist and show how the presence of a localized state leads to a Breit-Wigner or a Fano resonance in the transmission. We also find that the energy of quasi-bound states is increased by the twist, in spite of the constant section area along the waveguide. While ...
Tunable Plasmonic Reflection by Bound 1D Electron States in a 2D Dirac Metal
Jiang, B.-Y.; Ni, G. X.; Pan, C.; Fei, Z.; Cheng, B.; Lau, C. N.; Bockrath, M.; Basov, D. N.; Fogler, M. M.
2016-08-01
We show that the surface plasmons of a two-dimensional Dirac metal such as graphene can be reflected by linelike perturbations hosting one-dimensional electron states. The reflection originates from a strong enhancement of the local optical conductivity caused by optical transitions involving these bound states. We propose that the bound states can be systematically created, controlled, and liquidated by an ultranarrow electrostatic gate. Using infrared nanoimaging, we obtain experimental evidence for the locally enhanced conductivity of graphene induced by a carbon nanotube gate, which supports this theoretical concept.
Generating two-photon entangled states in a driven two-atom system
International Nuclear Information System (INIS)
We describe a mechanism for a controlled generation of a pure Bell state with correlated atoms that involve two or zero excitations. The mechanism inhibits transitions into singly excited collective states of a two-atom system by shifting them from their unperturbed energies. The shift is accomplished by the dipole-dipole interaction between the atoms. The creation of the Bell state is found to be dependent on the relaxation of the atomic excitation. When the relaxation is not present or can be ignored, the state of the system evolves harmonically between a separable to the maximally entangled state. We follow the temporal evolution of the state and find that the concurrence can be different from zero only in the presence of the dipole-dipole interaction. Furthermore, in the limit of a large dipole-dipole interaction, the concurrence reduces to that predicted for an X state of the system. A general inequality is found which shows that the concurrence of an X-state system is a lower bound for the concurrence of the two-atom system. With the relaxation present, the general state of the system is a mixed state that under a strong dipole-dipole interaction reduces the system to an X-state form. We find that mixed states admit of lower level of entanglement, and the entanglement may occur over a finite range of time. A simple analytical expression is obtained for the steady-state concurrence which shows that there is a threshold value for the dipole-dipole interaction relative to the Rabi frequency of the driving field above which the atoms can be entangled over the entire time of the evolution.
Preparation of entangled atomic states through simultaneous nonresonant atom-field interaction
Institute of Scientific and Technical Information of China (English)
Chen Mei-Feng
2006-01-01
A scheme is proposed for generating a three-atom maximal entanglement W state. It is based on the simultaneous nonresonant interaction of atoms with a single-mode cavity field. Our scheme is insensitive to the cavity field, so the cavity field in our scheme can be initially in thermal states.
Unambiguous atomic Bell measurement assisted by multiphoton states
Torres, Juan Mauricio; Bernád, József Zsolt; Alber, Gernot
2016-05-01
We propose and theoretically investigate an unambiguous Bell measurement of atomic qubits assisted by multiphoton states. The atoms interact resonantly with the electromagnetic field inside two spatially separated optical cavities in a Ramsey-type interaction sequence. The qubit states are postselected by measuring the photonic states inside the resonators. We show that if one is able to project the photonic field onto two coherent states on opposite sites of phase space, an unambiguous Bell measurement can be implemented. Thus, our proposal may provide a core element for future components of quantum information technology such as a quantum repeater based on coherent multiphoton states, atomic qubits and matter-field interaction.
FFLO Vortex Lattice States in Cold Fermionic-Atom Systems
Shim, Y. -P.; Duine, R.A.; MacDonald, A. H.
2006-01-01
Condensation of atom pairs with finite total momentum is expected in a portion of the phase diagram of a two-component fermionic cold-atom system. This unusual condensate can be identified by detecting the exotic higher Landau level (HLL) vortex lattice states it can form when rotated. With this motivation, we have solved the linearized gap equations of a polarized cold atom system in a Landau level basis to predict experimental circumstances under which HLL vortex lattice states occur.
Generation of Exotic Quantum States of a Cold Atomic Ensemble
DEFF Research Database (Denmark)
Christensen, Stefan Lund
. Furthermore, the nonclassical properties of the created state is inferred through the use of atomic quadrature quasi-probability distributions. The second generated state is a collective-single-excitation state — the atomic equivalent of a single photon. This state is created by the detection of a heralding......Over the last decades quantum effects have become more and more controllable, leading to the implementations of various quantum information protocols. These protocols are all based on utilizing quantum correlation. In this thesis we consider how states of an atomic ensemble with such correlations...... can be created and characterized. First we consider a spin-squeezed state. This state is generated by performing quantum non-demolition measurements of the atomic population difference. We show a spectroscopically relevant noise reduction of -1.7dB, the ensemble is in a many-body entangled state...
Spectral Singularities do not Correspond to Bound States in the Continuum
Directory of Open Access Journals (Sweden)
Ali Mostafazadeh
2013-01-01
Full Text Available We show that, contrary to a claim made in arXiv:1011.0645, the von Neumann-Winger bound states that lie in the continuum of the scattering states are fundamentally different from Naimark’s spectral singularities.
Study of the deeply bound hole states by the (3He,α) reaction
International Nuclear Information System (INIS)
The (3He,α) reactions at 110 - 120 MeV on even tin isotopes revealed the presence of the new (1g)-1 state at Ex = 6 -- 7 MeV with a spectroscopic factor comparable to the known (1g sub(9/2))-1 deeply bound hole state. (author)
Normalization and perturbation theory for tightly bound states of the spinor Bethe-Salpeter equation
L.G. Suttorp
1976-01-01
The normalisation integrals for the tightly-bound-state solutions of the spinor Bethe-Salpeter equation that have been derived recently are evaluated. Ghost states are found to appear when the continuous parameters characterising the type of fermion-boson interaction reach a critical value. Perturba
Search for $\\eta$'(958)-nucleus bound states by (p,d) reaction at GSI and FAIR
Fujioka, H; Benlliure, J; Brinkmann, K -T; Friedrich, S; Geissel, H; Gellanki, J; Guo, C; Gutz, E; Haettner, E; Harakeh, M N; Hayano, R S; Higashi, Y; Hirenzaki, S; Hornung, C; Igarashi, Y; Ikeno, N; Itahashi, K; Iwasaki, M; Jido, D; Kalantar-Nayestanaki, N; Kanungo, R; Knoebel, R; Kurz, N; Metag, V; Mukha, I; Nagae, T; Nagahiro, H; Nanova, M; Nishi, T; Ong, H J; Pietri, S; Prochazka, A; Rappold, C; Reiter, M P; Rodríguez-Sánchez, J L; Scheidenberger, C; Simon, H; Sitar, B; Strmen, P; Sun, B; Suzuki, K; Szarka, I; Takechi, M; Tanaka, Y K; Tanihata, I; Terashima, S; Watanabe, Y N; Weick, H; Widmann, E; Winfield, J S; Xu, X; Yamakami, H; Zhao, J
2015-01-01
The mass of the {\\eta}' meson is theoretically expected to be reduced at finite density, which indicates the existence of {\\eta}'-nucleus bound states. To investigate these states, we perform missing-mass spectroscopy for the (p, d) reaction near the {\\eta}' production threshold. The overview of the experimental situation is given and the current status is discussed.
Interaction of Interpolating Number-Coherent States with Atomic Systems
Feng, Y; Solomon, A I; Feng, Yinqi; Fu, Hongchen
1999-01-01
Interpolating number-coherent states are new states of the radiation field which interpolate between number and coherent states, to which they reduce in appropriate limits. We study some fundamental features of the interaction of these new states with a atomic system in the framework of the Jaynes-Cummings model(JCM). The dynamical evolution of atomic population inversion, field entropy, the Q-function and photon number distribution properties are investigated in detail.
Superposition States in Cavities Fed by Injected Atoms
Marian, Paulina; Marian, Tudor
1997-01-01
We study the possibility of producing disentangled states in the Jaynes-Cummings model when the input field is a superposition of two Fock states, |M〉 and |M+ 1〉, and the atom is initially in a superposition of its two stationary states. In the case of large M, we show that Jaynes-Cummings interaction provides quantum state swapping between the two qubits (atom and field).
Atomic states and properties of Ru-electrocatalyst
Institute of Scientific and Technical Information of China (English)
PENG Hong-jian; XIE You-qing; WEI De-liang
2006-01-01
Using the one-atom theory(OA), the atomic states of Ru-electrocatalyst with hcp structure was determined as [Kr](4dn)3.78(4dc)2.22(5sc)1.77(5sf)0.23. The potential curve, elasticity and the temperature dependence of linear thermal expansion coefficient and bulk modulus of hcp-Ru were calculated quantitatively. The atomic states of this metal with fcc and bcc structure and liquid state were also studied. According to its atomic states, the relationship between the atomic states and catalytic performance was explained qualitatively and these supplied Ru-metal and electrocatalyst with complete data for optimum designation in accordance with metal material systematic sicence.
International Nuclear Information System (INIS)
We propose a scheme for approximately and conditionally teleporting an unknown atomic state in cavity QED. Our scheme does not involve the Bell-state measurement and thus an additional atom is unnecessary. Only two atoms and one single-mode cavity are required. The scheme may be used to teleport the state of a cavity mode to another mode using a single atom. The idea may also be used to teleport the state of a trapped ion
Manipulating the Quantum State of a Single Cooper Pair in a One-Atom Contact
Urbina, Cristian; Janvier, Camille; Tosi, Leandro; Girit, Çağlar; Stern, Michael; Bertet, Patrice; Vion, Denis; Joyez, Philippe; Esteve, Daniel; Goffman, Marcelo; Pothier, Hugues
2015-03-01
Superconducting qubits presently used in quantum information experiments are based on Josephson tunnel junctions. Nevertheless, these circuits exploit only partially the richness of the Josephson effect, as they overlook the existence of an internal, spin-like degree of freedom, inherent to all Josephson structures. Each conduction channel of a weak-link gives rise to a doublet of discrete subgap states (the Andreev bound states), which represents the two possible states of a localized Cooper pair. We spotlight these doublets with experiments on the simplest Josephson weak-link: a one-atom contact between two superconductors. The atomic contact is inserted in a superconducting loop coupled to a microwave resonator. This standard circuit-QED architecture allows performing single shot measurements of the state of a localized Cooper pair, and to manipulate coherently its quantum state, as illustrated by Rabi oscillations, Ramsey fringes and spin echoes.
Extended supersymmetry for the bound states of the generalized Hulthen potential hierarchy
International Nuclear Information System (INIS)
Using the associated hypergeometric differential equation, we analytically solve the bound states corresponding to a hierarchy of the radial potential -v0 e-δr/(1 - e-δr) + c e-δr/(1 - e-δr)2 as a generalization of the Hulthen potential. Then, an analytic solution corresponding to a special case for which the parameter c is expected to be in terms of l(l + 1) is also derived. Meanwhile without introducing a superpotential and in the framework of supersymmetric quantum mechanics, it is shown that these bound states can be calculated by two different algebraic methods. Based on these two approaches, it is noted that the bound states realize an extended supersymmetry structure
Extended supersymmetry for the bound states of the generalized Hulthén potential hierarchy
Fakhri, H.; Chenaghlou, A.
2004-09-01
Using the associated hypergeometric differential equation, we analytically solve the bound states corresponding to a hierarchy of the radial potential -v0 e-dgrr/(1 - e-dgrr) + c e-dgrr/(1 - e-dgrr)2 as a generalization of the Hulthén potential. Then, an analytic solution corresponding to a special case for which the parameter c is expected to be in terms of l(l + 1) is also derived. Meanwhile without introducing a superpotential and in the framework of supersymmetric quantum mechanics, it is shown that these bound states can be calculated by two different algebraic methods. Based on these two approaches, it is noted that the bound states realize an extended supersymmetry structure.
Extended supersymmetry for the bound states of the generalized Hulthen potential hierarchy
Energy Technology Data Exchange (ETDEWEB)
Fakhri, H [Institute for Studies in Theoretical Physics and Mathematics (IPM), PO Box 19395-5531, Tehran (Iran, Islamic Republic of); Chenaghlou, A [Institute for Studies in Theoretical Physics and Mathematics (IPM), PO Box 19395-5531, Tehran (Iran, Islamic Republic of)
2004-09-03
Using the associated hypergeometric differential equation, we analytically solve the bound states corresponding to a hierarchy of the radial potential -v{sub 0} e{sup -{delta}}{sup r}/(1 - e{sup -{delta}}{sup r}) + c e{sup -{delta}}{sup r}/(1 - e{sup -{delta}}{sup r}){sup 2} as a generalization of the Hulthen potential. Then, an analytic solution corresponding to a special case for which the parameter c is expected to be in terms of l(l + 1) is also derived. Meanwhile without introducing a superpotential and in the framework of supersymmetric quantum mechanics, it is shown that these bound states can be calculated by two different algebraic methods. Based on these two approaches, it is noted that the bound states realize an extended supersymmetry structure.
Critical field enhancement of asymptotic optical bound states in the continuum
Yoon, Jae Woong; Song, Seok Ho; Magnusson, Robert
2015-12-01
We study spectral singularities and critical field enhancement factors associated with embedded photonic bound states in subwavelength periodic Si films. Ultrahigh-Q resonances supporting field enhancement factor exceeding 108 are obtained in the spectral vicinity of exact embedded eigenvalues in spite of deep surface modulation and vertical asymmetry of the given structure. Treating relations between the partial resonance Q and field enhancement factors with an analytical coupled-mode model, we derive a general strategy to maximize the field enhancement associated with these photonic bound states in the presence of material dissipation. The analytical expression for the field enhancement quantitatively agrees with rigorous numerical calculations. Therefore, our results provide a general knowledge for designing practical resonance elements based on optical bound states in the continuum in various applications.
Propagators for Scalar Bound States at Finite Temperature in an NJL Model
Institute of Scientific and Technical Information of China (English)
ZHOU BangRong
2002-01-01
We re-examine physical causal propagators for scalar and pseudoscalar bound states at finite temperaturein a chiral Ut(1) x UR(1) NJL model, defined by four-point amputated fimctions subtracted through the gap equation,and prove that they are completely equivalent in the imaginary-time and real-time formalisms by separating carefiullythe imaginary part of the zero-temperature loop integral. It is shown that the same thermal transformation matrix ofthe matrix propagators for these bound states in the real-time formalism is precisely the one of the matrix propagatorfor an elementary scalar particle and this fact shows the similarity of thermodynamic property between a composite andelementary scalar particle. The retarded and advanced propagators for these bound states are also given explicitly fromthe imaginary-time formalism.
Preparation of Multi—Atom Entangled States with a Single Cavity in a Thermal State
Institute of Scientific and Technical Information of China (English)
ZHENGShi－Biao
2002-01-01
A scheme is suggested for the generation of multi-atom maximally entangled states with a cavity in a thermal state,In this scheme several appropriately prepared two-level atoms are simultaneously sent through the nonresonant cavity.We divide the whole atom-cavity interaction time into two equal parts.At the end of the first part a π pulse is applied to the atome using a classical field.Then the photon-number-dependent shifts on the atomic states are cancelled and the atomic system finally evoloves to a maximally entangled state.
Feasible Teleportation Schemes with Five-Atom Entangled State
International Nuclear Information System (INIS)
Teleportation schemes with a five-atom entangled state are investigated. In the teleportation scheme Bell state measurements (BSMs) are difficult for physical realization, so we investigate another strategy using separate measurements instead of BSM based on cavity quantum electrodynamics techniques. The scheme of two-atom entangled state teleportation is a controlled and probabilistic one. For the teleportation of the three-atom entangled state, the scheme is a probabilistic one. The fidelity and the probability of the successful teleportation are also obtained.
Feasible Teleportation Schemes with Five-Atom Entangled State
Institute of Scientific and Technical Information of China (English)
XUE Zheng-Yuan; YI You-Min; CAO Zhuo-Liang
2006-01-01
Teleportation schemes with a five-atom entangled state are investigated. In the teleportation scheme Bell state measurements (BSMs) are difficult for physical realization, so we investigate another strategy using separate measurements instead of BSM based on cavity quantum electrodynamics techniques. The scheme of two-atom entangled state teleportation is a controlled and probabilistic one. For the teleportation of the three-atom entangled state, the scheme is a probabilistic one. The fidelity and the probability of the successful teleportation are also obtained.
Manipulating atomic states via optical orbital angular-momentum
Institute of Scientific and Technical Information of China (English)
2008-01-01
Optical orbital angular-momentum(OAM)has more complex mechanics than the spin degree of photons,and may have a broad range of application.Manipulating atomic states via OAM has become an interesting topic.In this paper,we first review the general theory of generating adiabatic gauge field in ultracold atomic systems by coupling atoms to external optical fields with OAM,and point out the applications of the generated adiabatic gauge field.Then,we review our work in this field,including the generation of macroscopic superposition of vortex-antivortex states and spin Hall effect(SHE)in cold atoms.
