Classical relativistic spinning particle with anomalous magnetic moment: The precession of spin

International Nuclear Information System (INIS)

Barut, A.O.; Cruz, M.G.

1993-05-01

The theory of classical relativistic spinning particles with c-number internal spinor variables, modelling accurately the Dirac electron, is generalized to particles with anomalous magnetic moments. The equations of motion are derived and the problem of spin precession is discussed and compared with other theories of spin. (author). 32 refs

Spin and orbital moments in actinide compounds

DEFF Research Database (Denmark)

Lebech, B.; Wulff, M.; Lander, G.H.

1991-01-01

The extended spatial distribution of both the transition-metal 3d electrons and the actinide 5f electrons results in a strong interaction between these electron states when the relevant elements are alloyed. A particular interesting feature of this hybridization, which is predicted by single...... experiments designed to determine the magnetic moments at the actinide and transition-metal sublattice sites in compounds such as UFe2, NpCo2, and PuFe2 and to separate the spin and orbital components at the actinide sites. The results show, indeed, that the ratio of the orbital to spin moment is reduced...

High-order moments of spin-orbit energy in a multielectron configuration

Science.gov (United States)

Na, Xieyu; Poirier, M.

2016-07-01

In order to analyze the energy-level distribution in complex ions such as those found in warm dense plasmas, this paper provides values for high-order moments of the spin-orbit energy in a multielectron configuration. Using second-quantization results and standard angular algebra or fully analytical expressions, explicit values are given for moments up to 10th order for the spin-orbit energy. Two analytical methods are proposed, using the uncoupled or coupled orbital and spin angular momenta. The case of multiple open subshells is considered with the help of cumulants. The proposed expressions for spin-orbit energy moments are compared to numerical computations from Cowan's code and agree with them. The convergence of the Gram-Charlier expansion involving these spin-orbit moments is analyzed. While a spectrum with infinitely thin components cannot be adequately represented by such an expansion, a suitable convolution procedure ensures the convergence of the Gram-Charlier series provided high-order terms are accounted for. A corrected analytical formula for the third-order moment involving both spin-orbit and electron-electron interactions turns out to be in fair agreement with Cowan's numerical computations.

Spins, charge radii and magnetic moments of neutron-rich Mn isotopes measured with bunched beam Collinear Laser Spectroscopy

CERN Document Server

AUTHOR|(CDS)2085887; Heylen, Hanne

In this work, the odd-even $^{51–63}$Mn isotopes have been analyzed using collinear laser spectroscopy, from which the magnetic dipole moment and the change in change in mean square charge radius can be determined. The magnetic moment is very sensitive to the composition of the total nuclear wave function, while the charge radius gives information about the relative size and degree of deformation of the nucleus. An additional advantage of collinear laser spectroscopy is the possibility of direct measurement of the nuclear spin. The main motivation behind the study of these isotopes is to investigate the change in nuclear structure when approaching neutron number N = 40. This region is of interest due to the apparent doubly magic nature of $^{68}$Ni , which is not seen in the N = 40 isotopes of $^{26}$Fe and $^{24}$Cr. Mn, situated between these elements, offers another perspective due to its uncoupled proton. Based on the observed spectra and extracted moments, spins were assigned to $^{59,61,63}$Mn. The ex...

Distinction of nuclear spin states with the scanning tunneling microscope.

Science.gov (United States)

Natterer, Fabian Donat; Patthey, François; Brune, Harald

2013-10-25

We demonstrate rotational excitation spectroscopy with the scanning tunneling microscope for physisorbed H(2) and its isotopes HD and D(2). The observed excitation energies are very close to the gas phase values and show the expected scaling with the moment of inertia. Since these energies are characteristic for the molecular nuclear spin states we are able to identify the para and ortho species of hydrogen and deuterium, respectively. We thereby demonstrate nuclear spin sensitivity with unprecedented spatial resolution.

Spins, moments and charge radii beyond $^{48}$Ca

CERN Multimedia

Neyens, G; Rajabali, M M; Hammen, M; Blaum, K; Froemmgen, N E; Garcia ruiz, R F; Kreim, K D; Budincevic, I

Laser spectroscopy of $^{49-54}$Ca is proposed as a continuation of the experimental theme initiated with IS484 “Ground-state properties of K-isotopes from laser and $\\beta$-NMR spectroscopy” and expanded in INTC-I-117 “Moments, Spins and Charge Radii Beyond $^{48}$Ca.” It is anticipated that the charge radii of these isotopes can show strong evidence for the existence of a sub-shell closure at N=32 and could provide a first tentative investigation into the existence of a shell effect at N=34. Furthermore the proposed experiments will simultaneously provide model-independent measurements of the spins, magnetic moments and quadrupole moments of $^{51,53}$Ca permitting existing and future excitation spectra to be pinned to firm unambiguous ground states.

Electron spin resonance in YbRh2Si2: local-moment, unlike-spin and quasiparticle descriptions.

Science.gov (United States)

Huber, D L

2012-06-06

Electron spin resonance (ESR) in the Kondo lattice compound YbRh(2)Si(2) has stimulated discussion as to whether the low-field resonance outside the Fermi liquid regime in this material is more appropriately characterized as a local-moment phenomenon or one that requires a Landau quasiparticle interpretation. In earlier work, we outlined a collective mode approach to the ESR that involves only the local 4f moments. In this paper, we extend the collective mode approach to a situation where there are two subsystems of unlike spins: the pseudospins of the ground multiplet of the Yb ions and the spins of the itinerant conduction electrons. We assume a weakly anisotropic exchange interaction between the two subsystems. With suitable approximations our expression for the g-factor also reproduces that found in recent unlike-spin quasiparticle calculations. It is pointed out that the success of the local-moment approach in describing the resonance is due to the fact that the susceptibility of the Yb subsystem dominates that of the conduction electrons with the consequence that the relative shift in the resonance frequency predicted by the unlike-spin models (and absent in the local-moment models) is ≪ 1. The connection with theoretical studies of a two-component model with like spins is also discussed.

Nuclear spin of 185Au and hyperfine structure of 188Au

International Nuclear Information System (INIS)

Ekstroem, C.; Ingelman, S.; Wannberg, G.

1977-03-01

The nuclear spin of 185 Au, I = 5/2, and the hyperfine separation of 188 Au, Δγ = +- 2992(30) MHz, have been measured with the atomic-beam magnetic resonance method. The spin of 185 Au indicates a deformed nuclear shape in the ground state. The small magnetic moment of 188 Au is close in value to those of the heavier I = 1 gold isotopes 190 192 194 Au, being located in a typical transition region. (Auth.)

Nuclear moments, spins and charge radii of copper isotopes from N=28 to N=50 by collinear fast-beam laser spectroscopy

CERN Document Server

2002-01-01

We aim at establishing an unambiguous spin determination of the ground and isomeric states in the neutron rich Cu-isotopes from A=72 up to A=78 and to measure the magnetic and quadrupole moments between the N=28 and N=50 shell closures. This study will provide information on the double-magicity of $^{56}$Ni and $^{78}$Ni, both at the extremes of nuclear stability. It will provide evidence on the suggested inversion of ground state spin around A$\\approx$74, due to the monopole migration of the $\\pi f_{5/2}$ level. The collinear laser spectroscopy technique will be used, which furthermore provides information on the changes in mean square charge radii between both neutron shell closures, probing a possible onset of deformation in this region.

Electric quadruple moments of high-spin isomers in 209Po

International Nuclear Information System (INIS)

Ivanov, E.A.; Nicolescu, G.; Plostinaru, D.

1998-01-01

The electric quadrupole interaction of the 209 Po (17/2) - and (13/2) - isomers in a Bi single-crystal was measured. The results for the quadrupole moments are connected with studies of isomers in Po isotopes. A two level analysis procedure was employed for the combined data of (17/2) - and (13/2) - isomers. The quadrupole moments of the Po isotopes are of special interest for testing nuclear models because of supposed simple nuclear structure with two protons outside a closed magic number shell. While the g-factors are significant for the predominant few-particle structures often present at high spins, the quadrupole moments are sensitive to additional contributions arising from core deformation effects. A systematic study of quadrupole moments of 12 + isomers in Pb isotopes has indeed demonstrated that the valence neutron effective charge increases as more particle pairs are removed from the 208 Pb core. In the present work, quadrupole coupling constants were measured for the isomers by the time-differential perturbed angular distribution (TDPAD) technique, in the presence of quadrupole interactions from the internal electric field gradient (EFG) in Bi crystal. The experiments were performed using a pulsed deuteron-beam of 13 MeV. The (17/2) - isomer state (T 1/2 = 88 ns) and the (13/2) - isomer state (T 1/2 = 24 ns) were populated and aligned by the 209 Bi(d,2n) reaction. The repetition time of the pulse was 10 μs and the width was around 5 ns (FWHM). The rather low bombardment energy was chosen to reduce population of higher spin isomers and to optimize the population of 209 Po((17/2) - ) and 209 Po((13/2) - ). The 209 Po single crystal target was held at a temperature of 470 K in order to reduce possible radiation damage effects. The experiments have been performed with the c axis of the single crystal at 45 angle and 90 angle to the beam direction. We chose to use a calibration based on isomers with well-understood nuclear structure allowing a reliable

Quadrupole moments of low-lying baryons with spin

Indian Academy of Sciences (India)

The chiral constituent quark model ( CQM) with general parametrization (GP) method has been formulated to calculate the quadrupole moments of the spin − 3 2 + decuplet baryons and spin − 3 2 + → 1 2 + transitions. The implications of such a model have been investigated in detail for the effects of symmetry breaking ...

Time reversal violating nuclear polarizability and atomic electric dipole moment

International Nuclear Information System (INIS)

Ginges, J.S.M.; Flambaum, V.V.; Mititelu, G.

2000-01-01

Full text: We propose a nuclear mechanism which can induce an atomic electric dipole moment (EDM). The interaction of external electric E and magnetic H fields with nuclear electric and magnetic dipole moments, d and ,u, gives rise to an energy shift, U= -β ik E i H k , where β ik is the nuclear polarizability. Parity and time invariance violating (P,T-odd) nuclear forces generate a mixed P,T-odd nuclear polarizability, whereψ 0 and ψ n are P,T-odd perturbed ground and excited nuclear states, respectively. In the case of a heavy spherical nucleus with a single unpaired nucleon, the perturbed wavefunctions are U = -β ik E i H k , where ξis a constant proportional to the strength of the nuclear P,T-odd interaction, σ is the nuclear spin operator, and ψ n is an unperturbed wavefunction. There are both scalar and tensor contributions to the nuclear P,T-odd polarizability. An atomic EDM is induced by the interaction of the fields of an unpaired electron in an atom with the P,T-odd perturbed atomic nucleus. An estimate for the value of this EDM has been made. The measurements of atomic EDMs can provide information about P,T-odd nuclear forces and test models of CP-violation

Measurement of nuclear moments and radii by collinear laser spectroscopy

CERN Multimedia

Geithner, W R; Lievens, P; Kotrotsios, G; Silverans, R; Kappertz, S

2002-01-01

%IS304 %title\\\\ \\\\Collinear laser spectroscopy on a fast beam has proven to be a widely applicable and very efficient tool for measurements of changes in mean square nuclear charge radii, nuclear spins, magnetic dipole and electric quadrupole moments. Recent developments of extremely sensitive non-optical detection schemes enabled for some elements the extension of the measurements towards the very short-lived isotopes in the far wings of the ISOLDE production curves. The gain in sensitivity opens up new perspectives, particularly for measurements on lighter nuclei whose ground-state properties can be interpreted by large scale microscopic calculations instead of the more phenomenologic models used for heavier nuclei.\\\\ \\\\ For the sequence of argon isotopes $^{32-40}$Ar and $^{46}$Ar isotope shifts and nuclear moments were measured by optical pumping followed by state selective collisional ionization and detection of the $\\beta$-decay. Similarly, the low-background $\\alpha$-detection was used to extend earlie...

Spins, moments and radii of Cd isotopes

International Nuclear Information System (INIS)

Hammen, Michael

2013-01-01

, the electric quadrupole moments, spins and changes in mean square charge radii are extracted. The obtained data reveal among other features an extremely linear behaviour of the quadrupole moments of the I=11/2 - isomeric states and a parabolic development in differences in mean square nuclear charge radii between ground and isomeric state. The development of charge radii between the shell closures is smooth, exposes a regular odd-even staggering and can be described and interpreted in the model of Zamick and Thalmi.

Spins, moments and radii of Cd isotopes

Energy Technology Data Exchange (ETDEWEB)

Hammen, Michael

2013-10-30

recorded and the magnetic dipole moments, the electric quadrupole moments, spins and changes in mean square charge radii are extracted. The obtained data reveal among other features an extremely linear behaviour of the quadrupole moments of the I=11/2{sup -} isomeric states and a parabolic development in differences in mean square nuclear charge radii between ground and isomeric state. The development of charge radii between the shell closures is smooth, exposes a regular odd-even staggering and can be described and interpreted in the model of Zamick and Thalmi.

Erratum to: Quadrupole moments of low-lying baryons with spin ...

Indian Academy of Sciences (India)

physics pp. 1083. Erratum to: Quadrupole moments of low-lying baryons with spin-. 1. 2. +. , spin-. 3. 2. +. , and spin-. 3. 2. +. → 1. 2. + transitions. NEETIKA SHARMA and HARLEEN DAHIYA. ∗. Department of Physics, Dr. B.R. Ambedkar National Institute of Technology,. Jalandhar 144 011, India. ∗. Corresponding author.

Dynamic nuclear spin polarization

Energy Technology Data Exchange (ETDEWEB)

Stuhrmann, H B [GKSS-Forschungszentrum Geesthacht GmbH (Germany)

1996-11-01

Polarized neutron scattering from dynamic polarized targets has been applied to various hydrogenous materials at different laboratories. In situ structures of macromolecular components have been determined by nuclear spin contrast variation with an unprecedented precision. The experiments of selective nuclear spin depolarisation not only opened a new dimension to structural studies but also revealed phenomena related to propagation of nuclear spin polarization and the interplay of nuclear polarisation with the electronic spin system. The observation of electron spin label dependent nuclear spin polarisation domains by NMR and polarized neutron scattering opens a way to generalize the method of nuclear spin contrast variation and most importantly it avoids precontrasting by specific deuteration. It also likely might tell us more about the mechanism of dynamic nuclear spin polarisation. (author) 4 figs., refs.

Nuclear Anapole Moments

Energy Technology Data Exchange (ETDEWEB)

Michael Ramsey-Musolf; Wick Haxton; Ching-Pang Liu

2002-03-29

Nuclear anapole moments are parity-odd, time-reversal-even E1 moments of the electromagnetic current operator. Although the existence of this moment was recognized theoretically soon after the discovery of parity nonconservation (PNC), its experimental isolation was achieved only recently, when a new level of precision was reached in a measurement of the hyperfine dependence of atomic PNC in 133Cs. An important anapole moment bound in 205Tl also exists. In this paper, we present the details of the first calculation of these anapole moments in the framework commonly used in other studies of hadronic PNC, a meson exchange potential that includes long-range pion exchange and enough degrees of freedom to describe the five independent S-P amplitudes induced by short-range interactions. The resulting contributions of pi-, rho-, and omega-exchange to the single-nucleon anapole moment, to parity admixtures in the nuclear ground state, and to PNC exchange currents are evaluated, using configuration-mixed shell-model wave functions. The experimental anapole moment constraints on the PNC meson-nucleon coupling constants are derived and compared with those from other tests of the hadronic weak interaction. While the bounds obtained from the anapole moment results are consistent with the broad ''reasonable ranges'' defined by theory, they are not in good agreement with the constraints from the other experiments. We explore possible explanations for the discrepancy and comment on the potential importance of new experiments.

Nuclear Anapole Moments

International Nuclear Information System (INIS)

Michael Ramsey-Musolf; Wick Haxton; Ching-Pang Liu

2002-01-01

Nuclear anapole moments are parity-odd, time-reversal-even E1 moments of the electromagnetic current operator. Although the existence of this moment was recognized theoretically soon after the discovery of parity nonconservation (PNC), its experimental isolation was achieved only recently, when a new level of precision was reached in a measurement of the hyperfine dependence of atomic PNC in 133Cs. An important anapole moment bound in 205Tl also exists. In this paper, we present the details of the first calculation of these anapole moments in the framework commonly used in other studies of hadronic PNC, a meson exchange potential that includes long-range pion exchange and enough degrees of freedom to describe the five independent S-P amplitudes induced by short-range interactions. The resulting contributions of pi-, rho-, and omega-exchange to the single-nucleon anapole moment, to parity admixtures in the nuclear ground state, and to PNC exchange currents are evaluated, using configuration-mixed shell-model wave functions. The experimental anapole moment constraints on the PNC meson-nucleon coupling constants are derived and compared with those from other tests of the hadronic weak interaction. While the bounds obtained from the anapole moment results are consistent with the broad ''reasonable ranges'' defined by theory, they are not in good agreement with the constraints from the other experiments. We explore possible explanations for the discrepancy and comment on the potential importance of new experiments

The MONSTER solves nuclear structure problems at low and high spins

International Nuclear Information System (INIS)

Hammaren, E.; Schmid, K.W.; Gruemmer, F.

1984-01-01

A microscopic, particle-number and spin conserving nuclear structure model is discussed. Within a unique theory the model can describe excitation energies, moments, transitions and spectroscopic factors at low and high spins of odd-mass and doubly-even nuclei in all mass regions. With a realistic two-body Hamiltonian extracted via a G-matric description from nucleon-nucleon scattering data. The model is here applied to nuclei in the A=130 region

Hamiltonian action of spinning particle with gravimagnetic moment

International Nuclear Information System (INIS)

Deriglazov, Alexei A; Ramírez, W Guzmán

2016-01-01

We develop Hamiltonian variational problem for spinning particle non-minimally interacting with gravity through the gravimagnetic moment κ. For κ = 0 our model yields Mathisson-Papapetrou-Tulczyjew-Dixon (MPTD) equations, the latter show unsatisfactory behavior of MPTD-particle in ultra-relativistic regime: its longitudinal acceleration increases with velocity. κ = 1 yields a modification of MPTD-equations with the reasonable behavior: in the homogeneous fields, both longitudinal acceleration and (covariant) precession of spin-tensor vanish as v→c. (paper)

Table of Nuclear Magnetic Dipole and Electric Quadrupole Moments

International Nuclear Information System (INIS)

Stone, N.J.