Bound states in the continuum and spin filter in quantum-dot molecules
Energy Technology Data Exchange (ETDEWEB)
Ramos, J.P. [Departamento de Física, Universidad Católica del Norte, Casilla 1280, Antofagasta (Chile); Orellana, P.A., E-mail: pedro.orellana@usm.cl [Departamento de Física, Universidad Técnica Federico Santa María, Vicuña Mackenna 3939, Santiago (Chile)
2014-12-15
In this paper we study the formation of bound states in the continuum in a quantum dot molecule coupled to leads and their potential application in spintronics. Based on the combination of bound states in the continuum and Fano effect, we propose a new design of a spin-dependent polarizer. By lifting the spin degeneracy of the carriers in the quantum dots by means of a magnetic field the system can be used as a spin-polarized device. A detailed analysis of the spin-dependent conductance and spin polarization as a function of the applied magnetic field and gate voltages is carried out.
Three-particle hyper-spherical harmonics and quark bound states
Salom, Igor; Dmitrašinović, V.
2016-01-01
We construct the three-body permutation symmetric hyperspherical harmonics based on the subgroup chain S3 ⊗ SO (3)rot ⊂ O(2) ⊗ SO (3)rot ⊂ O(6) (and the subalgebra chain u(1) ⊗ so(3)rot ⊂ u(3) ⊂ so(6)). These hyperspherical harmonics represent a natural basis for solving non-relativistic three-body Schrodinger equation in three spatial dimensions. In particular, we apply the calculated three-particle harmonics to the three-quark bound state problem. We consider confining Δ- and Y-string three-quark effective potentials, and then calculate the spectrum of low-lying (K < 4) bound states.
Bound states of the $\\phi^4$ model via the Non-Perturbative Renormalization Group
Rose, F; Leonard, F; Delamotte, B
2016-01-01
Using the nonperturbative renormalization group, we study the existence of bound states in the symmetry-broken phase of the scalar $\\phi^4$ theory in all dimensions between two and four and as a function of the temperature. The accurate description of the momentum dependence of the two-point function, required to get the spectrum of the theory, is provided by means of the Blaizot--M\\'endez-Galain--Wschebor approximation scheme. We confirm the existence of a bound state in dimension three, with a mass within 1% of previous Monte-Carlo and numerical diagonalization values.
Propagators for scalar bound states at finite temperature in a NJL model
Zhou Bang Rong
2002-01-01
We show that, in a chiral $U_L(1)\\times U_R(1)$ NJL model, the physical propagators at finite temperature for scalar and pseudoscalar bound states in the imaginary-time formalism defined by amputated four-point functions, may have identical expressions to corresponding ones in the real-time formalism defined by diagonalization of amputated four-point function matrices only if the momentum $p$ of those bound states satisfy the condition $0\\leq p^2 < 4m^2$ ($m$ is the dynamical fermion mass). In the other case, the propagators in the two formalisms will have different imaginary parts in their denominators.
Scattering integral equations and four nucleon problem. Four nucleon bound states and scattering
International Nuclear Information System (INIS)
Existing results from the application of integral equation technique four-nucleon bound states and scattering are reviewed. The purpose of this review is to provide a clear and elementary introduction in the integral equation method and to demonstrate its usefulness in physical applications. Developments in the actual numerical solutions of Faddeev-Yakubovsky type equations are such that a detailed comparison can be made with experiment. Bound state calculations indicate that a nonrelativistic description with pairwise nuclear forces does not suffice and additional degrees of freedom are noted
Bound states in the (2+1)D scalar electrodynamics with Chern-Simons term
International Nuclear Information System (INIS)
This work studies the existence of bound states for the 3-dimensions scalar electrodynamics, with the Chern-Simons. Quantum field theory is used for calculation of the Mfi scattering matrices, in the non-relativistic approximation. The field propagators responsible for the interaction in the scattering processes have been calculated, and scattering matrices have been constructed. After obtaining the scattering matrix, the cross section in the quantum field theory has been compared with the quantum mechanic cross section in the Born approximation, allowing to obtain the form of the potential responsible for the interactions in the scattering processes. The possibility of bound states are analyzed by using the Schroedinger equation
International Nuclear Information System (INIS)
We present high-precision trap loss spectroscopy of excited Na2 molecules obtained by the photoassociation of ultracold sodium atoms. Near the 3 2S+3 2P3/2 dissociation limit, hyperfine and rotational (Coriolis-type) interactions cause significant mixing of states of different nominal Hund's case (c) symmetry resulting in a complex pattern of spectral lines. We construct a theoretical model of the large, slowly rotating molecule starting from a long-range, atomic viewpoint. Interaction potentials are derived from the known long-range resonant dipole and van der Waals forces between atoms, supplemented at short range by the results of ab initio electronic-structure calculations. Spin-dependent interactions coupling the various angular momenta--nuclear spin, electron spin, electron orbit, and the mechanical rotation of the molecule as a whole--are derived from known atomic parameters. We avoid imposing approximate symmetries or coupling schemes and consequently include all nonadiabatic mixing of different degrees of freedom. Quantitative agreement between experiment and theory for both line positions and intensities is found. Specifically, we observe and calculate mixing of levels of 0g-, 0u+, and 1g symmetry bound by 2S+3 2P3/2 asymptote
Bichromatic State-insensitive Trapping of Caesium Atoms
Metbulut, M. M.; Renzoni, F.
2015-01-01
State-insensitive dipole trapping of multilevel atoms can be achieved by an appropriate choice of the wavelength of the trapping laser, so that the interaction with the different transitions results in equal AC Stark shifts for the ground and excited states of interest. However this approach is severely limited by the availability of coherent sources at the required wavelength and of appropriate power. This work investigates state-insensitive trapping of caesium atoms for which the required w...
Shell-model description of weakly bound and unbound nuclear states
International Nuclear Information System (INIS)
A consistent description of weakly bound and unbound nuclei requires an accurate description of the particle continuum properties when carrying out multiconfiguration mixing. This is the domain of the Gamow Shell Model (GSM) which is the multiconfigurational shell model in the complex k-plane formulated using a complete Berggren ensemble representing bound single-particle (s.p.) states, s.p. resonances, and non-resonant complex energy continuum states. We discuss the salient features of effective interactions in weakly bound systems and show selected applications of the GSM formalism to p-shell nuclei. Finally, a development of the new non-perturbative scheme based on Density Matrix Renormalization Group methods to select the most significant continuum configurations in GSM calculations is discussed shortly. (orig.)
Heavy quark bound states in a quark-gluon plasma: dissociation and recombination
Blaizot, Jean-Paul; Faccioli, Pietro; Garberoglio, Giovanni
2015-01-01
We present a comprehensive approach to the dynamics of heavy quarks in a quark gluon plasma, including the possibility of bound state formation and dissociation. In this exploratory paper, we restrict ourselves to the case of an Abelian plasma, but the extension of the techniques used to the non Abelian case is straightforward. A chain of well defined approximations leads eventually to a generalized Langevin equation, where the force and the noise terms are determined from a correlation function of the equilibrium plasma, and depend explicitly on the configuration of the heavy quarks. We solve the Langevin equation for various initial conditions, various numbers of heavy quark-antiquark pairs, and various temperatures of the plasma. Results of simulations illustrate various expected phenomena: dissociation of bound states as a result of combined effects of screening of the potential and collisions with the plasma constituent, formation of bound pairs (recombination) that occurs when enough heavy quarks are pr...
Bound-state formation for thermal relic dark matter and unitarity
International Nuclear Information System (INIS)
We show that the relic abundance of thermal dark matter annihilating via a long-range interaction, is significantly affected by the formation and decay of dark matter bound states in the early universe, if the dark matter mass is above a few TeV . We determine the coupling required to obtain the observed dark matter density, taking into account both the direct 2-to-2 annihilations and the formation of bound states, and provide an analytical fit. We argue that the unitarity limit on the inelastic cross-section is realized only if dark matter annihilates via a long-range interaction, and we determine the upper bound on the mass of thermal-relic dark matter to be about 197 (139) TeV for (non)-self-conjugate dark matter
Bound states of multi-nucleon channels in N_f=2+1 lattice QCD
Yamazaki, Takeshi; Kuramashi, Yoshinobu; Ukawa, Akira
2012-01-01
We calculate the energies for multi-nucleon ground states with the nuclear mass number less than or equal to 4 in 2+1 flavor QCD at the lattice spacing of a = 0.09 fm employing a relatively heavy quark mass corresponding to m_pi = 0.51 GeV. We investigate the volume dependence of the energy shift of the ground state and the state of free nucleons to distinguish a bound state from attractive scattering states. From the investigation we conclude that ^4He, ^3He, deuteron and dineutron are bound at m_pi = 0.51 GeV. We compare their binding energies with those in our quenched studies and also with some recent investigations.
Preparation of Multi-Atom Entangled States with a Single Cavity in a Thermal State
Institute of Scientific and Technical Information of China (English)
ZHENG Shi-Biao
2002-01-01
A scheme is suggested for the generation of multi-atom maximally entangled states with a cavity in a thermalstate. In this scheme several appropriately prepared two-level atoms are simultaneously sent through the nonresonantcavity. We divide the whole atom-cavity interaction time into two equal parts. At the end of the first part a π pulse isapplied to the atoms using a classical field. Then the photon-number-dependent shifts on the atomic states are cancelledand the atomic system finally evolves to a maximally entangled state.
Probabilistic teleportation of an unknown atomic state
Institute of Scientific and Technical Information of China (English)
叶柳; 郭光灿
2002-01-01
We propose two schemes for teleporting an unknown state. In our schemes, a three-particle Greenberger-Horne-Zeilinger state is used as a quantum channel. We show that the probabilistic teleportation of an unknown quantum state can be realized.
Detection of Individual Proteins Bound along DNA Using Solid-State Nanopores.
Plesa, Calin; Ruitenberg, Justus W; Witteveen, Menno J; Dekker, Cees
2015-05-13
DNA in cells is heavily covered with all types of proteins that regulate its genetic activity. Detection of DNA-bound proteins is a challenge that is well suited to solid-state nanopores as they provide a linear readout of the DNA and DNA-protein volume in the pore constriction along the entire length of a molecule. Here, we demonstrate that we can realize the detection of even individual DNA-bound proteins at the single-DNA-molecule level using solid-state nanopores. We introduce and use a new model system of anti-DNA antibodies bound to lambda phage DNA. This system provides several advantages since the antibodies bind individually, tolerate high salt concentrations, and will, because of their positive charge, not translocate through the pore unless bound to the DNA. Translocation of DNA-antibody samples reveals the presence of short 12 μs current spikes within the DNA traces, with amplitudes that are about 4.5 times larger than that of dsDNA, which are associated with individual antibodies. We conclude that transient interactions between the pore and the antibodies are the primary mechanism by which bound antibodies are observed. This work provides a proof-of-concept for how nanopores could be used for future sensing applications. PMID:25928590
Teleportation of Atomic States in a Vacuum-Induced Environment
Institute of Scientific and Technical Information of China (English)
LIU Jin; SHAO Bin; XIANG Shao-Hua; ZOU Jian
2009-01-01
We present a scheme for teleporting atomic state through a dissipative quantum channel induced by spontaneous emission and investigate the destructive effect of the atomic decay on the success probability and the fidelity of teleportation associated to different channels. It is found that there exists an optimal channel to realize faithful teleportation.
Teleportation of atomic states with a weak coherent cavity field
Institute of Scientific and Technical Information of China (English)
Zheng Shi-Biao
2005-01-01
A scheme is proposed for the teleportation of an unknown atomic state. The scheme is based on the resonant interaction of atoms with a coherent cavity field. The mean photon-number of the cavity field is much smaller than one and thus the cavity decay can be effectively suppressed. Another adwntage of the scheme is that only one cavity is required.
Atomic quantum superposition state generation via optical probing
DEFF Research Database (Denmark)
Nielsen, Anne Ersbak Bang; Poulsen, Uffe Vestergaard; Negretti, Antonio;
2009-01-01
We analyze the performance of a protocol to prepare an atomic ensemble in a superposition of two macroscopically distinguishable states. The protocol relies on conditional measurements performed on a light field, which interacts with the atoms inside an optical cavity prior to detection, and we...
Spin-dipole induced lifetime of the least-bound quintet sigma state of He(2S)+He(2S)
Beams, T J; Whittingham, I B; Beams, Timothy J.; Peach, Gillian; Whittingham, Ian B.
2006-01-01
The properties of the least-bound vibrational level (v=14) of the quintet sigma state formed during the ultracold collision of two spin-polarized metastable helium atoms are crucial to studies of photoassociation spectroscopy of metastable helium. We report a calculation of the autoionization lifetime of this state induced by spin-dipole coupling of the quintet sigma state to the singlet sigma state from which Penning and associative ionization processes are highly probable. We find a lifetime of about 150 microseconds, significantly larger than the recent experimental estimates of (4-5) microseconds.
DEFF Research Database (Denmark)
Frier, Christian; Damkilde, Lars
A method of conducting lower bound Limit State analysis is to apply the interior-point method. The aim of the paper is to refine the method by reducing the number of optimization variables considerably by eliminating the equilibrium equations a priori. Another new idea is to adapt a spatially...
Bound State Solutions of Klein-Gordon Equation with the Kratzer Potential
Institute of Scientific and Technical Information of China (English)
M. Ko(c)ak
2007-01-01
The relativistic problem of spinless particle subject to a Kratzer potential is analysed. Bound state solutions for s-waves are found by separating the Klein-Gordon equation into two parts. Unlike the similar works in the literature, the separation make it possible to see explicitly the relativistic contributions, if any, to the solution in the non-relativistic limit.
Another comment on 'relativistic description of quark-antiquark bound states'
International Nuclear Information System (INIS)
We point out some ambiguities in the treatment of fermion-antifermion bound states by solving the reduced Salpeter equation in coordinate space. Our observations allow to cast some doubt on the validity of the conclusion of Gara et al. that moving from a nonrelativistic to a relativistic description makes things worse. (authors)
Exact solutions of the spinor Bethe-Salpeter equation for tightly bound states
L.G. Suttorp
1975-01-01
Exact solutions are obtained for the spinor Bethe-Salpeter equation that describes tightly bound states of spin-/sup 1///sub 2/ fermions with massless-boson exchange. The corresponding coupling constants form a discrete spectrum that depends continuously on the parameters characterizing the type of
Modelling light-cone distribution amplitudes from non-relativistic bound states
International Nuclear Information System (INIS)
We calculate light-cone distribution amplitudes for non-relativistic bound states, including radiative corrections from relativistic gluon exchange to first order in the strong coupling constant. We distinguish between bound states of quarks with equal (or similar) mass, m1 ∼ m2, and between bound states where the quark masses are hierarchical, m1 >> m2. For both cases we calculate the distribution amplitudes at the non-relativistic scale and discuss the renormalization-group evolution for the leading-twist and 2-particle distributions. Our results apply to hard exclusive reactions with non-relativistic bound states in the QCD factorization approach like, for instance, Bc → ηclν or e+e- → J/ψηc. They also serve as a toy model for light-cone distribution amplitudes of light mesons or heavy B and D mesons, for which certain model-independent properties can be derived. In particular, we calculate the anomalous dimension for the B meson distribution amplitude φB-(ω) in the Wandzura-Wilczek approximation and derive the according solution of the evolution equation at leading logarithmic accuracy
Liu, H; Glöckle, W; Elster, Ch.
2002-01-01
The Faddeev equations for the three-body bound state are solved directly as thre e-dimensional integral equations without employing partial wave decomposition. Two-body forces of the Malfliet-Tjon type and simple spin independent genuine three-body forces are considered for the calculation of the three-body binding energy.
Bound states of the Dirac equation with some physical potentials by the Nikiforov-Uvarov method
Energy Technology Data Exchange (ETDEWEB)
Setare, Mohammad R; Haidari, S [Department of Physics, University of Kurdistan, Pasdaran Avenue, Sanandaj (Iran, Islamic Republic of)], E-mail: rezakord@ipm.ir, E-mail: heidary.somayeh@gmail.com
2010-01-15
Exact analytical solutions for the s-wave Dirac equation with the reflectionless-type, Rosen-Morse and Manning-Rosen potentials are obtained, under the condition of spin symmetry. We obtained bound state energy eigenvalues and corresponding spinor wave function in the framework of the Nikiforov-Uvarov (NU) method.
Resonances from QCD bound states and the 750 GeV diphoton excess
Kats, Yevgeny; Strassler, Matthew J.
2016-05-01
Pair production of colored particles is in general accompanied by production of QCD bound states (onia) slightly below the pair-production threshold. Bound state annihilation leads to resonant signals, which in some cases are easier to see than the decays of the pair-produced constituents. In a previous paper ( arXiv:1204.1119 URL"/> ) we estimated the bound state signals, at leading order and in the Coulomb approximation, for particles with various spins, color representations and electric charges, and used 7 TeV ATLAS and CMS resonance searches to set rough limits. Here we update our results to include 8 and 13 TeV data. We find that the recently reported diphoton excesses near 750 GeV could indeed be due to a bound state of this kind. A narrow resonance of the correct size could be obtained for a color-triplet scalar with electric charge -4/3 and mass near 375GeV, if (as a recent lattice computation suggests) the wave function at the origin is somewhat larger than anticipated. Pair production of this particle could have evaded detection up to now. Other candidates may include a triplet scalar of charge 5/3, a triplet fermion of charge -4/3, and perhaps a sextet scalar of charge -2/3.
The bound-state Aharonov-Bohm effect around a cosmic string revisited
International Nuclear Information System (INIS)
In this Letter we observe that the self-adjoint extension of the Hamiltonian of a particle moving around a cosmic string gives rise to a gravitational analogue of the bound-state Aharonov-Bohm effect without the need of confining walls
The Bound State S-matrix of the Deformed Hubbard Chain
de Leeuw, Marius; Matsumoto, Takuya
2011-01-01
In this work we use the q-oscillator formalism to construct the atypical (short) supersymmetric representations of the centrally extended Uq (su(2|2)) algebra. We then determine the S-matrix describing the scattering of arbitrary bound states. The crucial ingredient in this derivation is the affine extension of the aforementioned algebra.
Applying the relativistic quantization condition to a three-particle bound state in a periodic box
Hansen, Maxwell T
2016-01-01
Using our recently developed relativistic three-particle quantization condition, we study the finite-volume energy shift of a three-particle bound state. We reproduce the result obtained using non-relativistic quantum mechanics by Mei{\\ss}ner, R{\\'i}os and Rusetsky, and generalize the result to a moving frame.
Orthogonality-condition model for bound states with a separable expansion of the potential
International Nuclear Information System (INIS)
A very efficient solution of the equation of Saito's orthogonality-condition model (OCM) is reported for bound states by means of a separable expansion of the potential (PSE method). Some simplifications of the published formulae of the PSE method is derived, which facilitate its application to the OCM and may be useful in solving the Schroedinger equation as well. (author)
Coherent manipulation of Andreev states in superconducting atomic contacts
Janvier, C.; Tosi, L.; Bretheau, L.; Girit, Ç. Ö.; Stern, M.; Bertet, P.; Joyez, P.; Vion, D.; Esteve, D.; Goffman, M.F.; Pothier, H.; Urbina, C.
2015-01-01
Coherent control of quantum states has been demonstrated in a variety of superconducting devices. In all these devices, the variables that are manipulated are collective electromagnetic degrees of freedom: charge, superconducting phase, or flux. Here, we demonstrate the coherent manipulation of a quantum system based on Andreev bound states, which are microscopic quasiparticle states inherent to superconducting weak links. Using a circuit quantum electrodynamics setup we perform single-shot r...
Institute of Scientific and Technical Information of China (English)
ZHONG Zhi-Rong
2008-01-01
A scheme to teleport a superposition of three orthogonal states of an atom without Bell-state measurement in cavity QED is proposed. The scheme based on the resonant interaction of two A-type three-level atoms with a bimodal cavity. The detection of atom a collapses atom b to the initial state of atom a with cavity mode left in two-mode vacuum state.The probability of success and the fidelity of this scheme are 0.112 and 0.999,respectively.
International Nuclear Information System (INIS)
The first experimental observation of bound-state beta-decay showed, that due solely to the electron stripping, a stable nuclide, e.g. 163Dy, became unstable. Also a drastic modification of the half-life of bare 187Re, from 4.12(2) x 1010 years down to 32.9(20) years, could be observed. It was mainly due to the possibility for the mother nuclide to decay into a previously inaccessible nuclear level of the daughter nuclide. It was proposed to study a nuclide where this decay mode was competing with continuum-state beta-decay, in order to measure their respective branchings. The ratio βb/βc could also be evaluated for the first time. 207Tl was chosen due to its high atomic number, and Q-value of about 1.4 MeV, small enough to enhance the βb probability and large enough to allow the use of time-resolved Schottky Mass Spectrometry (SMS) to study the evolution of mother and bound-state beta-decay daughter ions. The decay properties of the ground state and isomeric state of 207Tl81+ have been investigated at the GSI accelerator facility in two separate experiments. For the first time β-decay where the electron could go either to a bound state (atomic orbitals) and lead to 207Pb81+ as a daughter nuclide, or to a continuum state and lead to 207Pb82+, has been observed. The respective branchings of these two processes could be measured as well. The deduced total nuclear half-life of 255(17) s for 207Tl81+, was slightly modified with respect to the half-life of the neutral atom of 286(2) s. It was nevertheless in very good agreement with calculations based on the assumption that the beta-decay was following an allowed type of transition. The branching βb/βc=0.192(20), was also in very good agreement with the same calculations. The application of stochastic precooling allowed to observe in addition the 1348 keV short-lived isomeric state of 207Tl. The half-life of this isomeric state was measured as 1.47(32) s, which shows a small deviation compared to the half-life for
Quantum Cloning of an Unknown 2-Atom State via Entangled Cluster States
Yu, L.-z.; Zhong, F.
2016-06-01
This paper presented a scheme for cloning a 2-atom state in the QED cavity with the help of Victor who is the state's preparer. The cloning scheme has two steps. In the first step, the scheme requires probabilistic teleportation of a 2-atom state that is unknown in advance, and uses a 4-atom cluster state as quantum channel. In the second step, perfect copies of the 2-atom entangled state may be realized with the assistance of Victor. The finding is that our scheme has two outstanding advantages: it is not sensitive to the cavity decay, and Bell state is easy to identify.
Quantum Cloning of an Unknown 2-Atom State via Entangled Cluster States
Yu, L.-z.; Zhong, F.
2016-01-01
This paper presented a scheme for cloning a 2-atom state in the QED cavity with the help of Victor who is the state's preparer. The cloning scheme has two steps. In the first step, the scheme requires probabilistic teleportation of a 2-atom state that is unknown in advance, and uses a 4-atom cluster state as quantum channel. In the second step, perfect copies of the 2-atom entangled state may be realized with the assistance of Victor. The finding is that our scheme has two outstanding advantages: it is not sensitive to the cavity decay, and Bell state is easy to identify.
Ground-State Entanglement Bound for Quantum Energy Teleportation of General Spin-Chain Models
Hotta, Masahiro
2013-01-01
In protocols of quantum energy teleportation (QET), ground-state entanglement of many-body systems plays a crucial role. For a general class of spin-chain systems, we show analytically that the entanglement entropy is lower bounded by a positive quadratic function of the teleported energy between the regions of a QET protocol. This supports a general conjecture that ground-state entanglement is an evident physical resource for energy transportation in the context of QET
The lower bound to the concurrence for four-qubit W state under noisy channels
Espoukeh, Pakhshan; Pedram, Pouria
2015-01-01
We study the dynamics of four-qubit W state under various noisy environments by solving analytically the master equation in the Lindblad form in which the Lindblad operators correspond to the Pauli matrices and describe the decoherence of states. Also, we investigate the dynamics of the entanglement using the lower bound to the concurrence. It is found that while the entanglement decreases monotonically for Pauli-Z noise, it decays suddenly for other three noises. Moreover, by studying the ti...
Reflection algebra, Yangian symmetry and bound-states in AdS/CFT
MacKay, Niall
2011-01-01
We present the `Heisenberg picture' of the reflection algebra by explicitly constructing the boundary Yangian symmetry of the AdS/CFT superstring ending on a boundary with degrees of freedom and preserving all of the bulk symmetry algebra. This enables us to present the bound-state reflection matrices in a more elegant, rapidity-difference form. We also consider the spectrum of bulk and boundary states and some automorphisms of the underlying algebras.
Dark Entangled Steady States of Interacting Rydberg Atoms
DEFF Research Database (Denmark)
Dasari, Durga; Mølmer, Klaus
2013-01-01
their short-lived excited states lead to rapid, dissipative formation of an entangled steady state. We show that for a wide range of physical parameters, this entangled state is formed on a time scale given by the strengths of coherent Raman and Rabi fields applied to the atoms, while it is only weakly...
Vibrational autodetachment spectroscopy of Au-6 : Image-charge-bound states of a gold ring
International Nuclear Information System (INIS)
Spectral experiments on mass-selected negative cluster ions of gold and silver were performed in the wavelength range near the threshold for one-photon photodetachment of the extra electron. The Au-6 cluster ion displayed a uniquely well resolved spectrum consisting of a progression in a single vibrational mode. Details of this threshold photodetachment spectrum and the associated photoelectron energy distribution suggest an explanation based on autodetachment from totally symmetric vibrational levels of very weakly bound excited electronic state (bound by image charge forces) of the Au-6 cluster in the form of a planar, six-fold symmetric, gold ring
Bound states of breathing Airy-Gaussian beams in nonlocal nonlinear medium
Zhang, Xiaping
2016-05-01
With a nonlocal model, we investigate the propagation dynamics of a single Airy-Gaussian (AiG) beam and their interaction in one-dimensional condition by means of direct numerical simulations. With the split-step Fourier method, numerical results shows that nonlocality can support periodic intensity distribution of AiG beams leading to the formation of stable bound states. Especially, by tuning the phase difference between the two beams, we can steer the center of the bound AiG beams in nonlocal nonlinear media.
Bounds for the state-modulated resolvent of a linear Boltzmann generator
Clark, Jeremy
2011-01-01
We study a generalized resolvent for the generator of a Markovian semigroup. The Markovian generator appears in a linear Boltzmann equation modeling a one-dimensional test particle in a periodic potential and colliding elastically with particles from an ideal background gas. We obtain bounds for the state-modulated resolvent which are relevant in the regime where the mass ratio between the test particle and a particle from the gas is large. These bounds relate to the typical amount of time that the particle spends in different regions of phase space before arriving to a region around the origin.
A Goppa-like bound on the trellis state complexity of algebraic geometric codes
Munuera, Carlos; Torres, Fernando
2002-01-01
For a linear code $\\cC$ of length $n$ and dimension $k$, Wolf noticed that the trellis state complexity $s(\\cC)$ of $\\cC$ is upper bounded by $w(\\cC):=\\min(k,n-k)$. In this paper we point out some new lower bounds for $s(\\cC)$. In particular, if $\\cC$ is an Algebraic Geometric code, then $s(\\cC)\\geq w(\\cC)-(g-a)$, where $g$ is the genus of the underlying curve and $a$ is the abundance of the code.
Free-bound electron exchange contribution to l-split atomic structure in dense plasmas
International Nuclear Information System (INIS)
An analytical expression for the exchange energy between the bound electron in hydrogen-like ions and the free electrons of plasma is proposed. Two limiting cases are identified: 1) the low temperature limit where the energy depends linearly on density and on the ion charge as 1/Z2 but does not depend on the temperature itself, 2) the high temperature limit where the energy depends on temperature as 1/T but does not depend on the ion charge. These two regimes are separated by a characteristic temperature (T* = 4Z2Ry) which is a universal parameter depending only on the charge Z of the ions. We presented numerical results for aluminum: the exchange energy contributes about 15% to the total plasma energy and can reach an order of 10-4 of the total transition energy. Comparison to the Local-density Approximation (Kohn-Sham) exchange energy shows a good agreement. (authors)
Lower bounds for ballistic current and noise in non-equilibrium quantum steady states
Directory of Open Access Journals (Sweden)
Benjamin Doyon
2015-03-01
Full Text Available Let an infinite, homogeneous, many-body quantum system be unitarily evolved for a long time from a state where two halves are independently thermalized. One says that a non-equilibrium steady state emerges if there are nonzero steady currents in the central region. In particular, their presence is a signature of ballistic transport. We analyze the consequences of the current observable being a conserved density; near equilibrium this is known to give rise to linear wave propagation and a nonzero Drude peak. Using the Lieb–Robinson bound, we derive, under a certain regularity condition, a lower bound for the non-equilibrium steady-state current determined by equilibrium averages. This shows and quantifies the presence of ballistic transport far from equilibrium. The inequality suggests the definition of “nonlinear sound velocities”, which specialize to the sound velocity near equilibrium in non-integrable models, and “generalized sound velocities”, which encode generalized Gibbs thermalization in integrable models. These are bounded by the Lieb–Robinson velocity. The inequality also gives rise to a bound on the energy current noise in the case of pure energy transport. We show that the inequality is satisfied in many models where exact results are available, and that it is saturated at one-dimensional criticality.
Bound states of massive fermions in Aharonov-Bohm-like fields
Energy Technology Data Exchange (ETDEWEB)
Khalilov, V.R. [Moscow State University, Faculty of Physics, Moscow (Russian Federation)
2014-01-15
Bound states of massive fermions in Aharonov-Bohm (AB)-like fields have analytically been studied. The Hamiltonians with the (AB)-like potentials are essentially singular and therefore require specification of a one-parameter self-adjoint extension. We construct self-adjoint Dirac Hamiltonians with the AB potential in 2+1 dimensions that are specified by boundary conditions at the origin. It is of interest that for some range of the extension parameter the AB potential can bind relativistic charged massive fermions. The bound-state energy is determined by the AB magnetic flux and depends upon the fermion spin and extension parameter; it is a periodical function of the magnetic flux. We also construct self-adjoint Hamiltonians for the so-called Aharonov-Casher (AC) problem, show that nonrelativistic neutral massive fermions can be bound by the (AC) background, determine the range of the extension parameter in which fermion bound states exist, and find their energies as well as wave functions. (orig.)
Bound states of massive fermions in the Aharonov--Bohm-like fields
Khalilov, V R
2014-01-01
Bound states of massive fermions in the Aharonov-Bohm like fields have analytically been studied. The Hamiltonians with the Aharonov--Bohm like potentials are essentially singular and therefore require specification of a one-parameter self-adjoint extension. We construct self-adjoint Dirac Hamiltonians with the Aharonov-Bohm (AB) potential in 2+1 dimensions that are specified by boundary conditions at the origin. It is of interest that for some range of extension parameter the AB potential can bind relativistic charged massive fermions. The bound-state energy is determined by the AB magnetic flux and depends upon fermion spin and extension parameter; it is a periodical function of the magnetic flux. We also construct self-adjoint Hamiltonians for the so-called Aharonov-Casher (AC) problem, show that nonrelativistic neutral massive fermions can be bound by the Aharonov-Casher background, determine the range of extension parameter in which fermion bound states exist and find their energies as well as wave funct...
Lower bounds for ballistic current and noise in non-equilibrium quantum steady states
Energy Technology Data Exchange (ETDEWEB)
Doyon, Benjamin, E-mail: benjamin.doyon@kcl.ac.uk
2015-03-15
Let an infinite, homogeneous, many-body quantum system be unitarily evolved for a long time from a state where two halves are independently thermalized. One says that a non-equilibrium steady state emerges if there are nonzero steady currents in the central region. In particular, their presence is a signature of ballistic transport. We analyze the consequences of the current observable being a conserved density; near equilibrium this is known to give rise to linear wave propagation and a nonzero Drude peak. Using the Lieb–Robinson bound, we derive, under a certain regularity condition, a lower bound for the non-equilibrium steady-state current determined by equilibrium averages. This shows and quantifies the presence of ballistic transport far from equilibrium. The inequality suggests the definition of “nonlinear sound velocities”, which specialize to the sound velocity near equilibrium in non-integrable models, and “generalized sound velocities”, which encode generalized Gibbs thermalization in integrable models. These are bounded by the Lieb–Robinson velocity. The inequality also gives rise to a bound on the energy current noise in the case of pure energy transport. We show that the inequality is satisfied in many models where exact results are available, and that it is saturated at one-dimensional criticality.
Lower bounds for ballistic current and noise in non-equilibrium quantum steady states
International Nuclear Information System (INIS)
Let an infinite, homogeneous, many-body quantum system be unitarily evolved for a long time from a state where two halves are independently thermalized. One says that a non-equilibrium steady state emerges if there are nonzero steady currents in the central region. In particular, their presence is a signature of ballistic transport. We analyze the consequences of the current observable being a conserved density; near equilibrium this is known to give rise to linear wave propagation and a nonzero Drude peak. Using the Lieb–Robinson bound, we derive, under a certain regularity condition, a lower bound for the non-equilibrium steady-state current determined by equilibrium averages. This shows and quantifies the presence of ballistic transport far from equilibrium. The inequality suggests the definition of “nonlinear sound velocities”, which specialize to the sound velocity near equilibrium in non-integrable models, and “generalized sound velocities”, which encode generalized Gibbs thermalization in integrable models. These are bounded by the Lieb–Robinson velocity. The inequality also gives rise to a bound on the energy current noise in the case of pure energy transport. We show that the inequality is satisfied in many models where exact results are available, and that it is saturated at one-dimensional criticality
Relativistic description of quark-antiquark bound states. Spin-independent treatment
International Nuclear Information System (INIS)
We present the results of a detailed study of light- and heavy-quark--antiquark bound states in the context of the reduced Bethe-Salpeter equation with static vector and scalar interactions. In the present paper, we consider the spin-averaged spectra. Spin effects are considered in a separate paper. We find that this approach, although apparently successful for the heavy-quark b bar b and c bar c states, fails for the s bar s, l bar l, and light-heavy states. The reasons for the failure are intrinsic to the method, as we discuss. Difficulties are already evident for the c bar c states
Proximity-induced interface bound states in superconductor-graphene junctions
Burset, P.; Herrera, W.; Levy Yeyati, A.