2011-04-01

This Table is a compilation of experimental measurements of static magnetic dipole and electric quadrupole moments of ground states and excited states of atomic nuclei throughout the periodic table. To aid identification of the states, their excitation energy, half-life, spin and parity are given, along with a brief indication of the method and any reference standard used in the particular measurement. The literature search covers the period to late 2010. Many of the entries prior to 1988 follow those in Raghavan P., Atomic and Nuclear Data Tables 42, 189 (1989). (author)

Table of Nuclear Magnetic Dipole and Electric Quadrupole Moments

International Nuclear Information System (INIS)

Stone, N.J.

2014-02-01

This Table is a compilation of experimental measurements of static magnetic dipole and electric quadrupole moments of ground states and excited states of atomic nuclei throughout the periodic table. To aid identification of the states, their excitation energy, half-life, spin and parity are given, along with a brief indication of the method and any reference standard used in the particular measurement. The literature search covers the period to early 2014. Many of the entries prior to 1988 follow those in Raghavan P., Atomic and Nuclear Data Tables 42, 189 (1989). (author)

Moments of inertia in 162Yb at very high spins

International Nuclear Information System (INIS)

Simon, R.S.; Banaschik, M.V.; Colombani, P.; Soroka, D.P.; Stephens, F.S.; Diamond, R.M.

1976-01-01

Two methods have been used to obtain values of the effective moment of inertia of very-high-spin (20h-bar--50h-bar) states populated in heavy-ion compound-nucleus reactions. The 162 Yb nucleus studied has effective moments of inertia smaller than, but approaching, the rigid-body estimate

Nuclear structure studies by means of magnetic moments of excited states

International Nuclear Information System (INIS)

Kaeubler, L.; Prade, H.; Schneider, L.; Brinckmann, H.F.; Stary, F.

1981-09-01

Experimental arrangements installed at the cyclotron U-120 and the tandem accelerator EGP-10 for the in-beam measurement of magnetic moments of excited nuclear states are discribed. The Perturbed-Angular-Distribution-method (PAD) has been used. A new evaluation method has been developed for the unique determination of the Larmor frequency from spin-procession spectra R(t) with less than half of an oscillation period between consecutive particle pulses. Magnetic moments in transitional nuclei or in nuclei near closed shells ( 103 Pd, 105 Ag, 117 Sb, 117 Te, 121 Te, 121 I, 143 Pm and 207 Bi) were measured. The results are discussed with the aim to get information about the nuclear structure of the corresponding isomeric states in connection with complex spectroscopic investigations. Therefore, the experimental values are compared to the results of model calculations (core-polarization, core-particle-coupling, Nilsson, particle-rotation-coupling or shell-model) or to the estimates on the basis of the additivity of effective magnetic moments. Single-particle aspects are discussed in connection with the magnetic moments of hsub(11/2)-, dsub(5/2)- and gsub(7/2)-neutron (ν) and proton (π) states in the nuclei 103 Pd, 117 Te, 121 Te and 143 Pm, respectively. The configurations of (π) 3 and (π)(ν) 2 -three-particle states in 105 Ag, 117 Sb, 121 I and 207 Bi could be determined using the additivity rule. The experimental magnetic moments of states in 143 Pm agree very well with the results of shell-model calculations, which have firstly been carried out also for negative-parity states in this mass region. Considering magnetic moments in 117 Te and 121 Te we could demonstrate the influence of different nuclear deformations on the magnetic moments in transitional nuclei. (author)

Spin temperature concept verified by optical magnetometry of nuclear spins

Science.gov (United States)

Vladimirova, M.; Cronenberger, S.; Scalbert, D.; Ryzhov, I. I.; Zapasskii, V. S.; Kozlov, G. G.; Lemaître, A.; Kavokin, K. V.

2018-01-01

We develop a method of nonperturbative optical control over adiabatic remagnetization of the nuclear spin system and apply it to verify the spin temperature concept in GaAs microcavities. The nuclear spin system is shown to exactly follow the predictions of the spin temperature theory, despite the quadrupole interaction that was earlier reported to disrupt nuclear spin thermalization. These findings open a way for the deep cooling of nuclear spins in semiconductor structures, with the prospect of realizing nuclear spin-ordered states for high-fidelity spin-photon interfaces.

Torque for electron spin induced by electron permanent electric dipole moment

Energy Technology Data Exchange (ETDEWEB)

Senami, Masato, E-mail: senami@me.kyoto-u.ac.jp, E-mail: akitomo@scl.kyoto-u.ac.jp; Fukuda, Masahiro, E-mail: senami@me.kyoto-u.ac.jp, E-mail: akitomo@scl.kyoto-u.ac.jp; Ogiso, Yoji, E-mail: senami@me.kyoto-u.ac.jp, E-mail: akitomo@scl.kyoto-u.ac.jp; Tachibana, Akitomo, E-mail: senami@me.kyoto-u.ac.jp, E-mail: akitomo@scl.kyoto-u.ac.jp [Department of Micro Engineering, Kyoto University, Kyoto 615-8540 (Japan)

2014-10-06

The spin torque of the electron is studied in relation to the electric dipole moment (EDM) of the electron. The spin dynamics is known to be given by the spin torque and the zeta force in quantum field theory. The effect of the EDM on the torque of the spin brings a new term in the equation of motion of the spin. We study this effect for a solution of the Dirac equation with electromagnetic field.

Isotopic and spin-nuclear effects in solid hydrogens (Review Article)

Science.gov (United States)

Freiman, Yuri A.; Crespo, Yanier

2017-12-01

The multiple isotopic family of hydrogens (H2, HD, D2, HT, DT, T2) due to large differences in the de Boer quantum parameter and inertia moments displays a diversity of pronounced quantum isotopic solid-state effects. The homonuclear members of this family (H2, D2, T2) due to the permutation symmetry are subjects of the constraints of quantum mechanics which link the possible rotational states of these molecules to their total nuclear spin giving rise to the existence of two spin-nuclear modifications, ortho- and parahydrogens, possessing substantially different properties. Consequently, hydrogen solids present an unique opportunity for studying both isotope and spin-nuclear effects. The rotational spectra of heteronuclear hydrogens (HD, HT, DT) are free from limitations imposed by the permutation symmetry. As a result, the ground state of these species in solid state is virtually degenerate. The most dramatic consequence of this fact is an effect similar to the Pomeranchuk effect in 3He which in the case of the solid heteronuclear hydrogens manifests itself as the reentrant broken symmetry phase transitions. In this review article we discuss thermodynamic and kinetic effects pertaining to different isotopic and spin-nuclear species, as well as problems that still remain to be solved.

Nuclear spins in nanostructures

International Nuclear Information System (INIS)

Coish, W.A.; Baugh, J.

2009-01-01

We review recent theoretical and experimental advances toward understanding the effects of nuclear spins in confined nanostructures. These systems, which include quantum dots, defect centers, and molecular magnets, are particularly interesting for their importance in quantum information processing devices, which aim to coherently manipulate single electron spins with high precision. On one hand, interactions between confined electron spins and a nuclear-spin environment provide a decoherence source for the electron, and on the other, a strong effective magnetic field that can be used to execute local coherent rotations. A great deal of effort has been directed toward understanding the details of the relevant decoherence processes and to find new methods to manipulate the coupled electron-nuclear system. A sequence of spectacular new results have provided understanding of spin-bath decoherence, nuclear spin diffusion, and preparation of the nuclear state through dynamic polarization and more general manipulation of the nuclear-spin density matrix through ''state narrowing.'' These results demonstrate the richness of this physical system and promise many new mysteries for the future. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

Quadrupole moments measured by nuclear orientation

International Nuclear Information System (INIS)

Bouchta, H.

1985-01-01

Quadrupole interactions between the nuclei and solids have been studied with the low temperature nuclear orientation technique. The first series of measurements have been effected on the orientation of 195H g m and 197 Hg m , long lived daughter states in the 195 Au and 197 Au decay. The lifetimes of these states are of the same order as the spin-lattice relaxation time. The reorientation of the intermediate states has been taken into account extending the dipole relaxation mechanism to non-equidistant relaxing substates. The experimental nuclear quadrupole moments, thus deduced are slightly different from theoretical estimations. A new high precision method accessible to levels with 100 ns to 1 m lifetimes, the level mixing resonance on oriented nuclei (LMR/ON) has been elaborated in collaboration with LEUVEN university (Belgium). In this technique the nucleus is subject to a non colinear electric plus magnetic combined interaction. The quadrupole interaction of Ag[7/2, = 40 s] isomer with the electric field gradient in zinc has been established to better than 1% observing its level mixing resonances; and also the ratio of electric field gradients of silver in zinc to cadmium. The electric quadrupole moments of 106 Ag m , 107 Ag m and 109 Ag m have been established combining the level mixing resonances with classical low temperature quadrupole alignment measurements. The experimental values are in good agreement with theoretical calculations based on a semi-microscopical model using Yukawa potential [fr

Nuclear spin noise in the central spin model

Science.gov (United States)

Fröhling, Nina; Anders, Frithjof B.; Glazov, Mikhail

2018-05-01

We study theoretically the fluctuations of the nuclear spins in quantum dots employing the central spin model which accounts for the hyperfine interaction of the nuclei with the electron spin. These fluctuations are calculated both with an analytical approach using homogeneous hyperfine couplings (box model) and with a numerical simulation using a distribution of hyperfine coupling constants. The approaches are in good agreement. The box model serves as a benchmark with low computational cost that explains the basic features of the nuclear spin noise well. We also demonstrate that the nuclear spin noise spectra comprise a two-peak structure centered at the nuclear Zeeman frequency in high magnetic fields with the shape of the spectrum controlled by the distribution of the hyperfine constants. This allows for direct access to this distribution function through nuclear spin noise spectroscopy.

Nuclear spin: Fifty years of ups and downs

Energy Technology Data Exchange (ETDEWEB)

Pines, A. [Lawrence Berkeley National Lab., CA (United States)

1996-12-31

Rumors of its demise notwithstanding, nuclear magnetic resonance (NMR) continues to flourish fifty years after our birth. The lecture will be a reminiscence about moments of excitation, coherence and relaxation in the history of NMR which produced, among other developments, spin echoes and time reversal, Fourier transform and multidimensional spectroscopy, magnetic resonance imaging, and high resolution solid state NMR. Applications of modern NMR spectroscopy cut across the boundaries of physics, chemistry, materials, biology and medicine.

Studies of nuclear second moments for pre-equilibrium nuclear reaction theories

International Nuclear Information System (INIS)

Sato, K.; Yoshida, S.

1987-01-01

The nuclear second moments, important inputs to pre-equilibrium reaction theories, are evaluated by assuming a simple model. The positive definite nature of the second moments is examined, and the nuclear level densities are calculated using positive definite second moments. (orig.)

Enhanced nuclear magnetism: some novel features and prospective experiments

International Nuclear Information System (INIS)

Abragam, A.; Bleaney, B.

1983-01-01

It is shown that methods used for studying nuclear magnetism and nuclear magnetic ordering can be extended to 'enhanced nuclear magnetism'. These methods include the use of r.f. fields for adiabatic demagnetization in the rotating frame (a.d.r.f) and beams of neutrons whose spins interact with the nuclear spins. The 'enhancement' of the nuclear moment arises from the electronic magnetization M 1 induced through the hyperfine interaction. It is shown that the spatial distribution of M 1 is the same as that of The Van Vleck magnetization induced by an external field, provided that J is a good quantum number. The spatial distributions are not in general the same in Russell-Saunders coupling, eg. in the 3d group. The Bloch equations are extended to include anisotropic nuclear moments. The 'truncated' spin Hamiltonian is derived for spin-spin interaction between enhanced moments. A general cancellation theorem for second-order processes in spin-lattice relaxation is derived. The interactions of neutrons with the true nuclear moment, the Van Vleck moment, the 'pseudonuclear' moment and the 'pseudomagnetic' nuclear moment are discussed. Ordered states of enhanced nuclear moment systems are considered, together with the conditions under which they might be produced by a.d.r.f. following dynamic nuclear polarization. (U.K.)

Control of electron spin decoherence in nuclear spin baths

Science.gov (United States)

Liu, Ren-Bao

2011-03-01

Nuclear spin baths are a main mechanism of decoherence of spin qubits in solid-state systems, such as quantum dots and nitrogen-vacancy (NV) centers of diamond. The decoherence results from entanglement between the electron and nuclear spins, established by quantum evolution of the bath conditioned on the electron spin state. When the electron spin is flipped, the conditional bath evolution is manipulated. Such manipulation of bath through control of the electron spin not only leads to preservation of the center spin coherence but also demonstrates quantum nature of the bath. In an NV center system, the electron spin effectively interacts with hundreds of 13 C nuclear spins. Under repeated flip control (dynamical decoupling), the electron spin coherence can be preserved for a long time (> 1 ms) . Thereforesomecharacteristicoscillations , duetocouplingtoabonded 13 C nuclear spin pair (a dimer), are imprinted on the electron spin coherence profile, which are very sensitive to the position and orientation of the dimer. With such finger-print oscillations, a dimer can be uniquely identified. Thus, we propose magnetometry with single-nucleus sensitivity and atomic resolution, using NV center spin coherence to identify single molecules. Through the center spin coherence, we could also explore the many-body physics in an interacting spin bath. The information of elementary excitations and many-body correlations can be extracted from the center spin coherence under many-pulse dynamical decoupling control. Another application of the preserved spin coherence is identifying quantumness of a spin bath through the back-action of the electron spin to the bath. We show that the multiple transition of an NV center in a nuclear spin bath can have longer coherence time than the single transition does, when the classical noises due to inhomogeneous broadening is removed by spin echo. This counter-intuitive result unambiguously demonstrates the quantumness of the nuclear spin bath

Evolution of nuclear shapes at high spins

International Nuclear Information System (INIS)

Johnson, N.R.

1985-01-01

The dynamic electric quadrupole (E2) moments are a direct reflection of the collective aspects of the nuclear wave functions. For this, Doppler-shift lifetime measurements have been done utilizing primarily the recoil-distance technique. The nuclei with neutron number N approx. 90 possess many interesting properties. These nuclei have very shallow minima in their potential energy surfaces, and thus, are very susceptible to deformation driving influences. It is the evolution of nuclear shapes as a function of spin or rotational frequency for these nuclei that has commanded much interest in the lifetime measurements discussed here. There is growing evidence that many deformed nuclei which have prolate shapes in their ground states conform to triaxial or oblate shapes at higher spins. Since the E2 matrix elements along the yrast line are sensitive indicators of deformation changes, measurements of lifetimes of these states to provide the matrix elements has become the major avenue for tracing the evolving shape of a nucleus at high spin. Of the several nuclei we have studied with N approx. 90, those to be discussed here are /sup 160,161/Yb and 158 Er. In addition, the preliminary, but interesting and surprising results from our recent investigation of the N = 98 nucleus, 172 W are briefly discussed. 14 refs., 5 figs

Electron spin and nuclear spin manipulation in semiconductor nanosystems

International Nuclear Information System (INIS)

Hirayama, Yoshiro; Yusa, Go; Sasaki, Satoshi

2006-01-01

Manipulations of electron spin and nuclear spin have been studied in AlGaAs/GaAs semiconductor nanosystems. Non-local manipulation of electron spins has been realized by using the correlation effect between localized and mobile electron spins in a quantum dot- quantum wire coupled system. Interaction between electron and nuclear spins was exploited to achieve a coherent control of nuclear spins in a semiconductor point contact device. Using this device, we have demonstrated a fully coherent manipulation of any two states among the four spin levels of Ga and As nuclei. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Electromagnetic properties for arbitrary spin particles: Natural electromagnetic moments from light-cone arguments

International Nuclear Information System (INIS)

Lorce, Cedric

2009-01-01

We revisit the old-standing problem of the electromagnetic interaction for particles of arbitrary spin. Based on the assumption that light-cone helicity at tree level and Q 2 =0 should be conserved nontrivially by the electromagnetic interaction, we are able to derive all the natural electromagnetic moments for a pointlike particle of any spin. We provide here a transparent decomposition of the electromagnetic current in terms of covariant vertex functions. We also define in a general way the electromagnetic multipole form factors, and show their relation with the electromagnetic moments and covariant vertex functions. The light-cone helicity conservation argument determines uniquely the values of all electromagnetic moments, which we refer to as the 'natural' ones. These specific values are in accordance with the standard model, and the prediction of universal g=2 gyromagnetic factor is naturally recovered. We provide a very simple and compact formula for these natural moments. As an application of our results, we generalize the discussion of quark transverse charge densities to particles with arbitrary spin, giving more physical support to the light-cone helicity conservation argument.

An online database of nuclear electromagnetic moments

International Nuclear Information System (INIS)

Mertzimekis, T.J.; Stamou, K.; Psaltis, A.

2016-01-01

Measurements of nuclear magnetic dipole and electric quadrupole moments are considered quite important for the understanding of nuclear structure both near and far from the valley of stability. The recent advent of radioactive beams has resulted in a plethora of new, continuously flowing, experimental data on nuclear structure – including nuclear moments – which hinders the information management. A new, dedicated, public and user friendly online database ( (http://magneticmoments.info)) has been created comprising experimental data of nuclear electromagnetic moments. The present database supersedes existing printed compilations, including also non-evaluated series of data and relevant meta-data, while putting strong emphasis on bimonthly updates. The scope, features and extensions of the database are reported.

Nuclear structure at high and very high spin theoretical description

International Nuclear Information System (INIS)

Szymanski, Z.