2009-07-01
We show that interface bound states are formed at isolated graphene-superconductor junctions. These states arise due to the interplay of virtual Andreev and normal reflections taking place at these interfaces. Simple analytical expressions for their dispersion are obtained considering interfaces formed along armchair or zig-zag edges. It is shown that the states are sensitive to a supercurrent flowing on the superconducting electrode. The states provide long-range superconducting correlations on the graphene layer, which may be exploited for the detection of crossed Andreev processes.
Ionization and bound-state relativistic quantum dynamics in laser-driven multiply charged ions
Energy Technology Data Exchange (ETDEWEB)
Hetzheim, Henrik
2009-01-14
The interaction of ultra-strong laser fields with multiply charged hydrogen-like ions can be distinguished in an ionization and a bound dynamics regime. Both are investigated by means of numerically solving the Dirac equation in two dimensions and by a classical relativistic Monte-Carlo simulation. For a better understanding of highly nonlinear physical processes the development of a well characterized ultra-intense relativistic laser field strength has been driven forward, capable of studying e.g. the magnetic field effects of the laser resulting in an additional electron motion in the laser propagation direction. A novel method to sensitively measure these ultra-strong laser intensities is developed and employed from the optical via the UV towards the XUV frequency regime. In the bound dynamics field, the determination of multiphoton transition matrixelements has been investigated between different bound states via Rabi oscillations. (orig.)
Ionization and bound-state relativistic quantum dynamics in laser-driven multiply charged ions
International Nuclear Information System (INIS)
The interaction of ultra-strong laser fields with multiply charged hydrogen-like ions can be distinguished in an ionization and a bound dynamics regime. Both are investigated by means of numerically solving the Dirac equation in two dimensions and by a classical relativistic Monte-Carlo simulation. For a better understanding of highly nonlinear physical processes the development of a well characterized ultra-intense relativistic laser field strength has been driven forward, capable of studying e.g. the magnetic field effects of the laser resulting in an additional electron motion in the laser propagation direction. A novel method to sensitively measure these ultra-strong laser intensities is developed and employed from the optical via the UV towards the XUV frequency regime. In the bound dynamics field, the determination of multiphoton transition matrixelements has been investigated between different bound states via Rabi oscillations. (orig.)
Autoionizing States of Atoms Calculated Using Generalized Sturmians
DEFF Research Database (Denmark)
Avery, James Emil; Avery, John Scales
2005-01-01
The generalized Sturmian method is applied to autoionizing states of atoms and ions. If the Goscinskian basis sets allow for a sufficient amount of angular correletion, the calculated energies of doubly-excited (autoionizing) states are found to agree well with the few available experimental...... energies. A large-Z approximation is discussed, and simple formulas are derived which are valid not only for autoionizing states, but for all states of an isoelectronic atomic series. Diagonalization of a small block of the interelectron repulsion matrix yields roots that can be used for a wide range of Z...
Atomic Coherence in the Micromaser Injected with Slow V-type Three-State Atoms: Emission Probability
Institute of Scientific and Technical Information of China (English)
ZHANG Zhi-Ming; LIANG Wen-Qing; XIE Sheng-Wu
2001-01-01
The effects of atomic coherence on the single-mode two-photon rnicromaser injected with slow V-type three-state atoms are studied for the first time. It is shown that the atomic coherence can modify the atomic emission probability. The effects of the atomic centre-of-mass momentum, the cavity length and other parameters are also studied.
Institute of Scientific and Technical Information of China (English)
Yang Zhen-Biao; Wu Huai-Zhi; Su Wan-Jun; Zhong Zhi-Rong; Zheng Shi-Biao
2007-01-01
This paper shows that, based on the single-photon JC model depicting the resonant interaction of a two-level atom with a single cavity mode, an unknown atomic state and cavity photon superposition state can be faithfully teleported with only a single measurement. The scheme is probabilistic, its success lies on the event that the sender atom (or the medi-atom, for teleportation of cavity field state) is detected in the higher state. The scheme is in contrast to the previous ones of using a maximally two-particle entangled state as quantum channel.
Schwinger functions and light-quark bound states, and sigma terms
Höll, A; Roberts, C D; Wright, S V
2006-01-01
We explore the viability of using solely spacelike information about a Schwinger function to extract properties of bound states. In a concrete example it is not possible to determine properties of states with masses \\gsim 1.2 GeV. Modern Dyson-Schwinger equation methods supply a well-constrained tool that provide access to hadron masses and \\sigma-terms. We report values of the latter for a range of hadrons. Of interest is analysis relating to a u,d scalar meson, which is compatible with a picture of the lightest 0^{++} as a bound state of a dressed-quark and -antiquark supplemented by a material pion cloud. A constituent-quark \\sigma-term is defined, which affords a means for assessing the flavour-dependence of dynamical chiral symmetry breaking.
Skyrmion-induced bound states on the surface of three-dimensional topological insulators
Andrikopoulos, Dimitrios; Sorée, Bart; De Boeck, Jo
2016-05-01
The interaction between the surface of a 3D topological insulator and a skyrmion/anti-skyrmion structure is studied in order to investigate the possibility of electron confinement due to the skyrmion presence. Both hedgehog (Néel) and vortex (Bloch) skyrmions are considered. For the hedgehog skyrmion, the in-plane components cannot be disregarded and their interaction with the surface state of the topological insulator (TI) has to be taken into account. A semi-classical description of the skyrmion chiral angle is obtained using the variational principle. It is shown that both the hedgehog and the vortex skyrmion can induce bound states on the surface of the TI. However, the number and the properties of these states depend strongly on the skyrmion type and the skyrmion topological number NSk. The probability densities of the bound electrons are also derived where it is shown that they are localized within the skyrmion region.
Bound States of (Anti-)Scalar-Quarks in $SU(3)_{c}$ Lattice QCD
Iida, H; Takahashi, T T
2007-01-01
Light scalar-quarks \\phi (colored scalar particles or idealized diquarks) and their color-singlet hadronic states are studied with quenched SU(3)_c lattice QCD in terms of mass generation. We investigate ``scalar-quark mesons'' \\phi^\\dagger \\phi and ``scalar-quark baryons'' \\phi\\phi\\phi as the bound states of scalar-quarks \\phi. We also investigate the bound states of scalar-quarks \\phi and quarks \\psi, i.e., \\phi^\\dagger \\psi, \\psi\\psi\\phi and \\phi\\phi\\psi, which we name ``chimera hadrons''. All the new-type hadrons including \\phi are found to have a large mass due to large quantum corrections by gluons, even for zero bare scalar-quark mass m_\\phi=0 at a^{-1}\\sim 1{\\rm GeV}. We conjecture that all colored particles generally acquire a large effective mass due to dressed gluon effects.
Small QCD corrections in inclusive O-+ quarkonium decay for the bound state renormalization scheme
International Nuclear Information System (INIS)
A consistent field theoretic computation of the first order correction to the total decay of a nonrelativistic heavy quarkonium state must consider contributions from the annihilation amplitude, with a typical scale of the order of the quark mass m, and from the bound state wave-function, where the typical scale is of the order of the Bohr-momentum αsub(s)m. Therefore, not only the latter smaller scale is the one to be taken for the total decay rate, but also a quite specific renormalization, the 'bound-state renormalization scheme', must be used for a computation of the total inclusive decay rate of O-+ → hadrons. Due the important cancellations between large individual contributions, the net result turns out to be small, encouraging the use of pure perturbative QCD in such systems. (Author)
Ghost-gluon and ghost-quark bound states and their role in BRST quartets
Alkofer, Natalia
2011-01-01
A non-perturbative version of the BRST quartet mechanism in infrared Landau gauge QCD is proposed for transverse gluons and quarks. Based on the positivity violation for transverse gluons the content of the respective non-perturbative BRST quartet is derived. To identify the gluon's BRST-daughter and second parent state, a truncated Bethe-Salpeter equation for the gluon-(anti-)ghost bound state is investigated. We comment shortly on several equivalent forms of this equation. Repeating the same construction for quarks leads to a truncated Bethe-Salpeter equation for a fundamentally charged quark-(anti-)ghost bound state. It turns out that a cardinal input to this equation is given by the fully dressed quark-gluon vertex, and that it is indispensable to dress the quark-gluon vertex in this equation in order to obtain a consistent truncation.
Afzal, Muhammad Imran; Lee, Yong Tak
2016-01-01
Von Neumann and Wigner theorized bounding of asymmetric eigenstates and anti-crossing of symmetric eigenstates. Experiments have shown that owing to anti-crossing and similar radiation rates, graphene-like resonance of inhomogeneously strained photonic eigenstates can generate pseudomagnetic field, bandgaps and Landau levels, while dissimilar rates induce non-Hermicity. Here, we showed experimentally higher-order supersymmetry and quantum phase transitions by resonance between similar one dimensional lattices. The lattices consisted of inhomgeneously strain-like phases of triangular solitons. The resonance created two dimensional inhomogeneously deformed photonic graphene. All parent eigenstates are annihilated. Where eigenstates of mildly strained solitons are annihilated with similar (power law) rates through one tail only and generated Hermitianally bounded eigenstates. The strongly strained solitons, positive defects are annihilated exponentially through both tails with dissimilar rates. Which bounded eig...
International Nuclear Information System (INIS)
Nonrelativistic fixed-core valence-shell configuration interaction calculations are carried out for excited states of atomic negative ions in the range H through Ca, in an effort to identify the ones which are metastable against autoionization. Approximate relativistic corrections are included in some cases. From Be onwards, all (Core)sub(n)(n + 1)ssup(q)(n + 1)psup(r) neutrals appear to bind an extra electron into a bound (Core)sub(n)(n + 1)ssup(q)(n + 1)psup(r+1 2 + 1)L negative ion, in all cases where the sup(2S + 1)L continuum starts at the corresponding neutral atom state. Similarly as in the recently discussed case of Li-, alkali-earths (Be-, Mg-, Ca-), Zn-, B-, Al-, C-, Si-, Ar-, and possibly S-, have two bound excited states connected by an E1 transition in regions extending from infrared to vacuum ultraviolet. Negative neon is found to decay by E1 radiation into a continuum, thus Ne- beams are unlikely to be made in the future. However, there exists a metastable [Ne]3p54s4p 4S state of negative argon, making possible the production of Ar- beams. (orig.)
Energy Technology Data Exchange (ETDEWEB)
Bunge, C.F.; Galan, M.; Jauregui, R. (Universidad Nacional Autonoma de Mexico, Mexico City. Inst. de Fisica); Bunge, A.V. (Universidad Autonoma Metropolitana, Mexico City. Dept. de Quimica)
1982-11-01
Nonrelativistic fixed-core valence-shell configuration interaction calculations are carried out for excited states of atomic negative ions in the range H through Ca, in an effort to identify the ones which are metastable against autoionization. Approximate relativistic corrections are included in some cases. From Be onwards, all (Core)sub(n)(n + 1)ssup(q)(n + 1)psup(r) neutrals appear to bind an extra electron into a bound (Core)sub(n)(n + 1)ssup(q)(n + 1)psup(r+1 2 + 1)L negative ion, in all cases where the sup(2S + 1)L continuum starts at the corresponding neutral atom state. Similarly as in the recently discussed case of Li/sup -/, alkali-earths (Be/sup -/, Mg/sup -/, Ca/sup -/), Zn/sup -/, B/sup -/, Al/sup -/, C/sup -/, Si/sup -/, Ar/sup -/, and possibly S/sup -/, have two bound excited states connected by an E1 transition in regions extending from infrared to vacuum ultraviolet. Negative neon is found to decay by E1 radiation into a continuum, thus Ne/sup -/ beams are unlikely to be made in the future. However, there exists a metastable (Ne)3p/sup 5/4s4p /sup 4/S state of negative argon, making possible the production of Ar/sup -/ beams.
Crystal structure of a Na+-bound Na+,K+-ATPase preceding the E1P state.
Kanai, Ryuta; Ogawa, Haruo; Vilsen, Bente; Cornelius, Flemming; Toyoshima, Chikashi
2013-10-10
Na(+),K(+)-ATPase pumps three Na(+) ions out of cells in exchange for two K(+) taken up from the extracellular medium per ATP molecule hydrolysed, thereby establishing Na(+) and K(+) gradients across the membrane in all animal cells. These ion gradients are used in many fundamental processes, notably excitation of nerve cells. Here we describe 2.8 Å-resolution crystal structures of this ATPase from pig kidney with bound Na(+), ADP and aluminium fluoride, a stable phosphate analogue, with and without oligomycin that promotes Na(+) occlusion. These crystal structures represent a transition state preceding the phosphorylated intermediate (E1P) in which three Na(+) ions are occluded. Details of the Na(+)-binding sites show how this ATPase functions as a Na(+)-specific pump, rejecting K(+) and Ca(2+), even though its affinity for Na(+) is low (millimolar dissociation constant). A mechanism for sequential, cooperative Na(+) binding can now be formulated in atomic detail. PMID:24089211
Single-Atom Gating of Quantum State Superpositions
Energy Technology Data Exchange (ETDEWEB)
Moon, Christopher
2010-04-28
The ultimate miniaturization of electronic devices will likely require local and coherent control of single electronic wavefunctions. Wavefunctions exist within both physical real space and an abstract state space with a simple geometric interpretation: this state space - or Hilbert space - is spanned by mutually orthogonal state vectors corresponding to the quantized degrees of freedom of the real-space system. Measurement of superpositions is akin to accessing the direction of a vector in Hilbert space, determining an angle of rotation equivalent to quantum phase. Here we show that an individual atom inside a designed quantum corral1 can control this angle, producing arbitrary coherent superpositions of spatial quantum states. Using scanning tunnelling microscopy and nanostructures assembled atom-by-atom we demonstrate how single spins and quantum mirages can be harnessed to image the superposition of two electronic states. We also present a straightforward method to determine the atom path enacting phase rotations between any desired state vectors. A single atom thus becomes a real-space handle for an abstract Hilbert space, providing a simple technique for coherent quantum state manipulation at the spatial limit of condensed matter.
The C(Q0?) scenario: bound sharp positron decay, its resonant inverse, and sharp lines from β++Atom
International Nuclear Information System (INIS)
The Composite Particle (Q0?) Scenario is a phenomenology for the ''e+e-) Puzzle''. It implies a new ''Supercomposite'' molecule, the neutral C(Q0?) particle bound to a nuclear ion. From such a molecule a C(Q0?) particle may decay by the process of Sharp Annihilative Positron Emission: the e- is captured into a Bohr orbit and only a single energetic e+ emerges. The inverse is Recoilless Resonant Positron Absorption which can encompass the sharp electron lines observed in β+ irradiation of heavy atoms within the same scenario. Thus emerges the expanded ''Sharp Lepton Problem'', accessible experimentally via both β+ irradiation and high-Z heavy ion collisions. (By Occam's razor we here assume that the particle is in fact Quadronium: Q0=(e+e+e-e-).) ((orig.))
International Nuclear Information System (INIS)
For the system consisting of a neutral Dirac particle with anomalous magnetic moment, interacting with a fixed magnetic monopole, zero-energy bound states are constructed for each possible value of the total angular momentum. Results of Kazama and Yang for the charge--monopole system are used to deduce the existence of other bound states for this system, when the mass of the bound particle is nonzero. In the zero-mass case, there are no other bound states, but there are resonant states, and these are determined exactly. A noncompact, so(3,2) symmetry algebra of the zero-energy bound states is given for the finite-mass case and for the zero-mass case. In each case the infinite number of such states is associated with an irreducible Majorana representation of the algebra
Majorana bound states from exceptional points in non-topological superconductors
San-Jose, Pablo; Cayao, Jorge; Prada, Elsa; Aguado, Ramón
2016-02-01
Recent experimental efforts towards the detection of Majorana bound states have focused on creating the conditions for topological superconductivity. Here we demonstrate an alternative route, which achieves fully localised zero-energy Majorana bound states when a topologically trivial superconductor is strongly coupled to a helical normal region. Such a junction can be experimentally realised by e.g. proximitizing a finite section of a nanowire with spin-orbit coupling, and combining electrostatic depletion and a Zeeman field to drive the non-proximitized (normal) portion into a helical phase. Majorana zero modes emerge in such an open system without fine-tuning as a result of charge-conjugation symmetry, and can be ultimately linked to the existence of ‘exceptional points’ (EPs) in parameter space, where two quasibound Andreev levels bifurcate into two quasibound Majorana zero modes. After the EP, one of the latter becomes non-decaying as the junction approaches perfect Andreev reflection, thus resulting in a Majorana dark state (MDS) localised at the NS junction. We show that MDSs exhibit the full range of properties associated to conventional closed-system Majorana bound states (zero-energy, self-conjugation, 4π-Josephson effect and non-Abelian braiding statistics), while not requiring topological superconductivity.