1983-11-01

When the existence of nuclear shell structure is ignored and nuclear motion is assumed to be classical we may expect that the nuclear rotation resembles that of a liquid drop. Energy of the nucleus can be thus considered as a sum of three terms: surface energy, Coulomb energy and rotational energy. Nuclear moment of inertia is assumed to be that of a rigid-body. The results of a calculation of the energy surfaces in rotating nuclei by Cohen, Plasil and Swiatecki are discussed. Cranking procedure is analysed as a tool to investigate nucleonic orbits in a rotating nuclear potential. Some predictions concerning the possible onset of a superdeformed phase are given. The structure of nuclear rotation is examined in the presence of the short-range pairing forces that generate the superfluid correlations in the nucleus. Examples of the Bengtsson-Frauendorf plots (quasiparticle energies versus angular velocity of rotation) are given and discussed. The backbending phenomenon is analysed in terms of band crossing. The dependence of the crossing frequency on the pairing-force strength is discussed. Possibilities of the role of new components in the two-body force (quadrupole-pairing) are considered. Possibilities of the phase transition from superfluid to normal states in the nucleus are analysed. The role of the second (dynamic) moment of inertia I(2) in this analysis is discussed. In spherical weekly deformed nuclei (mostly oblate) angular momentum is aligned parallel to the nuclear symmetry axis. Rotation is of non collective origin in this case. Examples of the analysis of nuclear spectra in this case (exhibiting also the isomeric states called yrast (traps)) are given. Possible forms of the collective excitations superimposed on top of the high-spin states are discussed. In particular, the giant resonance excitations formed on top of the high-spin states are considered and their properties discussed

A new online database of nuclear electromagnetic moments

Science.gov (United States)

Mertzimekis, Theo J.

2017-09-01

Nuclear electromagnetic (EM) moments, i.e., the magnetic dipole and the electric quadrupole moments, provide important information of nuclear structure. As in other types of experimental data available to the community, measurements of nuclear EM moments have been organized systematically in compilations since the dawn of nuclear science. However, the wealth of recent moments measurements with radioactive beams, as well as earlier existing measurements, lack an online, easy-to-access, systematically organized presence to disseminate information to researchers. In addition, available printed compilations suffer a rather long life cycle, being left behind experimental measurements published in journals or elsewhere. A new, online database (http://magneticmoments.info) focusing on nuclear EM moments has been recently developed to disseminate experimental data to the community. The database includes non-evaluated experimental data of nuclear EM moments, giving strong emphasis on frequent updates (life cycle is 3 months) and direct connection to the sources via DOI and NSR hyperlinks. It has been recently integrated in IAEA LiveChart [1], but can also be found as a standalone webapp [2]. A detailed review of the database features, as well as plans for further development and expansion in the near future is discussed.

Impurity-induced moments in underdoped cuprates

International Nuclear Information System (INIS)

Khaliullin, G.; Kilian, R.; Krivenko, S.; Fulde, P.

1997-01-01

We examine the effect of a nonmagnetic impurity in a two-dimensional spin liquid in the spin-gap phase, employing a drone-fermion representation of spin-1/2 operators. The properties of the local moment induced in the vicinity of the impurity are investigated and an expression for the nuclear-magnetic-resonance Knight shift is derived, which we compare with experimental results. Introducing a second impurity into the spin liquid an antiferromagnetic interaction between the moments is found when the two impurities are located on different sublattices. The presence of many impurities leads to a screening of this interaction as is shown by means of a coherent-potential approximation. Further, the Kondo screening of an impurity-induced local spin by charge carriers is discussed. copyright 1997 The American Physical Society

Algorithm for the generation of nuclear spin species and nuclear spin statistical weights

International Nuclear Information System (INIS)

Balasubramanian, K.

1982-01-01

A set of algorithms for the computer generation of nuclear spin species and nuclear spin statistical weights potentially useful in molecular spectroscopy is developed. These algorithms generate the nuclear spin species from group structures known as generalized character cycle indices (GCCIs). Thus the required input for these algorithms is just the set of all GCCIs for the symmetry group of the molecule which can be computed easily from the character table. The algorithms are executed and illustrated with examples

Theory of nuclear magnetic moments - LT-35

Energy Technology Data Exchange (ETDEWEB)

Kerman, A. K.

1952-09-15

The purpose of these notes is to give an account of some attempts at interpreting the observed values of nuclear magnetic moments. There is no attempt at a complete summary of the field as that would take much more space than is used here. In many cases the arguments are only outlined and references are given for those interested in further details. A discussion of the theory of nuclear magnetic moments necessitates many excursions into the details of the nuclear models because the magnetic moments have a direct bearing on the validity of these models. However the main emphasis here is on those features which tend to explain the magnetic moments and other evidence is not discussed unless it has a direct bearing on the problem. In the first part of the discussion the Shell Model of the nucleus is used, as this model seems to correlate a large body of data relating to the heavier nuclei. Included here are the modifications proposed to explain the fact that the experimental magnetic moments do not fit quantitatively with the exact predictions of the Shell Model. The next sections deal with some of the more drastic modifications introduced to explain the large nuclear quadrupole moments and the effect of these modifications on the magnetic moments. Finally we turn to more detailed investigations of the light nuclei, in particular the - Conjugate nuclei. (author)

Quantum dynamics of nuclear spins and spin relaxation in organic semiconductors

Science.gov (United States)

Mkhitaryan, V. V.; Dobrovitski, V. V.

2017-06-01

We investigate the role of the nuclear-spin quantum dynamics in hyperfine-induced spin relaxation of hopping carriers in organic semiconductors. The fast-hopping regime, when the carrier spin does not rotate much between subsequent hops, is typical for organic semiconductors possessing long spin coherence times. We consider this regime and focus on a carrier random-walk diffusion in one dimension, where the effect of the nuclear-spin dynamics is expected to be the strongest. Exact numerical simulations of spin systems with up to 25 nuclear spins are performed using the Suzuki-Trotter decomposition of the evolution operator. Larger nuclear-spin systems are modeled utilizing the spin-coherent state P -representation approach developed earlier. We find that the nuclear-spin dynamics strongly influences the carrier spin relaxation at long times. If the random walk is restricted to a small area, it leads to the quenching of carrier spin polarization at a nonzero value at long times. If the random walk is unrestricted, the carrier spin polarization acquires a long-time tail, decaying as 1 /√{t } . Based on the numerical results, we devise a simple formula describing the effect quantitatively.

The Nuclear Spin Nanomagnet

OpenAIRE

Korenev, V. L.

2007-01-01

Linearly polarized light tuned slightly below the optical transition of the negatively charged exciton (trion) in a single quantum dot causes the spontaneous nuclear spin polarization (self-polarization) at a level close to 100%. The effective magnetic field of spin-polarized nuclei brings the optical transition energy into resonance with photon energy. The resonantly enhanced Overhauser effect sustains the stability of the nuclear self-polarization even in the absence of spin polarization of...

Nuclear spin-lattice relaxation in nitroxide spin-label EPR.

Science.gov (United States)

Marsh, Derek

2016-11-01

Nuclear relaxation is a sensitive monitor of rotational dynamics in spin-label EPR. It also contributes competing saturation transfer pathways in T 1 -exchange spectroscopy, and the determination of paramagnetic relaxation enhancement in site-directed spin labelling. A survey shows that the definition of nitrogen nuclear relaxation rate W n commonly used in the CW-EPR literature for 14 N-nitroxyl spin labels is inconsistent with that currently adopted in time-resolved EPR measurements of saturation recovery. Redefinition of the normalised 14 N spin-lattice relaxation rate, b=W n /(2W e ), preserves the expressions used for CW-EPR, whilst rendering them consistent with expressions for saturation recovery rates in pulsed EPR. Furthermore, values routinely quoted for nuclear relaxation times that are deduced from EPR spectral diffusion rates in 14 N-nitroxyl spin labels do not accord with conventional analysis of spin-lattice relaxation in this three-level system. Expressions for CW-saturation EPR with the revised definitions are summarised. Data on nitrogen nuclear spin-lattice relaxation times are compiled according to the three-level scheme for 14 N-relaxation: T 1 n =1/W n . Results are compared and contrasted with those for the two-level 15 N-nitroxide system. Copyright © 2016 Elsevier Inc. All rights reserved.

Nuclear anapole moment and tests of the standard model

International Nuclear Information System (INIS)

Flambaum, V. V.

1999-01-01

There are two sources of parity nonconservation (PNC) in atoms: the electron-nucleus weak interaction and the magnetic interaction of electrons with the nuclear anapole moment. A nuclear anapole moment has recently been observed. This is the first discovery of an electromagnetic moment violating fundamental symmetries--the anapole moment violates parity and charge-conjugation invariance. We describe the anapole moment and how it can be produced. The anapole moment creates a circular magnetic field inside the nucleus. The interesting point is that measurements of the anapole allow one to study parity violation inside the nucleus through atomic experiments. We use the experimental result for the nuclear anapole moment of 133 Cs to find the strengths of the parity violating proton-nucleus and meson-nucleon forces. Measurements of the weak charge characterizing the strength of the electron-nucleon weak interaction provide tests of the Standard Model and a way of searching for new physics beyond the Standard Model. Atomic experiments give limits on the extra Z-boson, leptoquarks, composite fermions, and radiative corrections produced by particles that are predicted by new theories. The weak charge and nuclear anapole moment can be measured in the same experiment. The weak charge gives the mean value of the PNC effect while the anapole gives the difference of the PNC effects for the different hyperfine components of an electromagnetic transition. The interaction between atomic electrons and the nuclear anapole moment may be called the ''PNC hyperfine interaction.''

Suggested search for 207Pb nuclear Schiff moment in PbTiO3 ferroelectric

International Nuclear Information System (INIS)

Mukhamedjanov, T.N.; Sushkov, O.P.

2005-01-01

We suggest two types of experiments, NMR and macroscopic magnetometry, with solid PbTiO 3 to search for the nuclear Schiff moment of 207 Pb. Both kinds of experiments promise substantial improvement over the presently achieved sensitivities. Statistical considerations show that the improvement of the current sensitivity can be up to ten orders of magnitude for the magnetometry experiment and up to seven orders of magnitude for the NMR experiment. Such significant enhancement is due to the strong internal electric field of the ferroelectric, as well as due to the possibility to cool the nuclear-spin subsystem in the compound down to nanokelvin temperatures

Local spin torque induced by electron electric dipole moment in the YbF molecule

Energy Technology Data Exchange (ETDEWEB)

Fukuda, Masahiro; Senami, Masato; Ogiso, Yoji; Tachibana, Akitomo [Department of Micro Engineering, Kyoto University, Kyoto 615-8540 (Japan)

2014-10-06

In this study, we show the modification of the equation of motion of the electronic spin, which is derived by the quantum electron spin vorticity principle, by the effect of the electron electric dipole moment (EDM). To investigate the new contribution to spin torque by EDM, using first principle calculations, we visualize distributions of the local spin angular momentum density and local spin torque density of the YbF molecule on which the static electric field and magnetic field are applied at t = 0.

Lorentz-violating contributions to the nuclear Schiff moment and nuclear EDM

Science.gov (United States)

Araujo, Jonas B.; Casana, Rodolfo; Ferreira, Manoel M.

2018-03-01

In the context of an atom endowed with nuclear electric dipole moments (EDM), we consider the effects on the Schiff moment of C P T -even Lorentz-violating (LV) terms that modify the Coulomb potential. First, we study the modifications on the Schiff moment when the nucleus interacts with the electronic cloud by means of a Coulomb potential altered only by the P -even LV components. Next, by supposing the existence of an additional intrinsic LV EDM generated by other LV sources, we assess the corrections to the Schiff moment when the interaction nucleus-electrons runs mediated by a Coulomb potential modified by both the P -odd and P -even LV components. We then use known estimates and EDM measurements to discuss upper bounds on the new Schiff moment components and the possibility of a nuclear EDM component ascribed to LV effects.

Nuclear spin-lattice relaxation in nitroxide spin-label EPR

DEFF Research Database (Denmark)

Marsh, Derek

2016-01-01

that the definition of nitrogen nuclear relaxation rate Wn commonly used in the CW-EPR literature for 14N-nitroxyl spin labels is inconsistent with that currently adopted in time-resolved EPR measurements of saturation recovery. Redefinition of the normalised 14N spin-lattice relaxation rate, b = Wn/(2We), preserves...... of spin-lattice relaxation in this three-level system. Expressions for CW-saturation EPR with the revised definitions are summarised. Data on nitrogen nuclear spin-lattice relaxation times are compiled according to the three-level scheme for 14N-relaxation: T1 n = 1/Wn. Results are compared and contrasted...

Nuclear magnetic and electric dipole moments of neon-19

International Nuclear Information System (INIS)

MacArthur, D.W.

1983-01-01

This thesis presents a detailed discussion of a series of experiments designed to measure the magnetic and electric dipole moments of the β-emitting nucleus 19 Ne. The 19 Ne is generated in the reaction 19 F(p,n) 19 Ne and is polarized by a ''stern-Gerlach'' magnet in a rare gas atomic beams machine. The atoms are stored in a cell for many seconds without depolarizing. The parity violating asymmetry in the β angular distribution is used to monitor the nuclear polarization. The polarized atoms are stored in a cell in a uniform magnetic field. The β-asymmetry is monitored by a pair of β-detectors located on either side of the cell. Transitions between the M/sub J/ = +1/2 and M/sub J/ = -1/2 spin states are induced by an rf field generated by a small Helmholtz coil pair surrounding the cell. Nuclear magnetic resonance lines are observed and the magnetic moment of 19 Ne measured to be μ( 19 Ne) = -1.88542(8)μ/sub N/. A new magnet, cell and detectors were designed to give narrow resonance lines. The equipment is described in detail and several resonance line shapes are discussed. The narrowest resonance line achieved with this system was 0.043 Hz FWHM. This width is primarily due to the 19 Ne lifetime. Pulsed NMR lineshapes were also observed. The narrow NMR lines observed in the previous experiment were then used as a probe to look for an electric dipole moment (EDM) in 19 Ne. Any shift in the resonance frequency correlated with changes in an externally applied electric field would be evidence for an EDM. The EDM of the 19 Ne atom was measured to (7.2 +/- 6.2 X 10 -22 e-cm. This experiment and possible improvements are discussed in detail

Temperature dependence of spin and orbital magnetic moments of Sm 4f electrons in (Sm, Gd)Al2

International Nuclear Information System (INIS)

Qiao, S.; Kimura, A.; Adachi, H.; Iori, K.; Miyamoto, K.; Xie, T.; Namatame, H.; Taniguchi, M.; Tanaka, A.; Muro, T.; Imada, S.; Suga, S.

2005-01-01

X-ray magnetic circular dichroism studies were carried out on (Sm, Gd)Al 2 , a ferromagnet without net magnetization at a certain compensation temperature. For Sm 4f electrons, the following understandings were obtained: the magnitude of expectation value of orbital magnetic moment (m L Sm ) is always larger than that of spin one (m S Sm ), so the cancellation of total spin and orbital magnetic moments cannot be achieved only by Sm 4f electrons and the contributions from Gd ions and conduction electrons are important; when the temperature decreases, the magnitude of both m L Sm and m S Sm increases and the gross magnetic moment due to the Sm 4f electrons monotonically deviates from zero. These results tell us that the temperature dependence of magnetic moments related with the electrons other than Sm 4f ones may play important roles in the subtle adjustment of the total spin and orbital magnetic moments to the zero magnetization at the compensation temperature

Gross shell structure of moments of inertia

International Nuclear Information System (INIS)

Deleplanque, M.A.; Frauendorf, S.; Pashkevich, V.V.; Chu, S.Y.; Unzhakova, A.

2002-01-01

Average yrast moments of inertia at high spins, where the pairing correlations are expected to be largely absent, were found to deviate from the rigid-body values. This indicates that shell effects contribute to the moment of inertia. We discuss the gross dependence of moments of inertia and shell energies on the neutron number in terms of the semiclassical periodic orbit theory. We show that the ground-state shell energies, nuclear deformations and deviations from rigid-body moments of inertia are all due to the same periodic orbits

About the parametrizations utilized to perform magnetic moments measurements using the transient field technique

Energy Technology Data Exchange (ETDEWEB)

Gómez, A. M., E-mail: amgomezl-1@uqvirtual.edu.co [Programa de Física, Universidad del Quindo (Colombia); Torres, D. A., E-mail: datorresg@unal.edu.co [Physics Department, Universidad Nacional de Colombia, Bogotá (Colombia)

2016-07-07

The experimental study of nuclear magnetic moments, using the Transient Field technique, makes use of spin-orbit hyperfine interactions to generate strong magnetic fields, above the kilo-Tesla regime, capable to create a precession of the nuclear spin. A theoretical description of such magnetic fields is still under theoretical research, and the use of parametrizations is still a common way to address the lack of theoretical information. In this contribution, a review of the main parametrizations utilized in the measurements of Nuclear Magnetic Moments will be presented, the challenges to create a theoretical description from first principles will be discussed.

Magnetic dipole moments of deformed odd-A nuclei

Energy Technology Data Exchange (ETDEWEB)

Garg, V P; Sharma, S D; Mahesh, P S [Punjabi Univ., Patiala (India). Dept. of Physics

1976-12-01

Using an extended version of A S Davydov and G F Filippov's model (1958), B E Chi and J P Davidson have calculated magnetic moments of odd-A nuclei in 2s-ld shell, diagonalizing the state matrices for a set of parameters giving the best fit for nuclear spectra (1966). To study the failure of this model in case of nuclear moments, instead of diagonalizing an attempt has been made to simplify the expression for magnetic dipole moment for single nucleonic states without configuration mixing. The model takes care of the proper sign of spin projections. On replacing the total angular momentum j of odd particle (proton or neutron) by its projection ..cap omega.., the expression reduces to that of Mottelson and Nilsson for spin-up nuclei. The Coriolis coupling calculations also have been performed for those odd-A nuclei with K = 1/2. The results are found in better agreement with experimental report in comparison with those of other models.