Pion as a Longitudinal Axial-Vector Meson $q\\bar{q}$ Bound State
Pham, T N
2013-01-01
The success of the Adler-Bell-Jackiw(ABJ) chiral anomaly prediction for $\\pi^{0}\\to \\gamma\\gamma$ decay rate shows that non-anomaly terms would make a negligible contribution to the decay rate, in agreement with the Sutherland-Veltman theorem. Thus the conventional $q\\bar{q}$ bound-state description of the pion could not be valid since it would produce a $\\pi^{0}\\to \\gamma\\gamma$ decay amplitude not suppressed in the soft pion limit, in contradiction with the Sutherland-Veltman theorem. Therefore, if the pion is to be treated as a $q\\bar{q}$ bound state, this bound state would be a longitudinal axial-vector meson. In this paper, we consider the pion to be a longitudinal axial-vector meson $q\\bar{q}$ state with derivative coupling for the pion-$q\\bar{q}$ Bethe-Salpeter(BS) amplitude. We shall show that, the longitudinal axial-vector meson solution for the pion $q\\bar{q}$ Bethe-Salpeter wave function could produce a suppressed $\\pi^{0}\\to \\gamma\\gamma$ decay amplitude in the soft pion limit, in agreement with t...
The relativistic bound states of the hyperbolical potential with the centrifugal term
Energy Technology Data Exchange (ETDEWEB)
Wei Gaofeng [Department of Physics, Xi' an University of Arts and Science, Xi' an 710065 (China); Liu Xuyang [School of Physics, Suranaree University of Technology, Nakhon Ratchasima 30000 (Thailand)], E-mail: fgwei_2000@163.com, E-mail: lxy_gzu2005@126.com
2008-12-15
The approximately analytical bound state solutions of the arbitrary l-wave Klein-Gordon and arbitrary k-state Dirac equations for the mixed hyperbolical potentials are carried out by taking a proper approximate expansion of the centrifugal term. The analytical radial wavefunctions of the l-wave Klein-Gordon and k-state Dirac equations for the mixed hyperbolical potentials are presented and the corresponding energy equations are derived. Two special cases of the Klein-Gordon equation are discussed briefly.
Electronic state of helium atoms in nickel metal
International Nuclear Information System (INIS)
The molecular orbital calculations are carried out for model clusters to investigate the electronic state of the interstitial helium atoms implanted into nickel metal. The computational method used is the discrete variational Xα (DV-Xα) method. In order to study the difference in the electronic structures of helium atoms between at the tetrahedral site and at the octahedral one, the computations are performed using model clusters, Ni4He and Ni6He. The bond strength is evaluated by the use of Mulliken population analysis. The computations are also carried out for the larger cluster Ni14He to investigate the size effect of the cluster model. Furthermore, the electronic structure of the He9 cluster in Ni metal is studied, using the Ni14He9 cluster model which includes both of tetrehedral and octahedral interstitial He atoms. This paper discusses the interactions between He and Ni atoms when both interstitial He atoms coexist. (orig.)
State selective electron capture by highly stripped ions from atoms
International Nuclear Information System (INIS)
An experimental study on final-state distribution in one-electron capture from slow fully-stripped and hydrogen-like projectile ions from H and He atoms is discussed. After a short review of the available results, state-selectiveness of the process is interpreted using the Landau-Zener model
Harwell's atomic, molecular and solid state computer programs
International Nuclear Information System (INIS)
This document is intended to introduce the computational facilities available in the fields of atomic, molecular the solid state theory on the IBM370/165 at Harwell. The programs have all been implemented and thoroughly tested by the Theory of Solid State Materials Group. (author)
Teleportation of atomic entangled states with a thermal cavity
Institute of Scientific and Technical Information of China (English)
Zheng Xiao-Juan; Fang Mao-Fa; Cai Jian-Wu; Liao Xiang-Ping
2006-01-01
We propose a most simple and experimentally feasible scheme for teleporting unknown atomic entangled states in driven cavity quantum electrodynamics (QED). In our scheme, the joint Bell-state measurement (BSM) is not required,and the successful probability can reach 1.0. Furthermore, the scheme is insensitive to the cavity decay and the thermal field.
The quark-gluon vertex in Landau gauge bound-state studies
Energy Technology Data Exchange (ETDEWEB)
Williams, Richard [Justus-Liebig University of Giessen, Institute of Theoretical Physics, Giessen (Germany)
2015-05-15
We present a practical method for the solution of the quark-gluon vertex for use in Bethe-Salpeter and Dyson-Schwinger calculations. The efficient decomposition into the necessary covariants is detailed, with the numerical algorithm outlined for both real and complex Euclidean momenta. A truncation of the quark-gluon vertex, that neglects explicit back-coupling to enable the application to bound-state calculations, is given together with results for the quark propagator and quark-gluon vertex for different quark flavours. The relative impact of the various components of the quark-gluon vertex is highlighted with the flavour dependence of the effective quark-gluon interaction obtained, thus providing insight for the construction of phenomenological models within the rainbow ladder. Finally, we solve the corresponding Green's functions for complex Euclidean momenta as required in future bound-state calculations. (orig.)
Looking for bound states and resonances in the $\\eta^\\prime K\\bar K$ system
Torres, A Martínez
2016-01-01
Motivated by the continuous experimental investigations of $X(1835)$ in three-body decay channels like $\\eta^\\prime \\pi^+ \\pi^-$, we investigate the $\\eta^\\prime K \\bar K$ system with the aim of searching for bound states and/or resonances when the dynamics involved in the $K\\bar K$ subsystem can form the resonances: $f_0(980)$ in isospin 0 or $a_0(980)$ in isospin 1. For this, we solve the Faddeev equations for the three-body system. The input two-body $t$-matrices are obtained by solving Bethe-Salpeter equations in a coupled channel formalism. As a result, no signal of a three-body bound state or resonance is found.
Bound states for multiple Dirac-δ wells in space-fractional quantum mechanics
Energy Technology Data Exchange (ETDEWEB)
Tare, Jeffrey D., E-mail: jeffreytare@gmail.com; Esguerra, Jose Perico H., E-mail: pesguerra@nip.upd.edu.ph [National Institute of Physics, University of the Philippines, Diliman, Quezon City 1101 (Philippines)
2014-01-15
Using the momentum-space approach, we obtain bound states for multiple Dirac-δ wells in the framework of space-fractional quantum mechanics. Introducing first an attractive Dirac-comb potential, i.e., Dirac comb with strength −g (g > 0), in the space-fractional Schrödinger equation we show that the problem of obtaining eigenenergies of a system with N Dirac-δ wells can be reduced to a problem of obtaining the eigenvalues of an N × N matrix. As an illustration we use the present matrix formulation to derive expressions satisfied by the bound-state energies of N = 1, 2, 3 delta wells. We also obtain the corresponding wave functions and express them in terms of Fox's H-function.
Das, Priyam; Khan, Ayan; Panigrahi, Prasanta K.
2016-05-01
We study the dispersion mechanism (Lieb-mode excitation) of both single and two-component Bose-Einstein condensates, subject to an external trap in a mean-field approach, where the second quantized Lieb-mode is realized as grey soliton. Through the coupling between the centre of mass motion (Kohn mode) and the soliton's momenta arising from the kinematic chirp, induced by time modulated trap, we realize the exotic negative mass regime of the solitonic excitation. We show that the expulsive parabolic trap significantly modifies the energy-momentum dispersion in the low momenta regime, where these modes can be clearly identified, opening up the possibility to observe the Lieb-mode excitation. In case of two-component, we demonstrate the controlled formation of a bound state, in presence of an expulsive harmonic trap, through the shape compatibility of grey and bright solitons. Possible application of such a bound state to information storage and retrieval is pointed out.
Excited states of muonium in atomic hydrogen
Indian Academy of Sciences (India)
V S Kulhar
2006-06-01
Muonium formation in excited states in muon-hydrogen charge-exchange collision is investigated using a method developed in a previous paper. Differential cross-section results are found to resemble positronium formation cross-section results of positron-hydrogen charge-exchange problem. Forward differential and integrated cross-sections are computed for muon energy of 2 keV and higher. Total muonium formation cross-sections are computed using Jackson and Schiff scaling rules. Muonium formation cross-section results obtained from proton-hydrogen charge-exchange cross-section results, using velocity scaling are compared with the results of the present calculation.
Mapping trilobite state signatures in atomic hydrogen
Pérez-Ríos, Jesús; Eiles, Matthew T.; Greene, Chris H.
2016-07-01
A few-body approach relying on static line broadening theory is developed to treat the spectroscopy of a single Rydberg excitation to a trilobite-like state immersed in a high density ultracold medium. The present theoretical framework implements the recently developed compact treatment of polyatomic Rydberg molecules, allowing for an accurate treatment of a large number of perturbers within the Rydberg orbit. This system exhibits two unique spectral signatures: its lineshape depends on the Rydberg quantum number n but, strikingly, is independent of the density of the medium, and it is characterized by sharply peaked features reflecting the oscillatory structure of the potential energy landscape.
Three-photon coherence of Rydberg atomic states
Kwak, Hyo Min; Jeong, Taek; Lee, Yoon-Seok; Moon, Han Seb
2016-05-01
We investigated three-photon coherence effects of the Rydberg state in a four-level ladder-type atomic system for the 5 S1/2 (F = 3) - 5 P3/2 (F' = 4) - 50 D5/2 - 51 P3/2 transition of 85 Rb atoms. By adding a resonant electric field of microwave (MW) at electromagnetically induced transparency (EIT) in Rydberg state scheme, we observed experimentally that splitting of EIT signal appears under the condition of three-photon resonance in the Doppler-broadened atomic system. Discriminating the two- and three-photon coherence terms from the calculated spectrum in a simple four-level ladder-type Doppler-broadened atomic system, we found that the physical origin of splitting of EIT was three-photon coherence effect, but not three-photon quantum interference phenomena such as three-photon electromagnetically induced absorption (TPEIA).
The lower bound to the concurrence for four-qubit W state under noisy channels
Espoukeh, Pakhshan; Pedram, Pouria
2015-02-01
We study the dynamics of four-qubit W state under various noisy environments by solving analytically the master equation in the Lindblad form in which the Lindblad operators correspond to the Pauli matrices and describe the decoherence of states. Also, we investigate the dynamics of the entanglement using the lower bound to the concurrence. It is found that while the entanglement decreases monotonically for Pauli-Z noise, it decays suddenly for other three noises. Moreover, by studying the time evolution of entanglement of various maximally entangled four-qubit states, we indicate that the four-qubit W state is more robust under same-axis Pauli channels. Furthermore, three-qubit W state preserves more entanglement with respect to the four-qubit W state, except for the Pauli-Z noise.
Optimal Portfolios in Lévy Markets under State-Dependent Bounded Utility Functions
Figueroa-López, José E.; Jin Ma
2010-01-01
Motivated by the so-called shortfall risk minimization problem, we consider Merton's portfolio optimization problem in a non-Markovian market driven by a Lévy process, with a bounded state-dependent utility function. Following the usual dual variational approach, we show that the domain of the dual problem enjoys an explicit “parametrization,” built on a multiplicative optional decomposition for nonnegative supermartingales due to Föllmer and Kramkov (1997). As a key step we...
Properties of bound states of the Schroedinger equation with attractive Dirac delta potentials
Energy Technology Data Exchange (ETDEWEB)
Demiralp, Ersan [Physics Department, Bogazici University, Bebek, 34342 Istanbul (Turkey); Beker, Haluk [Physics Department, Bogazici University, Bebek, 34342 Istanbul (Turkey)
2003-07-04
We have studied bound states of the Schroedinger equation for an attractive potential with any finite number (P) of Dirac delta-functions in R{sup n} where n = 1, 2, 3, .... The potential is radially symmetric for n {>=} 2 and is given as V(r) = - h-bar {sup 2}/2m {sigma}{sup P}{sub i=1} {sigma}{sub i}{delta}(r - r{sub i}) where {sigma}{sub i} > 0, r{sub 1} < r{sub 2} < c < r{sub P}, and r{sub i} element of (0, +{infinity}) for n {>=} 2, r{sub i} element of (-{infinity}, +{infinity}) for n 1. By separating angular degrees of freedom, the radial equation is obtained for n {>=} 2 and applications of the boundary conditions lead to P transfer matrices which are used to form an equation for the eigenvalues. We have proven that, for given n and l, the bound state solutions of the radial equation are non-degenerate and there are at most P bound state solutions of the radial equation and hence P bound state energy levels for a potential with P attractive Dirac delta-functions. Given l and n {>=} 2, for P = 1, we have shown that there exists one and only one solution of the radial equation if {sigma}{sub 1} r{sub 1} > 2l + n - 2 and none otherwise. We have also proven that there are at most P positive roots for the equation X{sub 22}(k) = 0 where X ({sup X{sub 1}{sub 1X{sub 2}{sub 1}X{sub 1}{sub 2X{sub 2}{sub 2}}) = M{sub P}M{sub P-1} ... M{sub 1} and M{sub i} element of SL(2, R) are the particular transfer matrices mentioned above.
Dissecting zero modes and bound states on BPS vortices in Ginzburg-Landau superconductors
Alonso-Izquierdo, Alberto; Guilarte, Juan Mateos
2016-01-01
In this paper the zero modes of fluctuation of cylindrically symmetric self-dual vortices are analyzed and described in full detail. These BPS topological defects arise at the critical point between Type II and Type I superconductors, or, equivalently, when the masses of the Higgs particle and the vector boson in the Abelian Higgs model are equal. In addition, novel bound states of Higss and vector bosons trapped by the self-dual vortices at their core are found and investigated.
Dimensionality of space, bound-state postulate and the conservation of baryons and leptons
International Nuclear Information System (INIS)
By demanding that the laws of nature be such that the three-dimensionality of space can be deduced from them, it is shown within the framework of general relativity that gravity should be attractive and that there should be stable bound states. There is a discussion of the consistency with this requirement of the conservation of baryons and leptons. It is also proposed that some new gravitational behavior limits the formation of black holes which would violate baryon and lepton conservation
Dimensionality of space, bound-state postulate and the conservation of baryons and leptons
International Nuclear Information System (INIS)
By demanding that the laws of nature be such that the three-dimensionality of space can be deduced from them, it is shown within the framework of general relativity theory that gravity should be attractive and that there should be stable bound states. There is a discussion of the consistency with this requirement of the conservation of baryons and leptons. It is also proposed that some new gravitational behaviour limits the formation of black holes which would violate baryon and lepton conservation
Quasi-bound states of Schrodinger and Dirac electrons in magnetic quantum dot
Masir, M. Ramezani; Matulis, A.; Peeters, F. M.
2009-01-01
The properties of a two-dimensional electron are investigated in the presence of a circular step magnetic field profile. Both electrons with parabolic dispersion as well as Dirac electrons with linear dispersion are studied. We found that in such a magnetic quantum dot no electrons can be confined. Nevertheless close to the Landau levels quasi-bound states can exist with a rather long life time.
Study of -nucleus interaction through the formation of -nucleus bound state
Indian Academy of Sciences (India)
V Jha; B J Roy; A Chatterjee; H Machner
2006-05-01
The question of possible existence of -mesic nuclei is quite intriguing. Answer to this question will deeply enrich our understanding of -nucleus interaction which is not so well-understood. We review the experimental efforts for the search of -mesic nuclei and describe the physics motivation behind it. We present the description of an experiment for the search of -nucleus bound state using the GeV proton beam, currently being performed at COSY.
Second quantization method in the presence of bound states of particles
Peletminskii, Sergey V.; Slyusarenko, Yuriy V.
2006-01-01
We develop an approximate second quantization method for describing the many-particle systems in the presence of bound states of particles at low energies (the kinetic energy of particles is small in comparison to the binding energy of compound particles). In this approximation the compound and elementary particles are considered on an equal basis. This means that creation and annihilation operators of compound particles can be introduced. The Hamiltonians, which specify the interactions betw...
K{sup -} nuclear quasi-bound states in a chirally motivated coupled-channel approach
Energy Technology Data Exchange (ETDEWEB)
Mares, Jiri, E-mail: mares@ujf.cas.cz [Nuclear Physics Institute (Czech Republic)
2012-05-15
K{sup }- nuclear optical potentials are constructed from in-medium K-bar N scattering amplitudes within a chirally motivated coupled-channel model. The strong energy and density dependence of the scattering amplitudes at and below threshold leads to K{sup }- potential depths -Re V{sub K{sup -}}({rho}{sub 0}) approx. 80 - 100 MeV. Self consistent calculations of K{sup }- nuclear quasi-bound states are discussed.