Spin alignment and collective moment of inertia of the basic rotational band in the cranking model

International Nuclear Information System (INIS)

Tanaka, Yoshihide

1982-01-01

By making an attempt to separate the intrinsic particle and collective rotational motions in the cranking model, the spin alignment and the collective moment of inertia characterizing the basic rotational bands are defined, and are investigated by using a simple i sub(13/2) shell model. The result of the calculation indicates that the collective moment of inertia decreases under the presence of the quasiparticles which are responsible for the increase of the spin alignment of the band. (author)

Calculation of the atomic electric dipole moment of Pb2+ induced by nuclear Schiff moment

Science.gov (United States)

Ramachandran, S. M.; Latha, K. V. P.; Meenakshisundaram, N.

2017-07-01

We report the atomic electric dipole moment induced by the P, T violating interactions in the nuclear/sub-nuclear level, for 207Pb2+ and 207Pb, owing to the recent interest in the ferroelectric crystal PbTiO3 as one of the candidates for investigating macroscopic P, T-odd effects. In this paper, we calculate the atomic electric dipole moments of 207Pb and Pb2+, parametrized in terms of the P, T-odd coupling parameter, the nuclear Schiff moment (NSM), S, in the frame-work of the coupled-perturbed Hartree-Fock theory. We estimate the Schiff moment of Pb2+ using the experimental result of a system, which is electronically similar to the Pb2+ ion. We present the dominant contributions of the electric dipole moment (EDM) matrix elements and the important correlation effects contributing to the atomic EDM of Pb2+. Our results provide the first ever calculated EDM of the Pb2+ ion, and an estimate of its NSM from which the P, T-odd energy shift in a PbTiO3 crystal can be evaluated.

Optically induced dynamic nuclear spin polarisation in diamond

International Nuclear Information System (INIS)

Scheuer, Jochen; Naydenov, Boris; Jelezko, Fedor; Schwartz, Ilai; Chen, Qiong; Plenio, Martin B; Schulze-Sünninghausen, David; Luy, Burkhard; Carl, Patrick; Höfer, Peter; Retzker, Alexander; Sumiya, Hitoshi; Isoya, Junichi

2016-01-01

The sensitivity of magnetic resonance imaging (MRI) depends strongly on nuclear spin polarisation and, motivated by this observation, dynamical nuclear spin polarisation has recently been applied to enhance MRI protocols (Kurhanewicz et al 2011 Neoplasia 13 81). Nuclear spins associated with the 13 C carbon isotope (nuclear spin I = 1/2) in diamond possess uniquely long spin lattice relaxation times (Reynhardt and High 2011 Prog. Nucl. Magn. Reson. Spectrosc. 38 37). If they are present in diamond nanocrystals, especially when strongly polarised, they form a promising contrast agent for MRI. Current schemes for achieving nuclear polarisation, however, require cryogenic temperatures. Here we demonstrate an efficient scheme that realises optically induced 13 C nuclear spin hyperpolarisation in diamond at room temperature and low ambient magnetic field. Optical pumping of a nitrogen-vacancy centre creates a continuously renewable electron spin polarisation which can be transferred to surrounding 13 C nuclear spins. Importantly for future applications we also realise polarisation protocols that are robust against an unknown misalignment between magnetic field and crystal axis. (paper)

Nuclear spin-lattice relaxation in carbon nanostructures

Energy Technology Data Exchange (ETDEWEB)

Panich, A.M., E-mail: pan@bgu.ac.i [Department of Physics, Ben-Gurion University of the Negev, P.O. Box 653, Beer Sheva 84105 (Israel); Sergeev, N.A. [Institute of Physics, University of Szczecin, 70-451 Szczecin (Poland)

2010-04-15

Interpretation of nuclear spin-lattice relaxation data in the carbon nanostructures is usually based on the analysis of fluctuations of dipole-dipole interactions of nuclear spins and anisotropic electron-nuclear interactions responsible for chemical shielding, which are caused by molecular dynamics. However, many nanocarbon systems such as fullerene and nanotube derivatives, nanodiamonds and carbon onions reveal noticeable amount of paramagnetic defects with unpaired electrons originating from dangling bonds. The interaction between nuclear and electron spins strongly influences the nuclear spin-lattice relaxation, but usually is not taken into account, thus the relaxation data are not correctly interpreted. Here we report on the temperature dependent NMR spectra and spin-lattice relaxation measurements of intercalated fullerenes C{sub 60}(MF{sub 6}){sub 2} (M=As and Sb), where nuclear relaxation is caused by both molecular rotation and interaction between nuclei and unpaired electron spins. We present a detailed theoretical analysis of the spin-lattice relaxation data taking into account both these contributions. Good agreement between the experimental data and calculations is obtained. The developed approach would be useful in interpreting the NMR relaxation data in different nanostructures and their intercalation compounds.

Nuclear spin off

International Nuclear Information System (INIS)

1984-01-01

The focus for nuclear energy research in the UK has been mainly the generation of electricity. However, nuclear technology is also applied in many areas other than energy production. Nuclear Spin Off shows how technology has been transferred to industry, agriculture, medicine and other areas, creating considerable material benefit. Nuclear research has produced revolutionary new materials and measuring and detection techniques. This film shows a wide range of uses. (author)

Nuclear spin polarized H and D by means of spin-exchange optical pumping

Science.gov (United States)

Stenger, Jörn; Grosshauser, Carsten; Kilian, Wolfgang; Nagengast, Wolfgang; Ranzenberger, Bernd; Rith, Klaus; Schmidt, Frank

1998-01-01

Optically pumped spin-exchange sources for polarized hydrogen and deuterium atoms have been demonstrated to yield high atomic flow and high electron spin polarization. For maximum nuclear polarization the source has to be operated in spin temperature equilibrium, which has already been demonstrated for hydrogen. In spin temperature equilibrium the nuclear spin polarization PI equals the electron spin polarization PS for hydrogen and is even larger than PS for deuterium. We discuss the general properties of spin temperature equilibrium for a sample of deuterium atoms. One result are the equations PI=4PS/(3+PS2) and Pzz=PSṡPI, where Pzz is the nuclear tensor polarization. Furthermore we demonstrate that the deuterium atoms from our source are in spin temperature equilibrium within the experimental accuracy.

Fen (n=1–6) clusters chemisorbed on vacancy defects in graphene: Stability, spin-dipole moment, and magnetic anisotropy

KAUST Repository

Haldar, Soumyajyoti

2014-05-09

In this work, we have studied the chemical and magnetic interactions of Fen (n=1–6) clusters with vacancy defects (monovacancy to correlated vacancies with six missing C atoms) in a graphene sheet by ab initio density functional calculations combined with Hubbard U corrections for correlated Fe-d electrons. It is found that the vacancy formation energies are lowered in the presence of Fe, indicating an easier destruction of the graphene sheet. Due to strong chemical interactions between Fe clusters and vacancies, a complex distribution of magnetic moments appear on the distorted Fe clusters which results in reduced averaged magnetic moments compared to the free clusters. In addition to that, we have calculated spin-dipole moments and magnetic anisotropy energies. The calculated spin-dipole moments arising from anisotropic spin density distributions vary between positive and negative values, yielding increased or decreased effective moments. Depending on the cluster geometry, the easy axis of magnetization of the Fe clusters shows in-plane or out-of-plane behavior.

Nuclear spin circular dichroism

International Nuclear Information System (INIS)

Vaara, Juha; Rizzo, Antonio; Kauczor, Joanna; Norman, Patrick; Coriani, Sonia

2014-01-01

Recent years have witnessed a growing interest in magneto-optic spectroscopy techniques that use nuclear magnetization as the source of the magnetic field. Here we present a formulation of magnetic circular dichroism (CD) due to magnetically polarized nuclei, nuclear spin-induced CD (NSCD), in molecules. The NSCD ellipticity and nuclear spin-induced optical rotation (NSOR) angle correspond to the real and imaginary parts, respectively, of (complex) quadratic response functions involving the dynamic second-order interaction of the electron system with the linearly polarized light beam, as well as the static magnetic hyperfine interaction. Using the complex polarization propagator framework, NSCD and NSOR signals are obtained at frequencies in the vicinity of optical excitations. Hartree-Fock and density-functional theory calculations on relatively small model systems, ethene, benzene, and 1,4-benzoquinone, demonstrate the feasibility of the method for obtaining relatively strong nuclear spin-induced ellipticity and optical rotation signals. Comparison of the proton and carbon-13 signals of ethanol reveals that these resonant phenomena facilitate chemical resolution between non-equivalent nuclei in magneto-optic spectra

Nuclear spin and isospin excitations

International Nuclear Information System (INIS)

Osterfeld, F.

1992-01-01

A review is given of our present knowledge of collective spin-isospin excitations in nuclei. Most of this knowledge comes from intermediate-energy charge-exchange reactions and from inelastic electron- and proton-scattering experiments. The nuclear-spin dynamics is governed by the spin-isospin-dependent two-nucleon interaction in the medium. This interaction gives rise to collective spin modes such as the giant Gamow-Teller resonances. An interesting phenomenon is that the measured total Gamow-Teller transition strength in the resonance region is much less than a model-independent sum rule predicts. Two physically different mechanisms have been discussed to explain this so-called quenching of the total Gamow-Teller strength: coupling to subnuclear degrees of freedom in the form of Δ-isobar excitation and ordinary nuclear configuration mixing. Both detailed nuclear structure calculations and extensive analyses of the scattering data suggest that the nuclear configuration mixing effect is the more important quenching mechanism, although subnuclear degrees of freedom cannot be ruled out. The quenching phenomenon occurs for nuclear-spin excitations at low excitation energies (ω∼10--20 MeV) and small-momentum transfers (q≤0.5 fm -1 ). A completely opposite effect is anticipated in the high (ω,q)-transfer region (0≤ω≤500 MeV, 0.5≤q≤3 fm -1 ). The nuclear spin-isospin response might be enhanced due to the attractive pion field inside the nucleus. Charge-exchange reactions at GeV incident energies have been used to study the quasifree peak region and the Δ-resonance region. An interesting result of these experiments is that the Δ excitation in the nucleus is shifted downwards in energy relative to the Δ excitation of the free proton

Spin-spin interactions of electrons and also of nucleons create atomic molecular and nuclear structures

International Nuclear Information System (INIS)

Kaliambos, L.A.

2008-01-01

Fundamental interactions of spinning electrons at an interelectron separation less than 578.8 fm yield attractive electromagnetic forces with S = 0 creating vibrations under a motional emf. They explain the indistinguishability of electrons and give a vibration energy able for calculating the ground-state energies of many-electron atoms without using any perturbative approximation. Such forces create two-electron orbitals able to account for the exclusion principal and the mechanism of covalent bonds. In the outer subshells of atoms the penetrating orbitals interact also as pair-pair systems and deform drastically the probability densities of the quantum mechanical electron clouds. Such a dynamics of deformation removes the degeneracy and leads to the deviation from the shell scheme. However in the interior of atoms the large nuclear charge leads to a spherically symmetric potential with non-interacting pairs for creating shells of degenerate states giving an accurate explanation of the X-ray lines. On the other hand, considerable charge distributions in nucleons as multiples of 2e/3 and - e/3 determined by the magnetic moments, interact for creating the nuclear structure with p-n bonds. Such spin-spin interactions show that the dominant concept of the untisymmetric wave function for fermions is inapplicable not only in the simple p-n, p-p, and n-n systems but also in the LS coupling of atoms in which the electrons interact from different quantum states giving either S = 0 or S = l. (author)

Current-induced damping of nanosized quantum moments in the presence of spin-orbit interaction

Science.gov (United States)

Mahfouzi, Farzad; Kioussis, Nicholas

2017-05-01

Motivated by the need to understand current-induced magnetization dynamics at the nanoscale, we have developed a formalism, within the framework of Keldysh Green function approach, to study the current-induced dynamics of a ferromagnetic (FM) nanoisland overlayer on a spin-orbit-coupling (SOC) Rashba plane. In contrast to the commonly employed classical micromagnetic LLG simulations the magnetic moments of the FM are treated quantum mechanically. We obtain the density matrix of the whole system consisting of conduction electrons entangled with the local magnetic moments and calculate the effective damping rate of the FM. We investigate two opposite limiting regimes of FM dynamics: (1) The precessional regime where the magnetic anisotropy energy (MAE) and precessional frequency are smaller than the exchange interactions and (2) the local spin-flip regime where the MAE and precessional frequency are comparable to the exchange interactions. In the former case, we show that due to the finite size of the FM domain, the "Gilbert damping" does not diverge in the ballistic electron transport regime, in sharp contrast to Kambersky's breathing Fermi surface theory for damping in metallic FMs. In the latter case, we show that above a critical bias the excited conduction electrons can switch the local spin moments resulting in demagnetization and reversal of the magnetization. Furthermore, our calculations show that the bias-induced antidamping efficiency in the local spin-flip regime is much higher than that in the rotational excitation regime.

The zero-moment half metal: How could it change spin electronics?

International Nuclear Information System (INIS)

Betto, Davide; Rode, Karsten; Thiyagarajah, Naganivetha; Lau, Yong-Chang; Borisov, Kiril; Atcheson, Gwenael; Stamenov, Plamen; Coey, J. M. D.; Žic, Mario; Archer, Thomas

2016-01-01

The Heusler compound Mn_2Ru_xGa (MRG) may well be the first compensated half metal. Here, the structural, magnetic and transport properties of thin films of MRG are discussed. There is evidence of half-metallicity up to x = 0.7, and compensation of the two Mn sublattice moments is observed at specific compositions and temperatures, leading to a zero-moment half metal. There are potential benefits for using such films with perpendicular anisotropy for spin-torque magnetic tunnel junctions and oscillators, such as low critical current, high tunnel magnetoresistance ratio, insensitivity to external fields and resonance frequency in the THz range.

International Conference on Spin Observables of Nuclear Probes

CERN Document Server

Goodman, Charles; Walker, George; Spin Observables of Nuclear Probes

1988-01-01

The proceedings of the "International Conference on Spin Observables of Nuclear Probes" are presented in this volume. This conference was held in Telluride, Colorado, March 14 -17, 1988, and was the fourth in the Telluride series of nuclear physics conferences. A continuing theme in the Telluride conference series has been the complementarity of various intermediate-energy projectiles for elucidating the nucleon-nucleon interaction and nuclear structure. Earlier conferences have contributed significantly to an understanding of spin currents in nuclei, in particular the distribution of Gamow-Teller strength using charge-exchange reactions. The previous conference on "Antinucleon and Nucleon Nucleus Interactions" compared nuclear information from tra­ tional probes to recent results from antinucleon reactions. The 1988 conference on Spin Observables of Nuclear Probes, put special emphasis on spin observables and brought together experts using spin information to probe nuclear structure. Spin observabl...

Repetitive readout of a single electronic spin via quantum logic with nuclear spin ancillae.

Science.gov (United States)

Jiang, L; Hodges, J S; Maze, J R; Maurer, P; Taylor, J M; Cory, D G; Hemmer, P R; Walsworth, R L; Yacoby, A; Zibrov, A S; Lukin, M D

2009-10-09

Robust measurement of single quantum bits plays a key role in the realization of quantum computation and communication as well as in quantum metrology and sensing. We have implemented a method for the improved readout of single electronic spin qubits in solid-state systems. The method makes use of quantum logic operations on a system consisting of a single electronic spin and several proximal nuclear spin ancillae in order to repetitively readout the state of the electronic spin. Using coherent manipulation of a single nitrogen vacancy center in room-temperature diamond, full quantum control of an electronic-nuclear system consisting of up to three spins was achieved. We took advantage of a single nuclear-spin memory in order to obtain a 10-fold enhancement in the signal amplitude of the electronic spin readout. We also present a two-level, concatenated procedure to improve the readout by use of a pair of nuclear spin ancillae, an important step toward the realization of robust quantum information processors using electronic- and nuclear-spin qubits. Our technique can be used to improve the sensitivity and speed of spin-based nanoscale diamond magnetometers.

Relationship Between Magnitude of Applied Spin Recovery Moment and Ensuing Number of Recovery Turns

Science.gov (United States)

Anglin, Ernie L.

1967-01-01

An analytical study has been made to investigate the relationship between the magnitude of the applied spin recovery moment and the ensuing number of turns made during recovery from a developed spin with a view toward determining how to interpolate or extrapolate spin recovery results with regard to determining the amount of control required for a satisfactory recovery. Five configurations were used which are considered to be representative of modern airplanes: a delta-wing fighter, a stub-wing research vehicle, a boostglide configuration, a supersonic trainer, and a sweptback-wing fighter. The results obtained indicate that there is a direct relationship between the magnitude of the applied spin recovery moments and the ensuing number of recovery turns made and that this relationship can be expressed in either simple multiplicative or exponential form. Either type of relationship was adequate for interpolating or extrapolating to predict turns required for recovery with satisfactory accuracy for configurations having relatively steady recovery motions. Any two recoveries from the same developed spin condition can be used as a basis for the predicted results provided these recoveries are obtained with the same ratio of recovery control deflections. No such predictive method can be expected to give satisfactory results for oscillatory recoveries.

Selective coupling of individual electron and nuclear spins with integrated all-spin coherence protection

Science.gov (United States)

Terletska, Hanna; Dobrovitski, Viatcheslav

2015-03-01

The electron spin of the NV center in diamond is a promising platform for spin sensing. Applying the dynamical decoupling, the NV electron spin can be used to detect the individual weakly coupled carbon-13 nuclear spins in diamond and employ them for small-scale quantum information processing. However, the nuclear spins within this approach remain unprotected from decoherence, which ultimately limits the detection and restricts the fidelity of the quantum operation. Here we investigate possible schemes for combining the resonant decoupling on the NV spin with the decoherence protection of the nuclear spins. Considering several schemes based on pulse and continuous-wave decoupling, we study how the joint electron-nuclear spin dynamics is affected. We identify regimes where the all-spin coherence protection improves the detection and manipulation. We also discuss potential applications of the all-spin decoupling for detecting spins outside diamond, with the purpose of implementing the nanoscale NMR. This work was supported by the US Department of Energy Basic Energy Sciences (Contract No. DE-AC02-07CH11358).

Nuclear spin cooling by electric dipole spin resonance and coherent population trapping

Science.gov (United States)

Li, Ai-Xian; Duan, Su-Qing; Zhang, Wei

2017-09-01

Nuclear spin fluctuation suppression is a key issue in preserving electron coherence for quantum information/computation. We propose an efficient way of nuclear spin cooling in semiconductor quantum dots (QDs) by the coherent population trapping (CPT) and the electric dipole spin resonance (EDSR) induced by optical fields and ac electric fields. The EDSR can enhance the spin flip-flop rate and may bring out bistability under certain conditions. By tuning the optical fields, we can avoid the EDSR induced bistability and obtain highly polarized nuclear spin state, which results in long electron coherence time. With the help of CPT and EDSR, an enhancement of 1500 times of the electron coherence time can been obtained after a 500 ns preparation time.

Laser-spectroscopy measurements of 72-96Kr spins, moments and charge radii

International Nuclear Information System (INIS)

Keim, M.

1995-01-01

The spins, moments and radii of krypton isotopes have been investigated by collinear fast-beam laser spectroscopy in combination with ultra-sensitive collisional ionization detection. The sequence of isotopes under study ranges from the neutron-deficient N=Z=36 isotope 72 Kr to the neutron-rich 96 Kr (N=60). The mean-square charge radii in the neighbourhood of the N=50 neutron-shell closure exhibit a pronounced shell effect which has recently been explained in the framework of relativistic mean-field theory. The results for the neutron-deficient nuclei are related to the shape coexistence of strongly prolate and near-spherical states which is known from nuclear spectroscopy. Here, an inversion of the odd-even staggering is observed below the neutron number N=45. The neutron-rich transitional nuclei are influenced by the N=56 subshell closure. In contrast to the N=60 isotones 97 Rb, 98 Sr and 100 Zr, the new isotope 96 Kr is not strongly deformed. ((orig.))

Nuclear Alignment in Projectile Fragmentation as a Tool for Moment Measurements

International Nuclear Information System (INIS)

Georgiev, G.; Matea, I.; Oliveira Santos, F. de; Lewitowicz, M.; Daugas, J.M.; Belier, G.; Goutte, H.; Meot, V.; Roig, O.; Hass, M.; Baby, L.T.; Goldring, G.; Astabatyan, R.; Lukyanov, S.; Penionzhkevich, Yu.E.; Balabanski, D.L.; Borremans, D.; Himpe, P.; Neyens, G.; Sawicka, M.

2004-01-01

The application of the Time Dependent Perturbed Angular Distribution (TDPAD) method to study isomeric states produced and oriented in projectile-fragmentation reactions provides the opportunity to perform nuclear-moment measurements in a wide range of neutron-rich nuclei, unaccessible by other means. An absolute necessity for the application of the TDPAD technique is a spin-aligned ensemble of nuclei. The preliminary results from a recent application of this method on 61mFe and 54mFe at GANIL, Caen, France showed that a significant increase of the amount of the observed alignment, compared to our previous measurement on 67mNi and 69mCu, can be obtained. Some experimental details, concerning the conservation of the reaction obtained alignment, are discussed

Quantum computation with nuclear spins in quantum dots

International Nuclear Information System (INIS)

Christ, H.

2008-01-01

The role of nuclear spins for quantum information processing in quantum dots is theoretically investigated in this thesis. Building on the established fact that the most strongly coupled environment for the potential electron spin quantum bit are the surrounding lattice nuclear spins interacting via the hyperfine interaction, we turn this vice into a virtue by designing schemes for harnessing this strong coupling. In this perspective, the ensemble of nuclear spins can be considered an asset, suitable for an active role in quantum information processing due to its intrinsic long coherence times. We present experimentally feasible protocols for the polarization, i.e. initialization, of the nuclear spins and a quantitative solution to our derived master equation. The polarization limiting destructive interference effects, caused by the collective nature of the nuclear coupling to the electron spin, are studied in detail. Efficient ways of mitigating these constraints are presented, demonstrating that highly polarized nuclear ensembles in quantum dots are feasible. At high, but not perfect, polarization of the nuclei the evolution of an electron spin in contact with the spin bath can be efficiently studied by means of a truncation of the Hilbert space. It is shown that the electron spin can function as a mediator of universal quantum gates for collective nuclear spin qubits, yielding a promising architecture for quantum information processing. Furthermore, we show that at high polarization the hyperfine interaction of electron and nuclear spins resembles the celebrated Jaynes-Cummings model of quantum optics. This result opens the door for transfer of knowledge from the mature field of quantum computation with atoms and photons. Additionally, tailored specifically for the quantum dot environment, we propose a novel scheme for the generation of highly squeezed collective nuclear states. Finally we demonstrate that even an unprepared completely mixed nuclear spin

Quantum computation with nuclear spins in quantum dots

Energy Technology Data Exchange (ETDEWEB)

Christ, H.

2008-01-24

The role of nuclear spins for quantum information processing in quantum dots is theoretically investigated in this thesis. Building on the established fact that the most strongly coupled environment for the potential electron spin quantum bit are the surrounding lattice nuclear spins interacting via the hyperfine interaction, we turn this vice into a virtue by designing schemes for harnessing this strong coupling. In this perspective, the ensemble of nuclear spins can be considered an asset, suitable for an active role in quantum information processing due to its intrinsic long coherence times. We present experimentally feasible protocols for the polarization, i.e. initialization, of the nuclear spins and a quantitative solution to our derived master equation. The polarization limiting destructive interference effects, caused by the collective nature of the nuclear coupling to the electron spin, are studied in detail. Efficient ways of mitigating these constraints are presented, demonstrating that highly polarized nuclear ensembles in quantum dots are feasible. At high, but not perfect, polarization of the nuclei the evolution of an electron spin in contact with the spin bath can be efficiently studied by means of a truncation of the Hilbert space. It is shown that the electron spin can function as a mediator of universal quantum gates for collective nuclear spin qubits, yielding a promising architecture for quantum information processing. Furthermore, we show that at high polarization the hyperfine interaction of electron and nuclear spins resembles the celebrated Jaynes-Cummings model of quantum optics. This result opens the door for transfer of knowledge from the mature field of quantum computation with atoms and photons. Additionally, tailored specifically for the quantum dot environment, we propose a novel scheme for the generation of highly squeezed collective nuclear states. Finally we demonstrate that even an unprepared completely mixed nuclear spin

The Deuteron Spin-dependent Structure Function $g^{d}_1$ and its First Moment

CERN Document Server

Alexakhin, V.Yu.; Alexeev, G.D.; Alexeev, M.; Amoroso, A.; Balestra, F.; Ball, J.; Barth, J.; Baum, G.; Becker, M.; Bedfer, Y.; Bernet, C.; Bertini, R.; Bettinelli, M.; Birsa, R.; Bisplinghoff, J.; Bordalo, P.; Bradamante, F.; Bressan, A.; Brona, G.; Burtin, E.; Bussa, M.P.; Bytchkov, V.N.; Chapiro, A.; Cicuttin, A.; Colantoni, M.; Colavita, A.A.; Costa, S.; Crespo, M.L.; d'Hose, N.; Dalla Torre, S.; Das, S.; Dasgupta, S.S.; De Masi, R.; Dedek, N.; Demchenko, D.; Denisov, O.Yu.; Dhara, L.; Diaz, V.; Dinkelbach, A.M.; Donskov, S.V.; Dorofeev, V.A.; Doshita, N.; Duic, V.; Dunnweber, W.; Efremov, A.; Eversheim, P.D.; Eyrich, W.; Faessler, M.; Fauland, P.; Ferrero, A.; Ferrero, L.; Finger, M.; M. Finger jr.; Fischer, H.; Franz, J.; Friedrich, J.M.; Frolov, V.; Garfagnini, R.; Gautheron, F.; Gavrichtchouk, O.P.; Gerassimov, S.; Geyer, R.; Giorgi, M.; Gobbo, B.; Goertz, S.; Gorin, A.M.; Grajek, O.A.; Grasso, A.; Grube, B.; Guskov, A.; Haas, F.; Hannappel, J.; von Harrach, D.; Hasegawa, T.; Hedicke, S.; Heinsius, F.H.; Hermann, R.; Hess, C.; Hinterberger, F.; von Hodenberg, M.; Horikawa, N.; Horikawa, S.; Horn, I.; Ilgner, C.; Ioukaev, A.I.; Ivanchin, I.; Ivanov, O.; Iwata, T.; Jahn, R.; Janata, A.; Joosten, R.; Jouravlev, N.I.; Kabuss, E.; Kang, D.; Ketzer, B.; Khaustov, G.V.; Khokhlov, Yu. A.; Kisselev, Yu.; Klein, F.; Klimaszewski, K.; Koblitz, S.; Koivuniemi, J.H.; Kolosov, V.N.; Komissarov, E.V.; Kondo, K.; Konigsmann, K.; Konorov, I.; Konstantinov, V.F.; Korentchenko, A.S.; Korzenev, A.; Kotzinian, A.M.; Koutchinski, N.A.; Kouznetsov, O.; Kowalik, K.; Kramer, D.; Kravchuk, N.P.; Krivokhizhin, G.V.; Kroumchtein, Z.V.; Kubart, J.; Kuhn, R.; Kukhtin, V.; Kunne, F.; Kurek, K.; Ladygin, M.E.; Lamanna, M.; Le Goff, J.M.; Leberig, M.; Lednev, A.A.; Lehmann, A.; Lichtenstadt, J.; Liska, T.; Ludwig, I.; Maggiora, A.; Maggiora, M.; Magnon, A.; Mallot, G.K.; Marchand, C.; Marroncle, J.; Martin, A.; Marzec, J.; Masek, L.; Massmann, F.; Matsuda, T.; Matthia, D.; Maximov, A.N.; Meyer, W.; Mielech, A.; Mikhailov, Yu. V.; Moinester, M.A.; Nagel, T.; Nahle, O.; Nassalski, J.; Neliba, S.; Neyret, D.P.; Nikolaenko, V.I.; Nikolaev, K.; Nozdrin, A.A.; Obraztsov, V.F.; Olshevsky, A.G.; Ostrick, M.; Padee, A.; Pagano, P.; Panebianco, S.; Panzieri, D.; Paul, S.; Peshekhonov, D.V.; Peshekhonov, V.D.; Piragino, G.; Platchkov, S.; Pochodzalla, J.; Polak, J.; Polyakov, V.A.; Pontecorvo, G.; Popov, A.A.; Pretz, J.; Procureur, S.; Quintans, C.; Ramos, S.; Reicherz, G.; Rondio, E.; Rozhdestvensky, A.M.; Ryabchikov, D.; Samoylenko, V.D.; Sandacz, A.; Santos, H.; Sapozhnikov, M.G.; Savin, I.A.; Schiavon, P.; Schill, C.; Schmitt, L.; Schroeder, W.; Seeharsch, D.; Seimetz, M.; Setter, D.; Shevchenko, O.Yu.; Siebert, H.W.; Silva, L.; Sinha, L.; Sissakian, A.N.; Slunecka, M.; Smirnov, G.I.; Sozzi, F.; Srnka, A.; Stinzing, F.; Stolarski, M.; Sugonyaev, V.P.; Sulc, M.; Sulej, R.; Tchalishev, V.V.; Tessaro, S.; Tessarotto, F.; Teufel, A.; Tkatchev, L.G.; Trippel, S.; Venugopal, G.; Virius, M.; Vlassov, N.V.; Webb, R.; Weise, E.; Weitzel, Q.; Windmolders, R.; Wislicki, W.; Zaremba, K.; Zavertyaev, M.; Zemlyanichkina, E.; Zhao, J.; Zvyagin, A.

2007-01-01

We present a measurement of the deuteron spin-dependent structure function g^d_1 based on the data collected by the COMPASS experiment at CERN during the years 2002-2004. The data provide an accurate evaluation for \\Gamma^d_1, the first moment of g^d_1(x), and for the matrix element of the singlet axial current, a_0. The results of QCD fits in the next to leading order (NLO) on all g1 deep inelastic scattering data are also presented. They provide two solutions with the gluon spin distribution function \\Delta_G positive or negative, which describe the data equally well. In both cases, at Q^2 = 3(GeV/c)^2 the first moment of \\Delta G is found to be of the order of 0:2 - 0:3 in absolute value.

Magnetic moments of the spin-(3)/(2) doubly heavy baryons

Energy Technology Data Exchange (ETDEWEB)

Meng, Lu; Li, Hao-Song [Peking University, School of Physics and State Key Laboratory of Nuclear Physics and Technology, Beijing (China); Liu, Zhan-Wei [Lanzhou University, School of Physical Science and Technology, Lanzhou (China); Zhu, Shi-Lin [Peking University, School of Physics and State Key Laboratory of Nuclear Physics and Technology, Beijing (China); Collaborative Innovation Center of Quantum Matter, Beijing (China)

2017-12-15

In this work, we investigate the chiral corrections to the magnetic moments of the spin-(3)/(2) doubly charmed baryons systematically up to next-to-next-to-leading order with the heavy baryon chiral perturbation theory. The numerical results are given up to next-to-leading order: μ{sub Ξ}{sup {sub *}{sub +}{sub +{sub c{sub c}}}} = 2.61μ{sub N}, μ{sub Ξ}{sup {sub *}{sub +{sub c{sub c}}}} = -0.18μ{sub N}, μ{sub Ω}{sup {sub *}{sub +{sub c{sub c}}}} = 0.17μ{sub N}. As a by-product, we have also calculated the magnetic moments of the spin-(3)/(2) doubly bottom baryons and charmed bottom baryons: μ{sub Ξ}{sup {sub *}{sub 0{sub b{sub b}}}} = 2.83μ{sub N}, μ{sub Ξ}{sup {sub *}{sub -{sub b{sub b}}}} = -1.33μ{sub N}, μ{sub Ω}{sup {sub *}{sub -{sub b{sub b}}}} = -1.54μ{sub N}, μ{sub Ξ}{sup {sub *}{sub +{sub b{sub c}}}} = 3.22μ{sub N}, μ{sub Ξ}{sup {sub *}{sub 0{sub b{sub c}}}} = -0.84μ{sub N}, μ{sub Ω}{sup {sub *}{sub 0{sub b{sub c}}}} = -1.09μ{sub N}. (orig.)

An endohedral fullerene-based nuclear spin quantum computer

International Nuclear Information System (INIS)

Ju Chenyong; Suter, Dieter; Du Jiangfeng

2011-01-01

We propose a new scalable quantum computer architecture based on endohedral fullerene molecules. Qubits are encoded in the nuclear spins of the endohedral atoms, which posses even longer coherence times than the electron spins which are used as the qubits in previous proposals. To address the individual qubits, we use the hyperfine interaction, which distinguishes two modes (active and passive) of the nuclear spin. Two-qubit quantum gates are effectively implemented by employing the electronic dipolar interaction between adjacent molecules. The electron spins also assist in the qubit initialization and readout. Our architecture should be significantly easier to implement than earlier proposals for spin-based quantum computers, such as the concept of Kane [B.E. Kane, Nature 393 (1998) 133]. - Research highlights: → We propose an endohedral fullerene-based scalable quantum computer architecture. → Qubits are encoded on nuclear spins, while electron spins serve as auxiliaries. → Nuclear spins are individually addressed using the hyperfine interaction. → Two-qubit gates are implemented through the medium of electron spins.

The electron-spin--nuclear-spin interaction studied by polarized neutron scattering.

Science.gov (United States)

Stuhrmann, Heinrich B

2007-11-01

Dynamic nuclear spin polarization (DNP) is mediated by the dipolar interaction of paramagnetic centres with nuclear spins. This process is most likely to occur near paramagnetic centres at an angle close to 45 degrees with respect to the direction of the external magnetic field. The resulting distribution of polarized nuclear spins leads to an anisotropy of the polarized neutron scattering pattern, even with randomly oriented radical molecules. The corresponding cross section of polarized coherent neutron scattering in terms of a multipole expansion is derived for radical molecules in solution. An application using data of time-resolved polarized neutron scattering from an organic chromium(V) molecule is tested.

Electronic Spin Storage in an Electrically Readable Nuclear Spin Memory with a Lifetime >100 Seconds

Science.gov (United States)

McCamey, D. R.; Van Tol, J.; Morley, G. W.; Boehme, C.

2010-12-01

Electron spins are strong candidates with which to implement spintronics because they are both mobile and able to be manipulated. The relatively short lifetimes of electron spins, however, present a problem for the long-term storage of spin information. We demonstrated an ensemble nuclear spin memory in phosphorous-doped silicon, which can be read out electrically and has a lifetime exceeding 100 seconds. The electronic spin information can be mapped onto and stored in the nuclear spin of the phosphorus donors, and the nuclear spins can then be repetitively read out electrically for time periods that exceed the electron spin lifetime. We discuss how this memory can be used in conjunction with other silicon spintronic devices.

Controlling a nuclear spin in a nanodiamond

Science.gov (United States)

Knowles, Helena S.; Kara, Dhiren M.; Atatüre, Mete

2017-09-01

The sensing capability of a single optically bright electronic spin in diamond can be enhanced by making use of proximal dark nuclei as ancillary spins. Such systems, so far realized only in bulk diamond, can provide orders of magnitude higher sensitivity and spectral resolution in the case of magnetic sensing, as well as improved readout fidelity and state storage time in quantum information schemes. Nanodiamonds offer opportunities for scanning and embedded nanoscale probes, yet electronic-nuclear spin complexes have so far remained inaccessible. Here, we demonstrate coherent control of a 13C nuclear spin located 4 Å from a nitrogen-vacancy center in a nanodiamond and show coherent exchange between the two components of this hybrid spin system. We extract a free precession time T2* of 26 μ s for the nuclear spin, which exceeds the bare-electron free-precession time in nanodiamond by two orders of magnitude.