Two Gamma Decay Width of D Meson in Bound State Model
International Nuclear Information System (INIS)
We have estimated the two gamma decay width of D meson by using the bound state model of Holdom and Sutherland. Here we have derived an effective quark level Lagrangian for c → uγ and c → uγγ and hence we have calculated the decay width of D → γγ. We have obtained the branching ratio for the above decay mode as: Br (Do → 2γ) 8.63 x 10-6. (author)
Electroproduction of strangeness on (Lambda)H-3,4 bound states on helium
Energy Technology Data Exchange (ETDEWEB)
F. Dohrmann; D. Abbott; A. Ahmidouch; P. Ambrozewicz; C. S. Armstrong; J. Arrington; R. Asaturyan; K. Assamagan; S. Avery; K. Bailey; S. Beedoe; H. Bitao; H. Breuer; D. S. Brown; R. Carlini; J. Cha; N. Chant; E. Christy; A. Cochran; L. Cole; G. Collins; C. Cothran; J. Crowder; W. J. Cummings; S. Danagoulian; F. Duncan; J. Dunne; D. Dutta; T. Eden; M. Elaasar; R. Ent; L. Ewell; H. Fenker; H. T. Fortune; Y. Fujii; L. Gan; H. Gao; K. Garrow; D. F. Geesaman; P. Gueye; K. Gustafsson; K. Hafidi; J. O. Hansen; W. Hinton; H. E. Jackson; H. Juengst; C. Keppel; A. Klein; D. Koltenuk; Y. Liang; J. H. Liu; A. Lung; D. Mack; R. Madey; P. Markowitz; C. J. Martoff; D. Meekins; J. Mitchell; T. Miyoshi; H. Mkrtchyan; R. Mohring; S. K. Mtingwa; B. Mueller; T. G. O& #x27; Neill; G. Niculescu; I. Niculescu; D. Potterveld; J. W. Price; B. A. Raue; P. E. Reimer; J. Reinhold;
2005-05-01
The A(e,eK+)X reaction has been investigated at Jefferson Laboratory. Data were taken for Q{sup 2} approx. 0.35 GeV{sup 2} at a beam energy of 3.245 GeV for 1H,3He and 4He targets. Evidence for Lambda-hypernuclear bound states is seen for 3,4He targets. This is the first time that the electroproduction of these hypernuclei has been observed.
Vertical D4-D2-D0 bound states on K3 fibrations and modularity
Bouchard, Vincent; Diaconescu, Duiliu-Emanuel; Doran, Charles; Quigley, Callum; Sheshmani, Artan
2016-01-01
An explicit formula is derived for the generating function of vertical D4-D2-D0 bound states on smooth K3 fibered Calabi-Yau threefolds, generalizing previous results of Gholampour and Sheshmani. It is also shown that this formula satisfies strong modularity properties, as predicted by string theory. This leads to a new construction of vector valued modular forms which exhibits some of the features of a generalized Hecke transform.
Relativistic theory of di-Holeums - quantized gravitational bound states of two micro black holes
Chavda, A. L.; Chavda, L. K.
2014-01-01
The Klein-Gordon equation is solved for di-Holeums (gravitational bound states of two micro black holes) for scalar and vector gravity in its static limit. The relativistic models confirm the predictions of the nonrelativistic Newtonian gravity model, correct to about six significant figures over almost the entire sub-Planck domain. All three models possess a mass range devoid of physics. This is interpreted as evidence that the universe must have more than four dimensions. We show that the f...
A search for deeply-bound kaonic nuclear states at J-PARC
Ajimura, S.; Beer, G.; Bhang, H.; Bragadireanu, M.; Buehler, P.; Busso, L.; Cargnelli, M.; Choi, S.; Curceanu, C.; Enomoto, S.; Faso, D.; Fujioka, H.; Fujiwara, Y.; Fukuda, T.; Fukuda, Y.; Guaraldo, C.; Hashimoto, T.; Hayano, R. S.; Hiraiwa, T.; Iio, M.; Iliescu, M.; Inoue, K.; Ishikawa, T.; Ishimoto, S.; Ishiwatari, T.; Itahashi, K.; Iwai, M.; Iwasaki, M.; Kienle, P.; Kou, H.; Marton, J.; Matsuda, Y.; Mizoi, Y.; Morra, O.; Nagae, T.; Noumi, H.; Ohnishi, H.; Okada, S.; Outa, H.; Pietreanu, D.; Sada, Y.; Sakaguchi, A.; Sakuma, F.; Sato, M.; Sekimoto, M.; Sirghi, D.; Sirghi, F.; Suzuki, K.; Suzuki, S.; Suzuki, T.; Tatsuno, H.; Tokuda, M.; Tomono, D.; Toyoda, A.; Tsukada, K.; Widmann, E.; Yamazaki, T.; Yim, H.; Zmeskal, J.
2010-04-01
The J-PARC E15 experiment will be performed to search for the simplest kaonic nuclear bound state, K- pp, by the in-flight 3He(K-,n) reaction. The exclusive measurement can be performed by a simultaneous measurement of the missing mass using the primary neutron and the invariant mass via the expected decay, K- pp → Λp → pπ- p. In this report, an overview of the experiment and the preparation status are presented.
Direct Experimental Evidence of Exciton-Phonon Bound States in Carbon Nanotubes
Plentz, Flavio; Henrique B. Ribeiro; Jorio, Ado; Pimenta, Marcos A.; Strano, Michael S.
2005-01-01
We present direct experimental observation of exciton-phonon bound states in the photoluminescence excitation spectra of isolated single walled carbon nanotubes in aqueous suspension. The photoluminescence excitation spectra from several distinct single-walled carbon nanotubes show the presence of at least one sideband related to the tangential modes, lying {200 meV} above the main absorption/emission peak. Both the energy position and line shapes of the sidebands are in excellent agreement w...
Phase transitions of energy and wave functions and bound states in the continuum
Zhang, Xiao; Wei, Chaozhen; Liu, Yingming; Luo, Maokang
2016-04-01
This paper studies a particle subjected to an infinite potential well in the circumstance of a fractional dimensional Lévy path. To obtain analytic expression for the wave functions and energy levels, we introduce the fractional corresponding operator and a generalized de Moivre's theorem. Phase transitions of the energy and wave functions are found when the Lévy path dimension changes from integer to noninteger in nature. More importantly, we demonstrate the existence of stable bound states in the continuum in a simple potential. The results predict a phenomenon in which all bound states energy levels of the particle are continuous and the particle remains in bound states. This phenomenon can be demonstrated that this is a characteristic phenomenon of a fractional system. This phenomenon provides both an a priori criterion for theoretically describing an unknown quantum system with fractional derivatives and a sufficient condition for verifying the preparation of a fractional quantum system in experiment. Finally, we compare our results for fractional quantum systems with the existing results and explain the cause of the reported phenomenon.
From nonlocal gap solitary waves to bound states in periodic media
Akylas, T R; Yang, Jianke
2011-01-01
Solitary waves in one-dimensional periodic media are discussed employing the nonlinear Schr\\"odinger equation with a spatially periodic potential as a model. This equation admits two families of gap solitons that bifurcate from the edges of Bloch bands in the linear wave spectrum. These fundamental solitons may be positioned only at specific locations relative to the potential; otherwise, they become nonlocal owing to the presence of growing tails of exponentially-small amplitude with respect to the wave peak amplitude. Here, by matching the tails of such nonlocal solitary waves, higher-order locally confined gap solitons, or bound states, are constructed. Details are worked out for bound states comprising two nonlocal solitary waves in the presence of a sinusoidal potential. A countable set of bound-state families, characterized by the separation distance of the two solitary waves, is found, and each family features three distinct solution branches that bifurcate near Bloch-band edges at small, but finite, a...
Coherent-structure theory and bound-state formation in electrified falling films
Lin, Te-Sheng; Tseluiko, Dmitri; Blyth, Mark; Kalliadasis, Serafim
2015-11-01
We consider a perfectly conducting viscous liquid film flowing down an inclined wall and subjected to a normal electric filed. The electric field introduces a destabilizing non-local term in the long-wave evolution equation and the solutions may evolve into arrays of interacting pulses. We develop a weak-interaction theory for these pulses using elements from previous coherent-structure interaction theories we have developed. We show that the standard first-neighbor approximation is no longer valid and it is essential to take into account long-range interactions. We also develop numerical continuation techniques to explore bifurcation diagrams in systems possessing translational symmetry, including traveling waves and spatially varying time-periodic solutions. We find that each bound state bifurcates from the primary branch when continuing with respect to the domain size, and we then construct full bifurcation diagrams taking into account all the bound states. Finally, we compare the bound states for the long-wave evolution equation with the ones found in Stokes calculations and find excellent agreement.
Gluon bound state and asymptotic freedom derived from the Bethe--Salpeter equation
Fukamachi, Hitoshi; Nishino, Shogo; Shinohara, Toru
2016-01-01
In this paper we study the two-body bound states for gluons and ghosts in a massive Yang-Mills theory which is obtained by generalizing the ordinary massless Yang-Mills theory in a manifestly Lorentz covariant gauge. First, we give a systematic derivation of the coupled Bethe-Salpeter equations for gluons and ghosts by using the Cornwall-Jackiw-Tomboulis effective action of the composite operators within the framework of the path integral quantization. Then, we obtain the numerical solutions for the Bethe-Salpeter amplitude representing the simultaneous bound states of gluons and ghosts by solving the homogeneous Bethe-Salpeter equation in the ladder approximation. We study how the inclusion of ghosts affects the two-gluon bound states in the cases of the standing and running gauge coupling constant. Moreover, we show explicitly that the approximate solutions obtained for the gluon-gluon amplitude are consistent with the ultraviolet asymptotic freedom signaled by the negative $\\beta$ function.
Mapping trilobite state signatures in atomic hydrogen
Pérez-Ríos, Jesús; Greene, Chris H
2016-01-01
A few-body approach relying on static line broadening theory is developed to treat the spectroscopy of a single Rydberg excitation to a trilobite-like state immersed in a high density ultracold medium. The present theoretical framework implements the compact treatment of polyatomic Rydberg molecules by Eiles et al. [arXiv:1601.06881], allowing for an accurate treatment of a large number of perturbers within the Rydberg orbit. This system exhibits two unique spectral signatures: its lineshape depends on the Rydberg quantum number $n$ but, strikingly, is independent of the density of the medium, and it is characterized by sharply peaked features reflecting the oscillatory structure of the potential energy landscape.
Upper bound for SL-invariant entanglement measures of mixed states
Osterloh, Andreas
2016-05-01
An algorithm is proposed that serves to handle full-rank density matrices when coming from a lower-rank method to compute the convex roof. This is in order to calculate an upper bound for any polynomial SL-invariant multipartite entanglement measure E . This study exemplifies how this algorithm works based on a method for calculating convex roofs of rank-2 density matrices. It iteratively considers the decompositions of the density matrix into two states each, exploiting the knowledge for the rank-2 case. The algorithm is therefore quasiexact as far as the rank-2 case is concerned, and it also hints where it should include more states in the decomposition of the density matrix. Focusing on the measure of three-way entanglement of qubits (called three-tangle), I show the results the algorithm gives for two states, one of which is the Greenberger-Horne-Zeilinger-Werner (GHZ-W ) state, for which the exact convex roof is known. It overestimates the three-tangle in the state, thereby giving insight into the optimal decomposition the GHZ-W state has. As a proof of principle, I have run the algorithm for the three-tangle on the transverse quantum Ising model. I give qualitative and quantitative arguments why the convex roof should be close to the upper bound found here.
Measured Atomic Ground State Polarizabilities of 35 Metallic Elements
Indergaard, John; Ma, Lei; Zhang, Baiqian; Larkin, Ilia; Moro, Ramiro; de Heer, Walter
2015-03-01
Advanced pulsed cryogenic molecular beam electric deflection methods utilizing a position-sensitive mass spectrometer and 7.87 eV ionizing radiation were used to measure the polarizabilities of more than half of the metallic elements in the periodic table for the first time. These measurements increase the total number of experimentally obtained atomic polarizabilities from 23 to 57. Concurrent Stern-Gerlach deflection measurements verified the ground state condition of the measured atoms. Generating higher temperature beams allowed for the comparison of relative populations of the ground and excited states in order to extract the true temperature of the atomic beam, which followed the nominal temperature closely over a wide temperature range. Comparison of newly measured polarizabilities with state-of-the-art calculations exposes significant systematic and isolated discrepancies throughout the periodic table. Cluster Lab at Georgia Tech.
Some topological states in one-dimensional cold atomic systems
Energy Technology Data Exchange (ETDEWEB)
Mei, Feng; Zhang, Dan-Wei; Zhu, Shi-Liang, E-mail: slzhu@nju.edu.cn
2015-07-15
Ultracold atoms trapped in optical lattices nowadays have been widely used to mimic various models from condensed-matter physics. Recently, many great experimental progresses have been achieved for producing artificial magnetic field and spin–orbit coupling in cold atomic systems, which turn these systems into a new platform for simulating topological states. In this paper, we give a review focusing on quantum simulation of topologically protected soliton modes and topological insulators in one-dimensional cold atomic system. Firstly, the recent achievements towards quantum simulation of one-dimensional models with topological non-trivial states are reviewed, including the celebrated Jackiw–Rebbi model and Su–Schrieffer–Heeger model. Then, we will introduce a dimensional reduction method for systematically constructing high dimensional topological states in lower dimensional models and review its applications on simulating two-dimensional topological insulators in one-dimensional optical superlattices.
Novel properties of bound states of Klein-Gordon equation in gravitational field of massive point
International Nuclear Information System (INIS)
We are considering for the first time the solutions of Klein-Gordon equation in gravitational field of massive point source in general relativity (GR). We examine numerically the basic bounded quantum state and the next few states in the discrete spectrum for different values of the orbital momentum. A novel feature of the solutions under consideration is the essential dependence if their physical properties on the gravitational mass defect of the point source. Such mass defect was not introduced up to recently. Its variation yields a repulsion or an attraction of the quantum levels up to their quasi-crossing. (authors)
Introduction to Basis Light-Front Quantization Approach to QCD Bound State Problems
Li, Yang; Zhao, Xingbo; Maris, Pieter; Vary, James P
2013-01-01
Basis Light-Front Quantized Field Theory (BLFQ) is an $\\textit{ab intio}$ Hamiltonian approach that adopts light-cone gauge, light-front quantization and state-of-the-art many-body methods to solve non-perturbative quantum field theory problems. By a suitable choice of basis, BLFQ retains the underlying symmetries to the extent allowed within light-front coordinates. In this talk, we outline the scheme for applying BLFQ to QCD bound state problems. We adopt a 2D Harmonic Oscillator with 1D plane wave basis that corresponds to the AdS/QCD soft-wall solution. Exact treatment of the symmetries will be discussed.
International Nuclear Information System (INIS)
Security of a continuous-variable quantum key distribution protocol based on noisy coherent states and channel is analysed. Assuming that the noise of coherent states is induced by Fred, a neutral party relative to others, we prove that the prepare-and-measurement scheme (P and M) and entanglement-based scheme (E-B) are equivalent. Then, we show that this protocol is secure against Gaussian collective attacks even if the channel is lossy and noisy, and, further, a lower bound to the secure key rate is derived.
Formation Mechanism of Guided Resonances and Bound States in the Continuum in Photonic Crystal Slabs
Gao, Xingwei; Zhen, Bo; Lin, Xiao; Joannopoulos, John D; Soljačić, Marin; Chen, Hongsheng
2016-01-01
We develop a formalism, based on the mode expansion method, to describe the guided resonances and bound states in the continuum (BICs) in photonic crystal slabs with one-dimensional periodicity. This approach provides analytic insights to the formation mechanisms of these states: the guided resonances arise from the transverse Fabry-P\\'erot condition, and the divergence of the resonance lifetimes at the BICs is explained by a destructive interference of radiation from different propagating components inside the slab. We show BICs at the center and on the edge of the Brillouin zone protected by symmetry, as well as BICs at generic wave vectors not protected by symmetry.