The classical equations of motion for a spinning point particle with charge and magnetic moment

International Nuclear Information System (INIS)

Rowe, E.G.P.; Rowe, G.T.

1987-01-01

The classical, special relativistic equations of motion are derived for a spinning point particle interacting with the electromagnetic field through its charge and magnetic moment. Radiation reaction is included. The energy tensors for the particle and for the field are developed as well-defined distributions; consequently no infinities appear. The magnitude of spin and the rest mass are conserved. (orig.)

Moment methods with effective nuclear Hamiltonians; calculations of radial moments

International Nuclear Information System (INIS)

Belehrad, R.H.

1981-02-01

A truncated orthogonal polynomial expansion is used to evaluate the expectation value of the radial moments of the one-body density of nuclei. The expansion contains the configuration moments, , , and 2 >, where R/sup (k)/ is the operator for the k-th power of the radial coordinate r, and H is the effective nuclear Hamiltonian which is the sum of the relative kinetic energy operator and the Bruckner G matrix. Configuration moments are calculated using trace reduction formulae where the proton and neutron orbitals are treated separately in order to find expectation values of good total isospin. The operator averages are taken over many-body shell model states in the harmonic oscillator basis where all particles are active and single-particle orbitals through six major shells are included. The radial moment expectation values are calculated for the nuclei 16 O, 40 Ca, and 58 Ni and find that is usually the largest term in the expansion giving a large model space dependence to the results. For each of the 3 nuclei, a model space is found which gives the desired rms radius and then we find that the other 5 lowest moments compare favorably with other theoretical predictions. Finally, we use a method of Gordon (5) to employ the lowest 6 radial moment expectation values in the calculation of elastic electron scattering from these nuclei. For low to moderate momentum transfer, the results compare favorably with the experimental data

The electron-nuclear spin system in (In,Ga)As quantum dots

International Nuclear Information System (INIS)

Auer, Thomas

2008-01-01

For a long time, the nuclear spins in quantum dots were virtually ignored. It was thought that the interaction strength was so small that the interaction between the nuclei and electrons could only be observed under very specific optical pumping conditions. Then, in the pursuit of long living electron spins as a building block for quantum information storage and processing, their destructive action on the lifetime of the electron spin became apparent. The nuclear spin system increasingly gained the attention of the quantum dot community. It seemed that the randomly oriented, fluctuating nuclear spins can only be counteracted by strong magnetic fields suppressing the depolarising effect of the random nuclear spin fluctuation fields on a single electron spin. Gradually, however, the work done thirty years before on the electron-nuclear spin system in bulk semiconductors attracted the notice of scientists again. Some of the old experiments could be performed with quantum dots as well. It could be shown that the nuclear spins in quantum dots may well be polarised by optical orientation and that their action is not always destructive at all. The nuclear spins in quantum dots are increasingly used in order to create and tailor a specific environment for a single electron in a quantum dot. In this way quantum dots contain their own ''nuclear nanomagnet''. This might be the future of the studies on the electron-nuclear spin system. The aim of this work is to shed some more light on the complex interdependent system formed of an electron spin and the nuclear spin ensemble in quantum dots. The effects are manifold, often unexpected, sometimes miraculous. Nevertheless, I believe that this work is another tiny step towards the understanding of this challenging system. I have shown that the randomly polarised nuclear spin system always affects the electron spin of a single electron in quantum dots. Further we have seen, however, that the nuclear spin system can easily be

Shell structure of potassium isotopes deduced from their magnetic moments

CERN Document Server

Papuga, J.; Kreim, K; Barbieri, C; Blaum, K; De Rydt, M; Duguet, T; Garcia Ruiz, R F; Heylen, H; Kowalska, M; Neugart, R; Neyens, G; Nortershauser, W; Rajabali, M M; Sanchez, R; Smirnova, N; Soma, V; Yordanov, D T

2014-09-29

$\\textbf{Background:}$ Ground-state spins and magnetic moments are sensitive to the nuclear wave function, thus they are powerful probes to study the nuclear structure of isotopes far from stability. \\\\ \\\\ $\\textbf{Purpose:}$ Extend our knowledge about the evolution of the $1/2^+$ and $3/2^+$ states for K isotopes beyond the $N = 28$ shell gap. \\\\ \\\\ $\\textbf{Method:}$ High-resolution collinear laser spectroscopy on bunched atomic beams. \\\\ \\\\ $\\textbf{Results:}$ From measured hyperfine structure spectra of K isotopes, nuclear spins and magnetic moments of the ground states were obtained for isotopes from $N = 19$ up to $N = 32$. In order to draw conclusions about the composition of the wave functions and the occupation of the levels, the experimental data were compared to shell-model calculations using SDPF-NR and SDPF-U effective interactions. In addition, a detailed discussion about the evolution of the gap between proton $1d_{3/2}$ and $2s_{1/2}$ in the shell model and $\\textit{ab initio}$ framework is al...

Robust techniques for polarization and detection of nuclear spin ensembles

Science.gov (United States)

Scheuer, Jochen; Schwartz, Ilai; Müller, Samuel; Chen, Qiong; Dhand, Ish; Plenio, Martin B.; Naydenov, Boris; Jelezko, Fedor

2017-11-01

Highly sensitive nuclear spin detection is crucial in many scientific areas including nuclear magnetic resonance spectroscopy, magnetic resonance imaging (MRI), and quantum computing. The tiny thermal nuclear spin polarization represents a major obstacle towards this goal which may be overcome by dynamic nuclear spin polarization (DNP) methods. The latter often rely on the transfer of the thermally polarized electron spins to nearby nuclear spins, which is limited by the Boltzmann distribution of the former. Here we utilize microwave dressed states to transfer the high (>92 % ) nonequilibrium electron spin polarization of a single nitrogen-vacancy center (NV) induced by short laser pulses to the surrounding 13C carbon nuclear spins. The NV is repeatedly repolarized optically, thus providing an effectively infinite polarization reservoir. A saturation of the polarization of the nearby nuclear spins is achieved, which is confirmed by the decay of the polarization transfer signal and shows an excellent agreement with theoretical simulations. Hereby we introduce the polarization readout by polarization inversion method as a quantitative magnetization measure of the nuclear spin bath, which allows us to observe by ensemble averaging macroscopically hidden polarization dynamics like Landau-Zener-Stückelberg oscillations. Moreover, we show that using the integrated solid effect both for single- and double-quantum transitions nuclear spin polarization can be achieved even when the static magnetic field is not aligned along the NV's crystal axis. This opens a path for the application of our DNP technique to spins in and outside of nanodiamonds, enabling their application as MRI tracers. Furthermore, the methods reported here can be applied to other solid state systems where a central electron spin is coupled to a nuclear spin bath, e.g., phosphor donors in silicon and color centers in silicon carbide.

Nuclear spin conversion in formaldehyde

OpenAIRE

Chapovsky, Pavel L.

2000-01-01

Theoretical model of the nuclear spin conversion in formaldehyde (H2CO) has been developed. The conversion is governed by the intramolecular spin-rotation mixing of molecular ortho and para states. The rate of conversion has been found equal 1.4*10^{-4}~1/s*Torr. Temperature dependence of the spin conversion has been predicted to be weak in the wide temperature range T=200-900 K.

Dependence of nuclear moments of inertia on the triaxial parameter

International Nuclear Information System (INIS)

Helgesson, J.; Hamamoto, Ikuko

1989-01-01

The dependence of nuclear moments of inertia on the triaxial parameter (γ-variable) is investigated including both the Belyaev term and the Migdal term. The obtained dependence is compared with that of hydrodynamical moments of inertia and other moments of inertia used conventionally. (orig.)

Spin squeezing of atomic ensembles via nuclear-electronic spin entanglement

DEFF Research Database (Denmark)

Fernholz, Thomas; Krauter, Hanna; Jensen, Kasper

2008-01-01

quantum limit for quantum memory experiments and applications in quantum metrology and is thus a complementary alternative to spin squeezing obtained via inter-atom entanglement. Squeezing of the collective spin is verified by quantum state tomography.......We demonstrate spin squeezing in a room temperature ensemble of 1012 Cesium atoms using their internal structure, where the necessary entanglement is created between nuclear and electronic spins of each individual atom. This state provides improvement in measurement sensitivity beyond the standard...

Nuclear spin-off

International Nuclear Information System (INIS)

1981-11-01

This booklet gives examples of 'nuclear spin off', from research programmes carried out for the UKAEA, under the following headings; non destructive testing; tribology; environmental protection; flow measurement; material sciences; mechanical engineering; marine services; biochemical technology; electronic instrumentation. (U.K.)

Stabilization of the Electron-Nuclear Spin Orientation in Quantum Dots by the Nuclear Quadrupole Interaction

Science.gov (United States)

Dzhioev, R. I.; Korenev, V. L.

2007-07-01

The nuclear quadrupole interaction eliminates the restrictions imposed by hyperfine interaction on the spin coherence of an electron and nuclei in a quantum dot. The strain-induced nuclear quadrupole interaction suppresses the nuclear spin flip and makes possible the zero-field dynamic nuclear polarization in self-organized InP/InGaP quantum dots. The direction of the effective nuclear magnetic field is fixed in space, thus quenching the magnetic depolarization of the electron spin in the quantum dot. The quadrupole interaction suppresses the zero-field electron spin decoherence also for the case of nonpolarized nuclei. These results provide a new vision of the role of the nuclear quadrupole interaction in nanostructures: it elongates the spin memory of the electron-nuclear system.

Generating highly polarized nuclear spins in solution using dynamic nuclear polarization

DEFF Research Database (Denmark)

Wolber, J.; Ellner, F.; Fridlund, B.

2004-01-01

A method to generate strongly polarized nuclear spins in solution has been developed, using Dynamic Nuclear Polarization (DNP) at a temperature of 1.2K, and at a field of 3.354T, corresponding to an electron spin resonance frequency of 94GHz. Trityl radicals are used to directly polarize 13C...... and other low-γ nuclei. Subsequent to the DNP process, the solid sample is dissolved rapidly with a warm solvent to create a solution of molecules with highly polarized nuclear spins. Two main applications are proposed: high-resolution liquid state NMR with enhanced sensitivity, and the use...

Core Polarization and Tensor Coupling Effects on Magnetic Moments of Hypernuclei

International Nuclear Information System (INIS)

Jiang-Ming, Yao; Jie, Meng; Hong-Feng, Lü; Greg, Hillhouse

2008-01-01

Effects of core polarization and tensor coupling on the magnetic moments in Λ 13 C, Λ 17 O, and Λ 41 Ca Λ-hypernuclei are studied by employing the Dirac equation with scalar, vector and tensor potentials. It is found that the effect of core polarization on the magnetic moments is suppressed by Λ tensor coupling. The Λ tensor potential reduces the spin-orbit splitting of p Λ states considerably. However, almost the same magnetic moments are obtained using the hyperon wavefunction obtained via the Dirac equation either with or without the A tensor potential in the electromagnetic current vertex. The deviations of magnetic moments for p Λ states from the Schmidt values are found to increase with nuclear mass number. (nuclear physics)

Nuclear Spin Nanomagnet in an Optically Excited Quantum Dot

Science.gov (United States)

Korenev, V. L.

2007-12-01

Linearly polarized light tuned slightly below the optical transition of the negatively charged exciton (trion) in a single quantum dot causes the spontaneous nuclear spin polarization (self-polarization) at a level close to 100%. The effective magnetic field of spin-polarized nuclei shifts the optical transition energy close to resonance with photon energy. The resonantly enhanced Overhauser effect sustains the stability of the nuclear self-polarization even in the absence of spin polarization of the quantum dot electron. As a result the optically selected single quantum dot represents a tiny magnet with the ferromagnetic ordering of nuclear spins—the nuclear spin nanomagnet.

Spin precession of a particle with an electric dipole moment: contributions from classical electrodynamics and from the Thomas effect

International Nuclear Information System (INIS)

Silenko, Alexander J

2015-01-01

The new derivation of the equation of the spin precession is given for a particle possessing electric and magnetic dipole moments. Contributions from classical electrodynamics and from the Thomas effect are explicitly separated. A fully covariant approach is used. The final equation is expressed in a very simple form in terms of the fields in the instantaneously accompanying frame. The Lorentz transformations of the electric and magnetic dipole moments and of the spin are derived from basic equations of classical electrodynamics. For this purpose, the Maxwell equations in matter are used and the result is confirmed by other methods. An antisymmetric four-tensor is correctly constructed from the electric and magnetic dipole moments. (article)

Nuclear Spins in Quantum Dots

NARCIS (Netherlands)

Erlingsson, S.I.

2003-01-01

The main theme of this thesis is the hyperfine interaction between the many lattice nuclear spins and electron spins localized in GaAs quantum dots. This interaction is an intrinsic property of the material. Despite the fact that this interaction is rather weak, it can, as shown in this thesis,

Vanishing current hysteresis under competing nuclear spin pumping processes in a quadruplet spin-blockaded double quantum dot

Energy Technology Data Exchange (ETDEWEB)

Amaha, S., E-mail: s-amaha@riken.jp [Quantum Spin Information Project, Japan Science and Technology Agency, ICORP, 3-1, Morinosato Wakamiya, Atsugi-shi, Kanagawa 243-0198 (Japan); Quantum Functional System Research Group, RIKEN Center for Emergent Matter Science, RIKEN, 3-1 Wako-shi, Saitama 351-0198 (Japan); Hatano, T. [Quantum Spin Information Project, Japan Science and Technology Agency, ICORP, 3-1, Morinosato Wakamiya, Atsugi-shi, Kanagawa 243-0198 (Japan); Department of Physics, Tohoku University, Sendai-shi, Miyagi 980-8578 (Japan); Tarucha, S. [Quantum Spin Information Project, Japan Science and Technology Agency, ICORP, 3-1, Morinosato Wakamiya, Atsugi-shi, Kanagawa 243-0198 (Japan); Quantum Functional System Research Group, RIKEN Center for Emergent Matter Science, RIKEN, 3-1 Wako-shi, Saitama 351-0198 (Japan); Department of Applied Physics, School of Engineering, University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); Gupta, J. A.; Austing, D. G. [National Research Council of Canada, M50, Montreal Road, Ottawa, Ontario K1A 0R6 (Canada)

2015-04-27

We investigate nuclear spin pumping with five-electron quadruplet spin states in a spin-blockaded weakly coupled vertical double quantum dot device. Two types of hysteretic steps in the leakage current are observed on sweeping the magnetic field and are associated with bidirectional polarization of nuclear spin. Properties of the steps are understood in terms of bias-voltage-dependent conditions for the mixing of quadruplet and doublet spin states by the hyperfine interaction. The hysteretic steps vanish when up- and down-nuclear spin pumping processes are in close competition.

Polarization transfer from polarized nuclear spin to μ- spin in muonic atom

International Nuclear Information System (INIS)

Kuno, Yoshitaka; Nagamine, Kanetada; Yamazaki, Toshimitsu.

1987-02-01

A theoretical study of polarization transfer from an initially-polarized nuclear spin to a μ - spin in a muonic atom is given. The switching of the hyperfine interaction at excited muonic states as well as at the ground 1s state is taken into account. The upper state of hyperfine doublet at the muonic 1s state is considered to proceed down to the lower state. It is found that as the hyperfine interaction becomes effective at higher excited muonic orbitals, a less extent of polarization is transferred from the nuclear spin to the μ - spin. The theoretical values obtained are compared with the recent experiment of μ - repolarization in a polarized 209 Bi target. (author)

Inelastic electron tunneling spectroscopy of a single nuclear spin.

Science.gov (United States)

Delgado, F; Fernández-Rossier, J

2011-08-12

Detection of a single nuclear spin constitutes an outstanding problem in different fields of physics such as quantum computing or magnetic imaging. Here we show that the energy levels of a single nuclear spin can be measured by means of inelastic electron tunneling spectroscopy (IETS). We consider two different systems, a magnetic adatom probed with scanning tunneling microscopy and a single Bi dopant in a silicon nanotransistor. We find that the hyperfine coupling opens new transport channels which can be resolved at experimentally accessible temperatures. Our simulations evince that IETS yields information about the occupations of the nuclear spin states, paving the way towards transport-detected single nuclear spin resonance.

Nuclear orientation experiments on the magnetic moments of europium and gadolinium nuclei

International Nuclear Information System (INIS)

Berg, F.G. van den.

1984-01-01

In this thesis, experimental results on the ground state nuclear magnetic moments of europium and gadolinium isotopes are presented. The nuclear orientation experiments were performed on europium and gadolinium nuclei embedded in several host lattices. Attention is paid to the hyperfine interactions of the ions. Nuclear moments are discussed in the context of nuclear shell model. The theoretical framework is described for nuclear structure and low temperature nuclear orientation. Furthermore, the experimental techniques, the technical arrangement of the orientation apparatus, the methods for radiative detection and the use of nuclear orientation thermometry are described. (Auth.)

Nuclear Spin Relaxation

Indian Academy of Sciences (India)

IAS Admin

ments have shown that in some cases the nuclear spin systems may be held in special configurations called .... these methods have been commercialized, and used for clinical trials, in which hyperpolarized NMR is used to .... symmetric under exchange, meaning that exchanging the two nuclei leaves the state unchanged.

Magnetic moments of high spin rotational states in 158Dy and 164Dy+

International Nuclear Information System (INIS)

Seiler-Clark, G.

1983-09-01

For the study of their magnetic moments yrast states in 158 Dy and 164 Dy were excited via the multiple-Coulomb excitation by a 4.7 MeV/u 208 Pb beam. Hereby especially the question was of interest, how the one-particle effects in the nuclear structure in the region of the backbending anomaly in 158 Dy take effects on the g-factors of the high spin states in this region. The particle-γ angular correlations perturbed in the transient magnetic field during the passing of the excited Dy ions through a thin magnetized iron foil were measured. By the selective position-sensitive detection of Dy recoil ions and Pb projectiles under forward angles it was possible to determine additionally to the g-factors in the backbending region also g-factors in the spin region I 158 Dy and 164 Dy by detection of the particle-γ correlations precessing in the static hyperfine field after implantation in iron. The static hyperfine field was at the 4 + state in 164 Dy determined to B (Dy,Fe) = 245+-25 T. The g-factors were determined by comparison of the experimental results with calculations of the perturbed angular correlations by time-differential regarding of the population and de-excitation of the yrast states as well as by precession and hyperfine-relaxation effects during the flight of the Dy ions in the vacuum. (orig./HSI) [de

Two-stage nuclear refrigeration with enhanced nuclear moments

International Nuclear Information System (INIS)

Hunik, R.

1979-01-01

Experiments are described in which an enhanced nuclear system is used as a precoolant for a nuclear demagnetisation stage. The results show the promising advantages of such a system in those circumstances for which a large cooling power is required at extremely low temperatures. A theoretical review of nuclear enhancement at the microscopic level and its macroscopic thermodynamical consequences is given. The experimental equipment for the implementation of the nuclear enhanced refrigeration method is described and the experiments on two-stage nuclear demagnetisation are discussed. With the nuclear enhanced system PrCu 6 the author could precool a nuclear stage of indium in a magnetic field of 6 T down to temperatures below 10 mK; this resulted in temperature below 1 mK after demagnetisation of the indium. It is demonstrated that the interaction energy between the nuclear moments in an enhanced nuclear system can exceed the nuclear dipolar interaction. Several experiments are described on pulsed nuclear magnetic resonance, as utilised for thermometry purposes. It is shown that platinum NMR-thermometry gives very satisfactory results around 1 mK. The results of experiments on nuclear orientation of radioactive nuclei, e.g. the brute force polarisation of 95 NbPt and 60 CoCu, are presented, some of which are of major importance for the thermometry in the milli-Kelvin region. (Auth.)

Searches for the electron electric dipole moment and nuclear anapole moments in solids

International Nuclear Information System (INIS)

Mukhamedjanov, T.N.; Sushkov, O.P.; Cadogan, J.M.; Dzuba, V.A.

2004-01-01

Full text: We consider effects caused by the electron electric dipole moment (EDM) in gadolinium garnets. Our estimates show that the experimental studies of these effects could improve the current upper limit on the electron EDM by several orders of magnitude. We suggest a consistent theoretical model and perform calculations of observable effects in gadolinium gallium garnet and gadolinium iron garnet. It is also possible to probe for nuclear anapole moments in a solid state experiment. We suggest such NMR-type experiment and perform estimates of the expected results

Polarization of spin-1 particles without an anomalous magnetic moment in a uniform magnetic field

OpenAIRE

Silenko, Alexander J.

2008-01-01

The polarization operator projections onto four directions remain unchanged for spin-1 particles without an anomalous magnetic moment in a uniform magnetic field. The approximate conservation of the polarization operator projections onto the horizontal axes of the cylindrical coordinate system takes place.

Inhomogeneous nuclear spin polarization induced by helicity-modulated optical excitation of fluorine-bound electron spins in ZnSe

Science.gov (United States)

Heisterkamp, F.; Greilich, A.; Zhukov, E. A.; Kirstein, E.; Kazimierczuk, T.; Korenev, V. L.; Yugova, I. A.; Yakovlev, D. R.; Pawlis, A.; Bayer, M.

2015-12-01

Optically induced nuclear spin polarization in a fluorine-doped ZnSe epilayer is studied by time-resolved Kerr rotation using resonant excitation of donor-bound excitons. Excitation with helicity-modulated laser pulses results in a transverse nuclear spin polarization, which is detected as a change of the Larmor precession frequency of the donor-bound electron spins. The frequency shift in dependence on the transverse magnetic field exhibits a pronounced dispersion-like shape with resonances at the fields of nuclear magnetic resonance of the constituent zinc and selenium isotopes. It is studied as a function of external parameters, particularly of constant and radio frequency external magnetic fields. The width of the resonance and its shape indicate a strong spatial inhomogeneity of the nuclear spin polarization in the vicinity of a fluorine donor. A mechanism of optically induced nuclear spin polarization is suggested based on the concept of resonant nuclear spin cooling driven by the inhomogeneous Knight field of the donor-bound electron.

Spin-spin cross-relaxation of optically-excited rare-earth ions in crystals

International Nuclear Information System (INIS)

Otto, F.W.; D'Amato, F.X.; Hahn, E.L.; Lukas, M.

1986-01-01

A laser saturation grating experiment is applied for the measurement of electron hyperfine state spin orientation diffusion among Tm +2 impurity ion hyperfine ground states in SrF 2 . A strong laser pulse at λ 1 produces a spatial grating of excited spin states followed by a probe at λ 2 . The probe transmission intensity is to assess diffusion of non-equilibrium spin population into regions not excited by the pulse at λ 1 . In a second experiment, a field sweep laser hole burning method enables measurement of Pr +3 optical ion hyperfine coupling of optical ground states to the reservoir of F nuclear moments in LaF 3 by level crossing. A related procedure with external RF resonance sweep excitation maps out the nuclear Zeeman-electric quadrupole coupled spectrum of Pr +3 over a wide range by monitoring laser beam transmission absorption

Electron and nuclear spin system polarization in semiconductors by light

Energy Technology Data Exchange (ETDEWEB)

Zakharchenya, B; Flejsher, V

1981-02-01

Discussed are the principles of optical electron spin orientation, dynamic polarization and cooling of nuclear spin systems in optical electron orientation, and behavioural characteristics of bound electron and nuclear spin systems of a semiconductor in the optical orientation situation.

Electron and nuclear spin system polarization in semiconductors by light

International Nuclear Information System (INIS)

Zakharchenya, B.; Flejsher, V.

1981-01-01

Discussed are the principles of optical electron spin orientation, dynamic polarization and cooling of nuclear spin systems in optical electron orientation, and behavioural characteristics of bound electron and nuclear spin systems of a semiconductor in the optical orientation situation. (J.P.)

Gross shell structure at high spin in heavy nuclei

International Nuclear Information System (INIS)

Deleplanque, Marie-Agnes; Frauendorf, Stefan; Pashkevich, Vitaly V.; Chu, S.Y.; Unzhakova, Anja

2003-01-01

Experimental nuclear moments of inertia at high spins along the yrast line have been determined systematically and found to differ from the rigid-body values. The difference is attributed to shell effect and these have been calculated microscopically. The data and quantal calculations are interpreted by means of the semiclassical Periodic Orbit Theory. From this new perspective, features in the moments of inertia as a function of neutron number and spin, as well as their relation to the shell energies can be understood. Gross shell effects persist up to the highest angular momenta observed

Reinterpretation of the ''relativistic mass'' correction to the spin magnetic moment of a moving particle

International Nuclear Information System (INIS)

Hegstrom, R.A.; Lhuillier, C.

1977-01-01

Starting from a classical covariant equation of motion for the spin of a particle moving in a homogeneous electromagnetic field (the Bargmann-Michel-Telegdi equation), we show that the ''relativistic mass'' correction to the electron spin magnetic moment, which has been obtained previously from relativistic quantum-mechanical treatments of the Zeeman effect, may be reinterpreted as the combination of three classical effects: (i) the difference in time scales in the electron rest frame vis-a-vis the lab frame, (ii) the Lorentz transformation of the magnetic field between the two frames, and (iii) the Thomas precession of the electron spin due to the acceleration of the electron produced by the magnetic field

Nuclear moments of radioactive nuclei. Final report

International Nuclear Information System (INIS)

Greenlees, G.W.

1985-01-01

An unsuccessful attempt was made to study nuclear moments of radioactive nuclear using laser spectroscopy. Although preliminary tests had indicated a sensitivity sufficient to observe signals of fluxes less than one atom/s no resonance fluorescence was detected. Activity measurements showed several hundred nuclei per second were in the beam; therefore it was postulated that, due to the the reactivity of the 126 Ba and sodium used, contaminants were the probable source of negative results. 3 refs., 2 figs

All-electric control of donor nuclear spin qubits in silicon

Science.gov (United States)

Sigillito, Anthony J.; Tyryshkin, Alexei M.; Schenkel, Thomas; Houck, Andrew A.; Lyon, Stephen A.

2017-10-01

The electronic and nuclear spin degrees of freedom of donor impurities in silicon form ultra-coherent two-level systems that are potentially useful for applications in quantum information and are intrinsically compatible with industrial semiconductor processing. However, because of their smaller gyromagnetic ratios, nuclear spins are more difficult to manipulate than electron spins and are often considered too slow for quantum information processing. Moreover, although alternating current magnetic fields are the most natural choice to drive spin transitions and implement quantum gates, they are difficult to confine spatially to the level of a single donor, thus requiring alternative approaches. In recent years, schemes for all-electrical control of donor spin qubits have been proposed but no experimental demonstrations have been reported yet. Here, we demonstrate a scalable all-electric method for controlling neutral 31P and 75As donor nuclear spins in silicon. Using coplanar photonic bandgap resonators, we drive Rabi oscillations on nuclear spins exclusively using electric fields by employing the donor-bound electron as a quantum transducer, much in the spirit of recent works with single-molecule magnets. The electric field confinement leads to major advantages such as low power requirements, higher qubit densities and faster gate times. Additionally, this approach makes it possible to drive nuclear spin qubits either at their resonance frequency or at its first subharmonic, thus reducing device bandwidth requirements. Double quantum transitions can be driven as well, providing easy access to the full computational manifold of our system and making it convenient to implement nuclear spin-based qudits using 75As donors.

Spin-off technologies developed through nuclear activities

International Nuclear Information System (INIS)

1993-01-01

Given the changing role of government research establishments and the interest in maximizing return on capital and intellectual investment, determining the best way to apply or ''spin-off'' technologies from the nuclear field into other industrial and commercial sectors is of increasing concern. This study by the OECD Nuclear Energy Agency draws on expertise from numerous countries to determine what the spin-offs are, where they come from, and how they can best be fostered. It looks both at the results and process of spin-offs, and helps decision-makers in government and project leaders and managers in industry to maximize their benefits. (author)

Modulation Algorithms for Manipulating Nuclear Spin States

OpenAIRE

Liu, Boyang; Zhang, Ming; Dai, Hong-Yi

2013-01-01

We exploit the impact of exact frequency modulation on transition time of steering nuclear spin states from theoretical point of view. 1-stage and 2-stage Frequency-Amplitude-Phase modulation (FAPM) algorithms are proposed in contrast with 1-stage and 3-stage Amplitude-Phase modulation (APM) algorithms. The sufficient conditions are further present for transiting nuclear spin states within the specified time by these four modulation algorithms. It is demonstrated that transition time performa...

Spin microscope based on optically detected magnetic resonance

Science.gov (United States)

Berman, Gennady P.; Chernobrod, Boris M.

2007-12-11

The invention relates to scanning magnetic microscope which has a photoluminescent nanoprobe implanted in the tip apex of an atomic force microscope (AFM), a scanning tunneling microscope (STM) or a near-field scanning optical microscope (NSOM) and exhibits optically detected magnetic resonance (ODMR) in the vicinity of unpaired electron spins or nuclear magnetic moments in the sample material. The described spin microscope has demonstrated nanoscale lateral resolution and single spin sensitivity for the AFM and STM embodiments.

Dephasing due to Nuclear Spins in Large-Amplitude Electric Dipole Spin Resonance.

Science.gov (United States)

Chesi, Stefano; Yang, Li-Ping; Loss, Daniel

2016-02-12

We analyze effects of the hyperfine interaction on electric dipole spin resonance when the amplitude of the quantum-dot motion becomes comparable or larger than the quantum dot's size. Away from the well-known small-drive regime, the important role played by transverse nuclear fluctuations leads to a Gaussian decay with characteristic dependence on drive strength and detuning. A characterization of spin-flip gate fidelity, in the presence of such additional drive-dependent dephasing, shows that vanishingly small errors can still be achieved at sufficiently large amplitudes. Based on our theory, we analyze recent electric dipole spin resonance experiments relying on spin-orbit interactions or the slanting field of a micromagnet. We find that such experiments are already in a regime with significant effects of transverse nuclear fluctuations and the form of decay of the Rabi oscillations can be reproduced well by our theory.

First Measurement of the Atomic Electric Dipole Moment of (225)Ra.

Science.gov (United States)

Parker, R H; Dietrich, M R; Kalita, M R; Lemke, N D; Bailey, K G; Bishof, M; Greene, J P; Holt, R J; Korsch, W; Lu, Z-T; Mueller, P; O'Connor, T P; Singh, J T

2015-06-12

The radioactive radium-225 ((225)Ra) atom is a favorable case to search for a permanent electric dipole moment. Because of its strong nuclear octupole deformation and large atomic mass, (225)Ra is particularly sensitive to interactions in the nuclear medium that violate both time-reversal symmetry and parity. We have developed a cold-atom technique to study the spin precession of (225)Ra atoms held in an optical dipole trap, and demonstrated the principle of this method by completing the first measurement of its atomic electric dipole moment, reaching an upper limit of |d((225)Ra)|<5.0×10(-22)  e cm (95% confidence).

Spin polarized states in strongly asymmetric nuclear matter

International Nuclear Information System (INIS)

Isayev, A.A.; Yang, J.

2004-01-01

The possibility of appearance of spin polarized states in strongly asymmetric nuclear matter is analyzed within the framework of a Fermi liquid theory with the Skyrme effective interaction. The zero temperature dependence of the neutron and proton spin polarization parameters as functions of density is found for SLy4 and SLy5 effective forces. It is shown that at some critical density strongly asymmetric nuclear matter undergoes a phase transition to the state with the oppositely directed spins of neutrons and protons while the state with the same direction of spins does not appear. In comparison with neutron matter, even small admixture of protons strongly decreases the threshold density of spin instability. It is clarified that protons become totally polarized within a very narrow density domain while the density profile of the neutron spin polarization parameter is characterized by the appearance of long tails near the transition density

Study of Nuclear Moments and Mean Square Charge Radii by Collinear Fast-Beam Laser Spectroscopy

CERN Multimedia

2002-01-01

The collinear fast-beam laser technique is used to measure atomic hyperfine structures and isotope shifts of unstable nuclides produced at ISOLDE. This gives access to basic nuclear ground-state and isomeric-state properties such as spins, magnetic dipole and electric quadrupole moments, and the variation of the nuclear mean square charge radius within a sequence of isotopes. \\\\ \\\\ Among the various techniques used for this purpose, the present approach is of greatest versatility, due to the direct use of the beams from the isotope separator. Their phase-space properties are exploited to achieve high sensitivity and resolution. The optical spectra of neutral atoms are made accessible by converting the ion beams into fast atomic beams. This is accomplished in the charge-exchange cell which is kept at variable potential ($\\pm$10~kV) for Doppler-tuning of the effective laser wavelength. The basic optical resolution of 10$^{-8}$ requires a 10$^{-5}$ stability of the 60~kV main acceleration voltage and low energy ...

Relaxation of nuclear spin on holes in semiconductors

International Nuclear Information System (INIS)

Gr'ncharova, E.I.; Perel', V.I.

1977-01-01

The longitudienal relaxation time T 1 of nuclear spins due to dipole-dipole interaction with holes in semiconductors is calculated. Expressions for T 1 in cubic and uniaxial semiconductors are obtained for non-degenerate and degenerate cases. On the basis of comparison with available experimental data for silicon the agreement with the theoretical results is obtained. It is demonstrated that in uniaxial semiconductors the time of relaxation on holes for a nuclear spin directed along the c axis is considerably greater than that for a spin in the normal direction

Gordon Conference on Nuclear Research

International Nuclear Information System (INIS)

Austin, S.M.

1983-09-01

Session topics were: quarks and nuclear physics; anomalons and anti-protons; the independent particle structure of nuclei; relativistic descriptions of nuclear structure and scattering; nuclear structure at high excitation; advances in nuclear astrophysics; properties of nuclear material; the earliest moments of the universe; and pions and spin excitations in nuclei

Spin, quadrupole moment, and deformation of the magnetic-rotational band head in Pb193

Science.gov (United States)

Balabanski, D. L.; Ionescu-Bujor, M.; Iordachescu, A.; Bazzacco, D.; Brandolini, F.; Bucurescu, D.; Chmel, S.; Danchev, M.; de Poli, M.; Georgiev, G.; Haas, H.; Hübel, H.; Marginean, N.; Menegazzo, R.; Neyens, G.; Pavan, P.; Rossi Alvarez, C.; Ur, C. A.; Vyvey, K.; Frauendorf, S.

2011-01-01

The spectroscopic quadrupole moment of the T1/2=9.4(5) ns isomer in Pb193 at an excitation energy Eex=(2585+x) keV is measured by the time-differential perturbed angular distribution method as |Qs|=2.6(3) e b. Spin and parity Iπ=27/2- are assigned to it based on angular distribution measurements. This state is the band head of a magnetic-rotational band, described by the 1i13/2 subshell with the (3s1/2-21h9/21i13/2)11- proton excitation. The pairing-plus-quadrupole tilted-axis cranking calculations reproduce the measured quadrupole moment with a moderate oblate deformation ɛ2=-0.11, similar to that of the 11-proton intruder states, which nuclei in the region. This is the first direct measurement of a quadrupole moment and thus of the deformation of a magnetic-rotational band head.

Antiferromagnetic spin phase transition in nuclear matter with effective Gogny interaction

International Nuclear Information System (INIS)

Isayev, A.A.; Yang, J.