Two-body bound states ampersand the Bethe-Salpeter equation
International Nuclear Information System (INIS)
The Bethe-Salpeter formalism is used to study two-body bound states within a scalar theory: two scalar fields interacting via the exchange of a third massless scalar field. The Schwinger-Dyson equation is derived using functional and diagrammatic techniques, and the Bethe-Salpeter equation is obtained in an analogous way, showing it to be a two-particle generalization of the Schwinger-Dyson equation. The authors also present a numerical method for solving the Bethe-Salpeter equation without three-dimensional reduction. The ground and first excited state masses and wavefunctions are computed within the ladder approximation and space-like form factors are calculated
Excited hadrons and the analytical structure of bound-state interaction kernels
El-Bennich, Bruno; Rojas, Eduardo; Serna, Fernando E
2016-01-01
We highlight Hermiticity issues in bound-state equations whose kernels are subject to a highly asymmetric mass and momentum distribution and whose eigenvalue spectrum becomes complex for radially excited states. We trace back the presence of imaginary components in the eigenvalues and wave functions to truncation artifacts and suggest how they can be eliminated in the case of charmed mesons. The solutions of the gap equation in the complex plane, which play a crucial role in the analytic structure of the Bethe-Salpeter kernel, are discussed for several interaction models and qualitatively and quantitatively compared to analytic continuations by means of complex-conjugate pole models fitted to real solutions.
Heralded atomic-ensemble quantum memory for photon polarization states
International Nuclear Information System (INIS)
We describe the mapping of quantum states between single photons and an atomic ensemble. In particular, we demonstrate a heralded quantum memory based on the mapping of a photon polarization state onto a single collective-spin excitation (magnon) shared between two atomic ensembles. The polarization fidelity above 90(2)% for any input polarization far exceeds the classical limit of 2/3. The process also constitutes a quantum non-destructive probe that detects and regenerates a photon without measuring its polarization.
Directory of Open Access Journals (Sweden)
L Michel Espinoza-Fonseca
Full Text Available We have performed microsecond molecular dynamics (MD simulations to characterize the structural dynamics of cation-bound E1 intermediate states of the calcium pump (sarcoendoplasmic reticulum Ca²⁺-ATPase, SERCA in atomic detail, including a lipid bilayer with aqueous solution on both sides. X-ray crystallography with 40 mM Mg²⁺ in the absence of Ca²⁺ has shown that SERCA adopts an E1 structure with transmembrane Ca²⁺-binding sites I and II exposed to the cytosol, stabilized by a single Mg²⁺ bound to a hybrid binding site I'. This Mg²⁺-bound E1 intermediate state, designated E1•Mg²⁺, is proposed to constitute a functional SERCA intermediate that catalyzes the transition from E2 to E1•2Ca²⁺ by facilitating H⁺/Ca²⁺ exchange. To test this hypothesis, we performed two independent MD simulations based on the E1•Mg²⁺ crystal structure, starting in the presence or absence of initially-bound Mg²⁺. Both simulations were performed for 1 µs in a solution containing 100 mM K⁺ and 5 mM Mg²⁺ in the absence of Ca²⁺, mimicking muscle cytosol during relaxation. In the presence of initially-bound Mg²⁺, SERCA site I' maintained Mg²⁺ binding during the entire MD trajectory, and the cytosolic headpiece maintained a semi-open structure. In the absence of initially-bound Mg²⁺, two K⁺ ions rapidly bound to sites I and I' and stayed loosely bound during most of the simulation, while the cytosolic headpiece shifted gradually to a more open structure. Thus MD simulations predict that both E1•Mg²⁺ and E•2K+ intermediate states of SERCA are populated in solution in the absence of Ca²⁺, with the more open 2K+-bound state being more abundant at physiological ion concentrations. We propose that the E1•2K⁺ state acts as a functional intermediate that facilitates the E2 to E1•2Ca²⁺ transition through two mechanisms: by pre-organizing transport sites for Ca²⁺ binding, and by partially opening the
Bound states induced giant oscillations of the conductance in the quantum Hall regime.
Kadigrobov, A M; Fistul, M V
2016-06-29
We theoretically studied the quasiparticle transport in a 2D electron gas biased in the quantum Hall regime and in the presence of a lateral potential barrier. The lateral junction hosts the specific magnetic field dependent quasiparticle states highly localized in the transverse direction. The quantum tunnelling across the barrier provides a complex bands structure of a one-dimensional energy spectrum of these bound states, [Formula: see text], where p y is the electron momentum in the longitudinal direction y. Such a spectrum manifests itself by a large number of peaks and drops in the dependence of the magnetic edge states transmission coefficient D(E ) on the electron energy E. E.g. the high value of D occurs as soon as the electron energy E reaches gaps in the spectrum. These peaks and drops of D(E) result in giant oscillations of the transverse conductance G x with the magnetic field and/or the transport voltage. Our theoretical analysis, based on the coherent macroscopic quantum superposition of the bound states and the magnetic edge states propagating along the system boundaries, is in a good accord with the experimental observations found in Kang et al (2000 Lett. Nat. 403 59). PMID:27166511
Bound states induced giant oscillations of the conductance in the quantum Hall regime
Kadigrobov, A. M.; Fistul, M. V.
2016-06-01
We theoretically studied the quasiparticle transport in a 2D electron gas biased in the quantum Hall regime and in the presence of a lateral potential barrier. The lateral junction hosts the specific magnetic field dependent quasiparticle states highly localized in the transverse direction. The quantum tunnelling across the barrier provides a complex bands structure of a one-dimensional energy spectrum of these bound states, {εn}≤ft( {{p}y}\\right) , where p y is the electron momentum in the longitudinal direction y. Such a spectrum manifests itself by a large number of peaks and drops in the dependence of the magnetic edge states transmission coefficient D(E ) on the electron energy E. E.g. the high value of D occurs as soon as the electron energy E reaches gaps in the spectrum. These peaks and drops of D(E) result in giant oscillations of the transverse conductance G x with the magnetic field and/or the transport voltage. Our theoretical analysis, based on the coherent macroscopic quantum superposition of the bound states and the magnetic edge states propagating along the system boundaries, is in a good accord with the experimental observations found in Kang et al (2000 Lett. Nat. 403 59)
Signatures of Majorana bound states in one-dimensional topological superconductors
International Nuclear Information System (INIS)
Topological states of matter have fascinated condensed matter physicists for the past three decades. Famous examples include the integer and fractional quantum Hall states exhibiting a spectacular conductance quantization as well as topological insulators in two and three dimensions featuring gapless Dirac fermions at the boundary. Very recently, novel topological phases in superconductors have been subject of intense experimental and theoretical investigation. One-dimensional topological superconductors are particularly intriguing as they host exotic Majorana end states. These are zero-energy bound states with nonabelian exchange statistics potentially useful for topologically protected quantum computing. Recent theoretical and experimental advances have put the realization of Majorana states within reach of current measurement techniques. In this thesis we investigate signatures of Majorana bound states in realistic experiments aiming to improve the theoretical understanding of ongoing experimental efforts and to design novel measurement schemes, which exhibit convincing signatures of Majoranas. In particular we account for nonideal experimental conditions which can lead to qualitatively new features. Possible signatures of Majoranas can be accessed in the Josephson current through a weak link between two topological superconductors although the signatures in the dc Josephson effect are typically obscured by inevitable quasiparticle relaxation in the superconductor. Here we propose a measurement scheme in mesoscopic superconducting rings, where Majorana signatures persist even for infinitely fast relaxation. In a separate project we outline an alternative to the standard Josephson experiment in topological superconductors based on quantum wires. We delineate how Majoranas can be detected, when the Josephson current is induced by noncollinear magnetic fields applied to the two banks of the junction instead of a superconducting phase difference. Another important
Bound states of fermions in external and self-consistent fields
International Nuclear Information System (INIS)
The properties of spin-1/2 fields in strong external potentials are investigated in order to determine what happens to the electron orbitals as the charge of the nucleus is increased without bounds. Strongly interacting quantum fields are investigated, motivated by the picture of quark bags, in which light quanta provide all the internal structure. Several general properties of the solutions of fermion fields interacting with meson fields are considered with the help of field theory analogues of virial relations. A description of the algorithm used to generate examples of the self-consistent solutions in three-space dimensions is also presented. Since it is difficult to associate the properties of strongly bound states with those of weakly interacting quasi-particles, several options for the candidates for the relevant interaction are considered. The present investigations deal only with Abelian fields. (Auth.)
Thermoelectric signatures of a Majorana bound state coupled to a quantum dot
International Nuclear Information System (INIS)
We theoretically investigate the possibility to use thermolectric measurements to detect Majorana bound states and to investigate their coupling to a dissipative environment. The particle–hole symmetry of Majorana states would normally lead to a vanishing Seebeck coefficient, i.e. a vanishing open-circuit voltage resulting from a temperature gradient. We discuss how coupling to a quantum dot with a gate-controlled energy level breaks particle–hole symmetry in a tunable manner. The resulting gate-dependent Seebeck coefficient provides a new way to evidence the existence of Majorana states, which can be combined with conventional tunnel spectroscopy in the same setup. Furthermore, the thermoelectric properties rely on the ability of the quantum dot–Majorana system to sense the temperature of the bulk superconductor and can be used to extract information about the dissipative decay of Majorana states, which is crucial for quantum information applications. (paper)
Stability of Majorana vortex bound states on the surface of superconducting topological insulators
Zhang, Junyi; Cano, Jennifer; Neupert, Titus
Fu and Kane showed that superconductivity induced on the surface of a 3D topological insulator results in isolated Majorana bound states that appear in the cores of vortices. Many efforts to realize this idea are based on proximity-induced superconducting order in a heterostructure. Recently, superconductivity has been observed in PbTaSe2, which has the band topology of a topological insulator with Dirac cone surface states. Hence, it nourishes the vision of realizing the Fu and Kane proposal in a stoichiometric material without the need for doping or fabricating heterostructures. Motivated by this possibility, we give a comprehensive analysis of stability and localization properties of the vortex Majorana modes in such a topological superconducting material. In particular, we address the experimentally relevant questions regarding (i) the energy separation between the vortex bound and excited states, (ii) the dependence of the hybridization between Majorana modes from opposite surfaces on the thickness of a thin-film sample, (iii) the influence of the bulk superconducting pockets on the Majorana states.
Dependence of internal conversion coefficient on atom state
International Nuclear Information System (INIS)
Calculations of the internal conversion coefficient (ICC) for the (Fe) atom d-shell containing 6 electrons at a maximum occupation number of 10 are presented. In the relativistic approach use is made of the multiconfiguration approximation, which makes it possible to take account of the intermediate coupling in nonfilled shells. The energy matrix has been calculated in the determinantal basis of these configurations and then diagonalized. Radial single-electron wave functions have been calculated by the relativistic method of the Hartry-Fock-Dirac self consistent field. Occupational numbers of Fe d-subshells for the 5D basic multiplet states are given. Atom electrical and magnetic ICC are analyzed. Electrical ICC are practically the same for all the levels. The electrical ICC calculated for one electron does not depend on the spin orientation. Magnetic ICC show considerable dependence of the atom state. Within the multiplet limits the ICC change smoothly, decreasing for higher levels
States of antimony and tin atoms in lead chalcogenides
International Nuclear Information System (INIS)
It is shown by Mössbauer spectroscopy of the 119Sb(119mSn) isotope that impurity antimony atoms in PbS, PbSe, and PbTe lattices are distributed between cation and anion sublattices. In n-type samples, the greatest part of antimony is located in the anion sublattice; in hole ones, in the cation sublattice. The tin atoms formed as a result of radioactive decay of 119Sb (antisite state) are electrically inactive in the anion sub-lattice of PbS and PbSe, while, in the cation sublattice, they form donor U− centers. Electron exchange between the neutral and doubly ionized tin U− centers via the allowed band states is observed. The tin atoms formed after radioactive decay of 119Sb are electrically inactive in the anion and cation sublattices of PbTe.
Entangling qubit registers via many-body states of ultracold atoms
Melko, R. G.; Herdman, C. M.; Iouchtchenko, D.; Roy, P.-N.; Del Maestro, A.
2016-04-01
Inspired by the experimental measurement of the Rényi entanglement entropy in a lattice of ultracold atoms by Islam et al. [Nature (London) 528, 77 (2015), 10.1038/nature15750], we propose a method to entangle two spatially separated qubits using the quantum many-body state as a resource. Through local operations accessible in an experiment, entanglement is transferred to a qubit register from atoms at the ends of a one-dimensional chain. We compute the operational entanglement, which bounds the entanglement physically transferable from the many-body resource to the register, and discuss a protocol for its experimental measurement. Finally, we explore measures for the amount of entanglement available in the register after transfer, suitable for use in quantum information applications.
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.
Coherent excitation of a single atom to a Rydberg state
DEFF Research Database (Denmark)
Miroshnychenko, Yevhen; Gaëtan, Alpha; Evellin, Charles;
2010-01-01
We present the coherent excitation of a single Rubidium atom to the Rydberg state 58d3/2 using a two-photon transition. The experimental setup is described in detail, as are experimental techniques and procedures. The coherence of the excitation is revealed by observing Rabi oscillations between...
Ground state wave function and energy of the lithium atom
Puchalski, Mariusz; Pachucki, Krzysztof
2006-01-01
Highly accurate nonrelativistic ground-state wave function and energy of the lithium atom is obtained in the Hylleraas basis set. The leading relativistic corrections,as represented by Breit-Pauli Hamiltonian, are obtained in fair agreement with the former results. The calculational method is based on the analytical evaluation of Hylleraas integrals with the help of recursion relations.
Electronic interaction anisotropy between atoms in arbitrary angular momentum states
Krems, R.V.; Groenenboom, G.C.; Dalgarno, A.
2004-01-01
A general tensorial expansion for the interaction potential between two atoms in arbitrary angular momentum states is derived and the relations between the expansion coefficients and the Born-Oppenheimer potentials of the diatomic molecule are obtained. It is demonstrated that a complete expansion o
Measured atomic ground-state polarizabilities of 35 metallic elements
Ma, Lei; Indergaard, John; Zhang, Baiqian; Larkin, Ilia; Moro, Ramiro; de Heer, Walt A.
2015-01-01
Advanced pulsed cryogenic molecular-beam electric deflection methods involving position-sensitive mass spectrometry and 7.87-eV ionizing radiation were used to measure the polarizabilities of more than half of the metallic elements in the Periodic Table. Concurrent Stern-Gerlach deflection measurements verified the ground-state condition of the measured atoms. Comparison with state-of-the-art calculations exposes significant systematic and isolated discrepancies throughout the Periodic Table.
Conditional preparation of arbitrary superpositions of atomic Dicke states
Czech Academy of Sciences Publication Activity Database
Lemr, Karel; Fiurášek, J.
2009-01-01
Roč. 79, č. 4 (2009), 043808/1-043808/9. ISSN 1050-2947 R&D Projects: GA MŠk(CZ) 1M06002 Grant ostatní: 7 FP FET COMPAS(XE) 212008 Institutional research plan: CEZ:AV0Z10100522 Keywords : atomic Dicke states * highly nonclassical states Subject RIV: BH - Optics, Masers, Lasers Impact factor: 2.866, year: 2009
Institute of Scientific and Technical Information of China (English)
CHEN Chang-Yong; LI Shao-Hua
2007-01-01
A scheme for approximately and conditionally teleporting an unknown atomic-entangled state in cavity QED is proposed.It is the novel extension of the scheme of [Phys.Rev.A 69 (2004) 064302],where the state to be teleported is an unknown atomic state and where only a time point of system evolution and the corresponding fidelity implementing the teleportation are given.In fact,there exists multi-time points and the corresponding fidclities,which are shown in this paper and then are used to realize the approximate and conditional teleportation of the unknown atomic-entangled state.Naturally,our scheme does not involve the Bell-state measurement or an additional atom,which is required in the Bell-state measurement,only requiring one single-mode cavity.The scheme may be generalized to not only the teleportation of the cavity-mode-entangled-state by means of a single atom but also the teleportation of the unknown trapped-ion-entangled-state in a linear ion trap and the teleportation of the multi-atomic entangled states included in generalized GHZ states.
International Nuclear Information System (INIS)
A scheme for approximately and conditionally teleporting an unknown atomic-entangled state in cavity QED is proposed. It is the novel extension of the scheme of [Phys. Rev. A 69 (2004) 064302], where the state to be teleported is an unknown atomic state and where only a time point of system evolution and the corresponding fidelity implementing the teleportation are given. In fact, there exists multi-time points and the corresponding fidelities, which are shown in this paper and then are used to realize the approximate and conditional teleportation of the unknown atomic-entangled state. Naturally, our scheme does not involve the Bell-state measurement or an additional atom, which is required in the Bell-state measurement, only requiring one single-mode cavity. The scheme may be generalized to not only the teleportation of the cavity-mode-entangled-state by means of a single atom but also the teleportation of the unknown trapped-ion-entangled-state in a linear ion trap and the teleportation of the multi-atomic entangled states included in generalized GHZ states.
Bichromatic State-insensitive Trapping of Caesium Atoms
Metbulut, M M
2015-01-01
State-insensitive dipole trapping of multilevel atoms can be achieved by an appropriate choice of the wavelength of the trapping laser, so that the interaction with the different transitions results in equal AC Stark shifts for the ground and excited states of interest. However this approach is severely limited by the availability of coherent sources at the required wavelength and of appropriate power. This work investigates state-insensitive trapping of caesium atoms for which the required wavelength of 935.6 nm is inconvenient in terms of experimental realization. Bichromatic state-insensitive trapping is proposed to overcome the lack of suitable laser sources. We first consider pairs of laser wavelengths in the ratio 1:2 and 1:3, as obtained via second- and third- harmonic generation. We found that the wavelength combinations 931.8-1863.6 nm and 927.5-2782.5 nm are suitable for state-insensitive trapping of caesium atoms. In addition, we examine bichromatic state-insensitive trapping produced by pairs of l...
Bichromatic state-insensitive trapping of caesium atoms
Metbulut, M. M.; Renzoni, F.
2015-12-01
State-insensitive dipole trapping of multilevel atoms can be achieved by an appropriate choice of the wavelength of the trapping laser, so that the interaction with the different transitions results in equal AC Stark shifts for the ground and excited states of interest. However this approach is severely limited by the availability of coherent sources at the required wavelength and of appropriate power. This work investigates state-insensitive trapping of caesium atoms for which the required wavelength of 935.6 nm is inconvenient in terms of experimental realization. Bichromatic state-insensitive trapping is proposed to overcome the lack of suitable laser sources. We first consider pairs of laser wavelengths in the ratio 1:2 and 1:3, as obtained via second- and third- harmonic generation. We found that the wavelength combinations 931.8-1863.6 nm and 927.5-2782.5 nm are suitable for state-insensitive trapping of caesium atoms. In addition, we examine bichromatic state-insensitive trapping produced by pairs of laser wavelengths corresponding to currently available high power lasers. These wavelength pairs were found to be in the range of 585-588 nm and 623-629 for one laser and 1064-1080 nm for the other.
de Lara-Castells, María Pilar; Mitrushchenkov, Alexander O
2015-11-01
The interaction potential of molecular hydrogen physisorbed on a graphene sheet is evaluated using the ab initio-based periodic dlDF+Das scheme and its accuracy is assessed by comparing the nuclear bound-state energies supported by the H2(D2/HD)/graphite potentials with the experimental energies. The periodic dlDF+Das treatment uses DFT-based symmetry-adapted perturbation theory on surface cluster models to extract the dispersion contribution to the interaction whereas periodic dispersionless density functional (dlDF) calculations are performed to determine the dispersion-free counterpart. It is shown that the H2/graphene interaction is effectively two-dimensional (2D), with the distance from the molecule center-of-mass to the surface plane and the angle between the diatomic axis and the surface normal as the relevant degrees of freedom. The global potential minimum is found at the orthogonal orientation of the molecule with respect to the surface plane, with an equilibrium distance of 3.17 Å and a binding energy of -51.9 meV. The comparison of the binding energies shows an important improvement of our approach over the vdW-corrected DFT schemes when we are dealing with the very weak H2/surface interaction. Next, the 2D nuclear bound-state energies are calculated numerically. As a cross-validation of the interaction potential, the bound states are also determined for molecular hydrogen on the graphite surface (represented as an assembly of graphene sheets). With the largest absolute deviation being 1.7 meV, the theoretical and experimental energy levels compare very favorably. PMID:26479965
Formation of heavy-Rydberg ion-pair states in Rydberg atom collisions with attaching targets
Wang, Changhao; Kelley, Michael; Buathong, Sitti; Dunning, F. Barry
2014-05-01
Electron transfer in collisions between K(np)Rydberg atoms and electron attaching molecules can lead to formation of heavy-Rydberg ion-pair states comprising a weakly-bound positive-negative ion pair orbiting at large internuclear separations. In the present work ion-pair states are created in a small collision cell and allowed to exit into an analysis region where their binding energy and velocity distributions are determined with the aid of electric-field-induced dissociation and a position sensitive detector. Ion pair production is analyzed using a Monte Carlo collision code that models both the initial Rydberg electron capture and the subsequent behavior of the product ion pair. The data demonstrate that collisions with SF6 and CCl4 lead to formation of long-lived ion pair states with a broad distribution of binding energies whose velocity distribution is strongly peaked in the forward direction. Research supported by the Robert A. Welch Foundation.
Effect of the velocity-dependent potentials on the bound state energy eigenvalues
International Nuclear Information System (INIS)
We investigate the effect of isotropic velocity-dependent potentials on the bound state energy eigenvalues for the first time for any quantum states of the Coulomb and harmonic oscillator potentials within the framework of the asymptotic iteration method. When the velocity-dependent term is selected as a constant parameter ρ0, we present that the energy eigenvalues can be obtained analytically for both Coulomb and harmonic oscillator potentials. However, when the velocity-dependent term is considered as a harmonic oscillator type ρ0r2, taking the velocity-dependent term as a perturbation, we present how to obtain the energy eigenvalues of the Coulomb and harmonic oscillator potentials for any n and ℓ quantum states by using perturbation expansion and numerical calculations in the asymptotic iteration method procedure. (authors)
Effect of the Velocity-Dependent Potentials on the Bound State Energy Eigenvalues
International Nuclear Information System (INIS)
We investigate the effect of isotropic velocity-dependent potentials on the bound state energy eigenvalues for the first time for any quantum states of the Coulomb and harmonic oscillator potentials within the framework of the asymptotic iteration method. When the velocity-dependent term is selected as a constant parameter ρ0, we present that the energy eigenvalues can be obtained analytically for both Coulomb and harmonic oscillator potentials. However, when the velocity-dependent term is considered as a harmonic oscillator type ρ0r2, taking the velocity-dependent term as a perturbation, we present how to obtain the energy eigenvalues of the Coulomb and harmonic oscillator potentials for any n and l quantum states by using perturbation expansion and numerical calculations in the asymptotic iteration method procedure. (general)
Khan, Md Abdul
2015-01-01
Bound state properties of few single and double-$\\Lambda$ hypernuclei is critically examined in the framework of core-$\\Lambda$ and core+$\\Lambda+\\Lambda$ few-body model applying hyperspherical harmonics expansion method (HHEM). The $\\Lambda\\Lambda$ potential is chosen phenomenologically while the core-$\\Lambda$ potential is obtained by folding a phenomenological $\\Lambda N$ interaction into the density distribution of the core. The depth of the effective $\\Lambda N$ potential is adjusted to reproduce the experimental data for the core-$\\Lambda$ subsystem. The three-body Schr\\"odinger equation is solved by hyperspherical adiabatic approximation (HAA) to get the ground state energy and wave function. The ground state wavefunction is used to construct the supersymmetric partner potential following prescription of supersymmetric quantum mechanics (SSQM) algebra. The newly constructed supersymmetric partner potential is used to solve the three-body Schr\\"odinger equation to get the energy and wavefunction for the...
Statistical Production of Antikaon Nuclear Bound States in Heavy Ion Collisions
Andronic, A; Redlich, K
2006-01-01
Recently it was shown that the strongly attractive antikaon--nucleon potential can result in the formation of the antikaon nuclear bound states. We discuss the formation of such states as possible residues in heavy ion collisions. In this context, we calculate the excitation functions of single- and double-K- clusters in terms of the statistical thermal model. We show that, if such objects indeed exist, then, in heavy ion collisions, the single-K- clusters are most abundantly produced at present SIS energies, while the double-$K^-$ clusters show a pronounced maximum yield in the energy domain of the future accelerator at GSI. This is a direct consequence of: i) the baryonic dominance in low energy heavy ion collisions and the large baryonic content of the antikaonic bound states; ii) the strong energy dependence of strangeness production at low energies. The production yields of double-strange clusters is compared with that of double strange baryons. It is shown that at SIS energies there is a linear scaling ...
Bound and continuum states of molecular anions C2H- and C3N-
Harrison, Stephen; Tennyson, Jonathan
2011-02-01
Recently a number of molecular anions, closed-shell linear carbon chains of the form CnH- and CnN-, have been detected in space. The molecules C2H- and C3N- are investigated by using the R-matrix method to consider electron scattering from the corresponding neutral targets. Initial target calculations are conducted and refined in order to produce target state characteristics similar to the experimental data. A number of different scattering models are tested including static exchange and close-coupling models, and the use of Hartree-Fock or natural orbitals in the close-coupling calculations. The calculations concentrate on bound and resonances states for the anions as well as eigenphase sums, elastic cross-sections and electronic excitation cross-sections for electron collisions with the neutral. It is found that electronic resonances are all too high in energy to be important for anion formation in the interstellar medium. However, C3N-, unlike C2H-, supports a number of very weakly bound excited states, which may well provide the route to electron attachment for this system.
Studies of K-absorption on light nuclei and the search for bound nuclear kaonic states
International Nuclear Information System (INIS)
The available experimental data on K-absorption on nuclei are rather old and scarce: they are not enough to understand the possible formation of aggregates of nucleons bound together by a kaon, known as 'Bound Kaonic Nuclear States'. The existence of such structures, suggested by a few theoretical models, has not been experimentally ascertained yet. To be observed, their width should be less than their binding energy. A possible decay channel for such states is the non mesonic one, leading to hyperon-nucleon (or light nuclei) final states. Therefore, experimental investigations of possible signatures are mainly based on the analysis of hyperon-nucleon(s) correlations (for instance, of Λp(d,t) pairs) and of invariant mass spectra. Complementary information may also be gathered from missing mass distributions. Recent experiments revived, with much larger statistics, the study of K-A absorption in light nuclei: namely, KEK-E549 studied the K-interactions on 4He, while FINUDA at DAΦNE collected a large statistics on K-6,7Li, K-9Be and K-12C. The experimental results obtained so far by the various experiments studying the K-absorption in nuclei are here summarized.
Spectroscopic factors for bound s-wave states derived from neutron scattering lengths
International Nuclear Information System (INIS)
A simple and model-independent method is described to derive neutron single-particle spectroscopic factors of bound s-wave states in A+1Z = AZ circle-times n nuclei from neutron scattering lengths. Spectroscopic factors for the nuclei 13C, 14C, 16N, 17O, 19O, 23Ne, 37Ar, and 41Ar are compared to results derived from transfer experiments using the well-known disorted wave Born analysis and to shell model calculations. The scattering length of 14C is calculated from the 15Cg.s. spectroscopic factor. copyright 1997 The American Physical Society
Bound states and threshold resonances in quantum wires with circular bends
International Nuclear Information System (INIS)
We study the solutions to the wave equation in a two-dimensional tube of unit width comprised of two straight regions connected by a region of constant curvature. We introduce a numerical method which permits high accuracy at high curvature. We determine the bound state energies as well as the transmission and reflection matrices T and R and focus on the nature of the resonances that occur in the vicinity of channel thresholds. We explore the dependence of these solutions on the curvature of the tube and angle of the bend and discuss several limiting cases where our numerical results confirm analytic predictions. copyright 1996 The American Physical Society
Optical signatures of states bound to vacancy defects in monolayer MoS$_2$
Erementchouk, Mikhail; Khan, M A; Leuenberger, Michael N.
2015-01-01
We show that pristine MoS$_2$ single layer (SL) exhibits two bandgaps $E_{g\\parallel}=1.9$ eV and $E_{g\\perp}=3.2$ eV for the optical in-plane and out-of-plane susceptibilities $\\chi_\\parallel$ and $\\chi_\\perp$, respectively. In particular, we show that odd states bound to vacancy defects (VDs) lead to resonances in $\\chi_\\perp$ inside $E_{g\\perp}$ in MoS$_2$ SL with VDs. We use density functional theory, the tight-binding model, and the Dirac equation to study MoS$_2$ SL with three types of ...
Bound states of massive fermions in the Aharonov--Bohm-like fields
Khalilov, V. R.
2014-01-01
Bound states of massive fermions in the Aharonov-Bohm like fields have analytically been studied. The Hamiltonians with the Aharonov--Bohm like potentials are essentially singular and therefore require specification of a one-parameter self-adjoint extension. We construct self-adjoint Dirac Hamiltonians with the Aharonov-Bohm (AB) potential in 2+1 dimensions that are specified by boundary conditions at the origin. It is of interest that for some range of extension parameter the AB potential ca...
Tube of (Circle F, D0, D2) Bound State in Melvin Background
Huang, Wung-Hong
2004-01-01
By using the Born-Infeld action we show that the $m$ circular fundamental strings, $n$ D2-branes and $k$ D0-branes could become a tubular bound state which is prevented from collapsing by the magnetic force in the Melvin background. However, if the ratio $m/n$ is larger then a critical value the tube will become unstable and collapse to zero radius. We make analyses to find the critical value and tube radius therein. The tube configurations we found are different from the well known tubular b...
Hannestad, Steen
2005-01-01
Cosmology at present provides the nominally strongest constraint on the masses of standard model neutrinos. However, this constraint extremely dependent on the nature of the dark energy component of the Universe. When the dark energy equation of state parameter is taken as a free (but constant) parameter, the neutrino mass bound is sum m_nu < 1.48 eV (95% C.L.), compared with sum m_nu < 0.65 eV (95% C.L.) in the standard model where the dark energy is in the form of a cosmological constant. T...
The beauty of impurities: Two revivals of Friedel's virtual bound-state concept
Georges, Antoine
2016-03-01
Jacques Friedel pioneered the theoretical study of impurities and magnetic impurities in metals. He discovered Friedel oscillations, introduced the concept of virtual bound-state, and demonstrated that the charge on the impurity is related to the scattering phase-shift at the Fermi level (Friedel sum-rule). After a brief review of some of these concepts, I describe how they proved useful in two new contexts. The first one concerns the Coulomb blockade in quantum dots, and its suppression by the Kondo effect. The second one is the dynamical mean-field theory of strong electronic correlations. xml:lang="fr"
Search for the η-mesic Helium bound state with the WASA-at-COSY facility
Skurzok, Magdalena; Krzemień, Wojciech; Rundel, Oleksandr; Moskal, Pawel
2016-05-01
We performed a search for 4He-η bound state with high statistics and high acceptance with the WASA-at-COSY facility using a ramped beam technique. The signature of η-mesic nuclei is searched for in dd → 3Henπ0 and dd → 3Hepπ- reactions by the measurement of the excitation functions in the vicinity of the η production threshold. This paper presents the experimental method and the preliminary results of the data analysis for dd → 3Henπ0 process.
Search for the eta-mesic Helium bound state with the WASA-at-COSY facility
Skurzok, M; Rundel, O; Moskal, P
2015-01-01
We performed a search for 4He-eta bound state with high statistics and high acceptance with the WASA-at-COSY facility using a ramped beam technique. The signature of eta-mesic nuclei is searched for in dd -> 3Henpi0 and dd -> 3Heppi- reactions by the measurement of the excitation functions in the vicinity of the {\\eta} production threshold. This paper presents the experimental method and the preliminary results of the data analysis for dd -> 3Henpi0 process.
Quantum entanglement of charges in bound states with finite-size dyons
International Nuclear Information System (INIS)
We show that the presence of finite-size monopoles can lead to a number of interesting physical processes involving quantum entanglement of charges. Taking as a model the classical solution of the N=2 SU(2) Yang-Mills theory, we study interaction between dyons and scalar particles in the adjoint and fundamental representation. We find that there are bound states of scalars and dyons, which, remarkably, are always an entangled configuration of the form vertical bar ψ> = vertical bar dyon+> vertical bar scalar-> ± vertical bar dyon-> vertical bar scalar+>. We determine the energy levels and the wave functions and also discuss their stability. (author)
Monopole-fermion and dyon-fermion bound states. Pt. 5
International Nuclear Information System (INIS)
We present explicit, approximate, remarkably precise results for the Kazama-Yang hamiltonian, which describes a Dirac monopole interacting with a spin-1/2 fermion that has an extra magnetic moment. The results are valid for bound states of angular momentum j >= Zvertical strokeegvertical stroke+1/2, where the radial wave functions are determined by four coupled differential equations. These equations have been solved analytically for M - E << M, which is a limit of considerable practical interest. Binding energies and wave functions are given. (orig.)
Electric dipole transition rates of the bound states of the b bar b system
International Nuclear Information System (INIS)
We calculate the E1 decay rates of the bound states of the b bar b system in the nonsingular potential model of Gupta, Repko, and Suchyta (GRS) and compare them with the recent experimental results. We get predictions somewhat different from the original GRS results and overall these new results are in better agreement with experiment. We point out the importance of including both the relativistic corrections to the wave function and the finite-size corrections to the E1 decay rates, especially for transitions which involve a change of more than one unit in the radial quantum number
Computation of Quantum Bound States on a Singly Punctured Two-Torus
International Nuclear Information System (INIS)
We study a quantum mechanical system on a singly punctured two-torus with bound states described by the Maass waveforms which are eigenfunctions of the hyperbolic Laplace—Beltrami operator. Since the discrete eigenvalues of the Maass cusp form are not known analytically, they are solved numerically using an adapted algorithm of Hejhal and Then to compute Maass cusp forms on the punctured two-torus. We report on the computational results of the lower lying eigenvalues for the punctured two-torus and find that they are doubly-degenerate. We also visualize the eigenstates of selected eigenvalues using GridMathematica