2004-01-01

The possibility of ferromagnetic and antiferromagnetic phase transitions in symmetric nuclear matter is analyzed within the framework of a Fermi liquid theory with the effective Gogny interaction. It is shown that at some critical density nuclear matter with the D1S effective force undergoes a phase transition to the antiferromagnetic spin state (opposite directions of neutron and proton spins). The self-consistent equations of spin polarized nuclear matter with the D1S force have no solutions corresponding to ferromagnetic spin ordering (the same direction of neutron and proton spins) and, hence, the ferromagnetic transition does not appear. The dependence of the antiferromagnetic spin polarization parameter as a function of density is found at zero temperature

Nuclear high-spin data for A = 174, 176 and 184

Energy Technology Data Exchange (ETDEWEB)

Junde, Huo [Jilin Univ. (China). Dept. of Physics

1996-06-01

Nuclear high-spin data are important in the frontier areas of nuclear structure physics. The information on A = 174, 176 and 184 mass chains from various reaction experiments together with their adopted high-spin levels and gamma transition properties are presented and discussed. High-spin data for A = 174, 176 and 184 mass chains were evaluated in 1995.

Atomic-Scale Nuclear Spin Imaging Using Quantum-Assisted Sensors in Diamond

Directory of Open Access Journals (Sweden)

A. Ajoy

2015-01-01

Full Text Available Nuclear spin imaging at the atomic level is essential for the understanding of fundamental biological phenomena and for applications such as drug discovery. The advent of novel nanoscale sensors promises to achieve the long-standing goal of single-protein, high spatial-resolution structure determination under ambient conditions. In particular, quantum sensors based on the spin-dependent photoluminescence of nitrogen-vacancy (NV centers in diamond have recently been used to detect nanoscale ensembles of external nuclear spins. While NV sensitivity is approaching single-spin levels, extracting relevant information from a very complex structure is a further challenge since it requires not only the ability to sense the magnetic field of an isolated nuclear spin but also to achieve atomic-scale spatial resolution. Here, we propose a method that, by exploiting the coupling of the NV center to an intrinsic quantum memory associated with the nitrogen nuclear spin, can reach a tenfold improvement in spatial resolution, down to atomic scales. The spatial resolution enhancement is achieved through coherent control of the sensor spin, which creates a dynamic frequency filter selecting only a few nuclear spins at a time. We propose and analyze a protocol that would allow not only sensing individual spins in a complex biomolecule, but also unraveling couplings among them, thus elucidating local characteristics of the molecule structure.

Predicting superdeformed rotational band-head spin in A ∼ 190 mass region using variable moment of inertia model

International Nuclear Information System (INIS)

Uma, V.S.; Goel, Alpana; Yadav, Archana; Jain, A.K.

2016-01-01

The band-head spin (I 0 ) of superdeformed (SD) rotational bands in A ∼ 190 mass region is predicted using the variable moment of inertia (VMI) model for 66 SD rotational bands. The superdeformed rotational bands exhibited considerably good rotational property and rigid behaviour. The transition energies were dependent on the prescribed band-head spins. The ratio of transition energies over spin Eγ/ 2 I (RTEOS) vs. angular momentum (I) have confirmed the rigid behaviour, provided the band-head spin value is assigned correctly. There is a good agreement between the calculated and the observed transition energies. This method gives a very comprehensive interpretation for spin assignment of SD rotational bands which could help in designing future experiments for SD bands. (author)

Thermodynamics of Rh nuclear spins calculated by exact diagonalization

DEFF Research Database (Denmark)

Lefmann, K.; Ipsen, J.; Rasmussen, F.B.

2000-01-01

We have employed the method of exact diagonalization to obtain the full-energy spectrum of a cluster of 16 Rh nuclear spins, having dipolar and RK interactions between first and second nearest neighbours only. We have used this to calculate the nuclear spin entropy, and our results at both positi...

Perturbation of nuclear spin polarizations in solid state NMR of nitroxide-doped samples by magic-angle spinning without microwaves

Energy Technology Data Exchange (ETDEWEB)

Thurber, Kent R., E-mail: thurberk@niddk.nih.gov; Tycko, Robert [Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-0520 (United States)

2014-05-14

We report solid state {sup 13}C and {sup 1}H nuclear magnetic resonance (NMR) experiments with magic-angle spinning (MAS) on frozen solutions containing nitroxide-based paramagnetic dopants that indicate significant perturbations of nuclear spin polarizations without microwave irradiation. At temperatures near 25 K, {sup 1}H and cross-polarized {sup 13}C NMR signals from {sup 15}N,{sup 13}C-labeled L-alanine in trinitroxide-doped glycerol/water are reduced by factors as large as six compared to signals from samples without nitroxide doping. Without MAS or at temperatures near 100 K, differences between signals with and without nitroxide doping are much smaller. We attribute most of the reduction of NMR signals under MAS near 25 K to nuclear spin depolarization through the cross-effect dynamic nuclear polarization mechanism, in which three-spin flips drive nuclear polarizations toward equilibrium with spin polarization differences between electron pairs. When T{sub 1e} is sufficiently long relative to the MAS rotation period, the distribution of electron spin polarization across the nitroxide electron paramagnetic resonance lineshape can be very different from the corresponding distribution in a static sample at thermal equilibrium, leading to the observed effects. We describe three-spin and 3000-spin calculations that qualitatively reproduce the experimental observations.

Perturbation of nuclear spin polarizations in solid state NMR of nitroxide-doped samples by magic-angle spinning without microwaves

International Nuclear Information System (INIS)

Thurber, Kent R.; Tycko, Robert

2014-01-01

We report solid state 13 C and 1 H nuclear magnetic resonance (NMR) experiments with magic-angle spinning (MAS) on frozen solutions containing nitroxide-based paramagnetic dopants that indicate significant perturbations of nuclear spin polarizations without microwave irradiation. At temperatures near 25 K, 1 H and cross-polarized 13 C NMR signals from 15 N, 13 C-labeled L-alanine in trinitroxide-doped glycerol/water are reduced by factors as large as six compared to signals from samples without nitroxide doping. Without MAS or at temperatures near 100 K, differences between signals with and without nitroxide doping are much smaller. We attribute most of the reduction of NMR signals under MAS near 25 K to nuclear spin depolarization through the cross-effect dynamic nuclear polarization mechanism, in which three-spin flips drive nuclear polarizations toward equilibrium with spin polarization differences between electron pairs. When T 1e is sufficiently long relative to the MAS rotation period, the distribution of electron spin polarization across the nitroxide electron paramagnetic resonance lineshape can be very different from the corresponding distribution in a static sample at thermal equilibrium, leading to the observed effects. We describe three-spin and 3000-spin calculations that qualitatively reproduce the experimental observations

Perturbation of nuclear spin polarizations in solid state NMR of nitroxide-doped samples by magic-angle spinning without microwaves.

Science.gov (United States)

Thurber, Kent R; Tycko, Robert

2014-05-14

We report solid state (13)C and (1)H nuclear magnetic resonance (NMR) experiments with magic-angle spinning (MAS) on frozen solutions containing nitroxide-based paramagnetic dopants that indicate significant perturbations of nuclear spin polarizations without microwave irradiation. At temperatures near 25 K, (1)H and cross-polarized (13)C NMR signals from (15)N,(13)C-labeled L-alanine in trinitroxide-doped glycerol/water are reduced by factors as large as six compared to signals from samples without nitroxide doping. Without MAS or at temperatures near 100 K, differences between signals with and without nitroxide doping are much smaller. We attribute most of the reduction of NMR signals under MAS near 25 K to nuclear spin depolarization through the cross-effect dynamic nuclear polarization mechanism, in which three-spin flips drive nuclear polarizations toward equilibrium with spin polarization differences between electron pairs. When T1e is sufficiently long relative to the MAS rotation period, the distribution of electron spin polarization across the nitroxide electron paramagnetic resonance lineshape can be very different from the corresponding distribution in a static sample at thermal equilibrium, leading to the observed effects. We describe three-spin and 3000-spin calculations that qualitatively reproduce the experimental observations.

Voltage switching technique for detecting nuclear spin polarization in a quantum dot

International Nuclear Information System (INIS)

Takahashi, Ryo; Kono, Kimitoshi; Tarucha, Seigo; Ono, Keiji

2010-01-01

We have introduced a source-drain voltage switching technique for studying nuclear spins in a vertical double quantum dot. Switching the source-drain voltage between the spin-blockade state and the zero-bias Coulomb blockade state can tune the energy difference between the spin singlet and triplet, and effectively turn on/off the hyperfine interaction. Since the change in the nuclear spin state affects the source-drain current, nuclear spin properties can only be detected by transport measurement. Using this technique, we have succeeded in measuring the timescale of nuclear spin depolarization. Furthermore, combining this technique and an RF ac magnetic field, we successfully detected continuous-wave NMR signals of 75 As, 69 Ga, and 71 Ga, which are contained in a quantum dot. (author)

Demonstration of a Sensitive Method to Measure Nuclear-Spin-Dependent Parity Violation

Science.gov (United States)

Altuntaş, Emine; Ammon, Jeffrey; Cahn, Sidney B.; DeMille, David

2018-04-01

Nuclear-spin-dependent parity violation (NSD-PV) effects in atoms and molecules arise from Z0 boson exchange between electrons and the nucleus, and from the magnetic interaction between electrons and the parity-violating nuclear anapole moment. We demonstrate measurements of NSD-PV that use an enhancement of the effect in diatomic molecules, here using the test system 138Ba 19. Our sensitivity surpasses that of any previous atomic parity violation measurement. We show that systematic errors can be suppressed to at least the level of the present statistical sensitivity. We measure the matrix element W of the NSD-PV interaction with total uncertainty δ W /(2 π )<0.7 Hz , for each of two configurations where W must have different signs. This sensitivity would be sufficient to measure NSD-PV effects of the size anticipated across a wide range of nuclei including 137Ba in 137BaF, where |W |/(2 π )≈5 Hz is expected.

Polarization of nuclear spins by a cold nanoscale resonator

International Nuclear Information System (INIS)

Butler, Mark C.; Weitekamp, Daniel P.

2011-01-01

A cold nanoscale resonator coupled to a system of nuclear spins can induce spin relaxation. In the low-temperature limit where spin-lattice interactions are ''frozen out,'' spontaneous emission by nuclear spins into a resonant mechanical mode can become the dominant mechanism for cooling the spins to thermal equilibrium with their environment. We provide a theoretical framework for the study of resonator-induced cooling of nuclear spins in this low-temperature regime. Relaxation equations are derived from first principles, in the limit where energy donated by the spins to the resonator is quickly dissipated into the cold bath that damps it. A physical interpretation of the processes contributing to spin polarization is given. For a system of spins that have identical couplings to the resonator, the interaction Hamiltonian conserves spin angular momentum, and the resonator cannot relax the spins to thermal equilibrium unless this symmetry is broken by the spin Hamiltonian. The mechanism by which such a spin system becomes ''trapped'' away from thermal equilibrium can be visualized using a semiclassical model, which shows how an indirect spin-spin interaction arises from the coupling of multiple spins to one resonator. The internal spin Hamiltonian can affect the polarization process in two ways: (1) By modifying the structure of the spin-spin correlations in the energy eigenstates, and (2) by splitting the degeneracy within a manifold of energy eigenstates, so that zero-frequency off-diagonal terms in the density matrix are converted to oscillating coherences. Shifting the frequencies of these coherences sufficiently far from zero suppresses the development of resonator-induced correlations within the manifold during polarization from a totally disordered state. Modification of the spin-spin correlations by means of either mechanism affects the strength of the fluctuating spin dipole that drives the resonator. In the case where product states can be chosen as energy

Optical hyperpolarization of 13C nuclear spins in nanodiamond ensembles

Science.gov (United States)

Chen, Q.; Schwarz, I.; Jelezko, F.; Retzker, A.; Plenio, M. B.

2015-11-01

Dynamical nuclear polarization holds the key for orders of magnitude enhancements of nuclear magnetic resonance signals which, in turn, would enable a wide range of novel applications in biomedical sciences. However, current implementations of DNP require cryogenic temperatures and long times for achieving high polarization. Here we propose and analyze in detail protocols that can achieve rapid hyperpolarization of 13C nuclear spins in randomly oriented ensembles of nanodiamonds at room temperature. Our protocols exploit a combination of optical polarization of electron spins in nitrogen-vacancy centers and the transfer of this polarization to 13C nuclei by means of microwave control to overcome the severe challenges that are posed by the random orientation of the nanodiamonds and their nitrogen-vacancy centers. Specifically, these random orientations result in exceedingly large energy variations of the electron spin levels that render the polarization and coherent control of the nitrogen-vacancy center electron spins as well as the control of their coherent interaction with the surrounding 13C nuclear spins highly inefficient. We address these challenges by a combination of an off-resonant microwave double resonance scheme in conjunction with a realization of the integrated solid effect which, together with adiabatic rotations of external magnetic fields or rotations of nanodiamonds, leads to a protocol that achieves high levels of hyperpolarization of the entire nuclear-spin bath in a randomly oriented ensemble of nanodiamonds even at room temperature. This hyperpolarization together with the long nuclear-spin polarization lifetimes in nanodiamonds and the relatively high density of 13C nuclei has the potential to result in a major signal enhancement in 13C nuclear magnetic resonance imaging and suggests functionalized and hyperpolarized nanodiamonds as a unique probe for molecular imaging both in vitro and in vivo.

Description of the turnover of the dynamical moment of inertia of the superdeformed nuclear state

International Nuclear Information System (INIS)

Yuxin Liu; Jiangang Song; Hong-zhou Sun; Jia-jun Wang; En-guang Zhao

1998-01-01

We propose in this paper an approach to describe the dynamical moment of inertia of superdeformed nuclear states in the spirit of variable moments of inertia. Both the general changing feature and the turnover of dynamical moments of inertia with rotational frequency are well described in our approach. It indicates that the competition between the angular momentum driving effect and the restraining effect plays a crucial role in determining the dynamical moments of inertia of superdeformed nuclear states. (author)

Statistical methods of spin assignment in compound nuclear reactions

International Nuclear Information System (INIS)

Mach, H.; Johns, M.W.

1984-01-01

Spin assignment to nuclear levels can be obtained from standard in-beam gamma-ray spectroscopy techniques and in the case of compound nuclear reactions can be complemented by statistical methods. These are based on a correlation pattern between level spin and gamma-ray intensities feeding low-lying levels. Three types of intensity and level spin correlations are found suitable for spin assignment: shapes of the excitation functions, ratio of intensity at two beam energies or populated in two different reactions, and feeding distributions. Various empirical attempts are examined and the range of applicability of these methods as well as the limitations associated with them are given. 12 references

Statistical methods of spin assignment in compound nuclear reactions

International Nuclear Information System (INIS)

Mach, H.; Johns, M.W.

1985-01-01

Spin assignment to nuclear levels can be obtained from standard in-beam gamma-ray spectroscopy techniques and in the case of compound nuclear reactions can be complemented by statistical methods. These are based on a correlation pattern between level spin and gamma-ray intensities feeding low-lying levels. Three types of intensity and level spin correlations are found suitable for spin assignment: shapes of the excitation functions, ratio of intensity at two beam energies or populated in two different reactions, and feeding distributions. Various empirical attempts are examined and the range of applicability of these methods as well as the limitations associated with them are given

Nuclear moments from heavy-ion inelastic scattering above the Coulomb barrier

International Nuclear Information System (INIS)

Gross, E.E.

1981-01-01

Use of appropriate theoretical techniques allows the study of the moments of the nuclear charge distribution to be extended above the Coulomb barrier. The investigation of nuclear moments through analysis of differential cross sections is discussed with the aid of several examples: 12 C(70.4 MeV) + 144 146 Nd, importance of multistep effects; 20 Ne(131 MeV) + 208 Pb, large hexadecapole deformation; 12 C(78 MeV) + 194 Pt, asymmetric rotor model; and 22 Ne(93.5 MeV) + 126 Te, mutual excitation. 13 figures, 1 table

Nuclear data for the high-spin community

Energy Technology Data Exchange (ETDEWEB)

Firestone, R B [Lawrence Berkeley Lab., CA (United States); Singh, B [McMaster Univ., Hamilton, ON (Canada). Tandem Accelerator Lab.

1992-08-01

The Isotopes Project at Berkeley is developing the Evaluated High-Spin Data File, a subset of the Evaluated Nuclear Structure Data File (ENSDF). The following products were under development at the time of the conference: eighth edition of the Table of Isotopes, electronic table of isotopes, data bases, nuclear charts, nuclear wallet cards, nuclear CD-ROM, FAX data services, on-line data services.

Stimulated nuclear spin echos and spectral diffusion in glasses

International Nuclear Information System (INIS)

Borges, N.M.; Engelsberg, M.

1984-01-01

Experimental results of stimulated nuclear spin echos decay in glasses are presented. The measurements were performed in B 2 O 3 glasses, at the 23Na and 11 B resonance lines. The data analysis allows the study of Spectral diffusion at an inhomogeneous nuclear magnetic (NMR) resonance line, broadened for a desordered system of nuclear spins. A model is proposed to explain the time constants, and the particular form of the decay. (A.C.A.S.) [pt

Nuclear moments and charge radii of argon isotopes between the neutron-shell closures N=20 and N=28

CERN Document Server

Blaum, K; Lassen, J; Lievens, P; Marinova, K; Neugart, R

2008-01-01

We report the measurement of optical isotope shifts for $^{40-44}\\!$Ar relative to $^{38}$Ar from which changes in the mean square nuclear charge radii across the 1$\\scriptstyle{f}_{7/2}$ neutron shell are deduced. In addition, the hyperfine structure of $^{41\\!}$Ar and $^{43}$Ar yields the spins, magnetic dipole and electric quadrupole moments, in particular the spin $\\,\\scriptstyle\\textrm{I}$ = 5/2 for $\\,^{43}\\!$Ar. The investigations were carried out by fast-beam collinear laser spectroscopy using highly sensitive detection based on optical pumping and state-selective collisional ionization. Mean square charge radii are now known from $^{32}$Ar to $^{46}$Ar, covering sd-shell as well as $\\scriptstyle{f}_{7/2}$-shell nuclei. They are discussed in the framework of spherical SGII Skyrme-type Hartree-Fock calculations, semi-empirically corrected for quadrupole core polarization. The Zamick-Talmi formula excellently describes the charge radii across the $\\scriptstyle{f}_{7/2}$ neutron shell, as it does for the...

A new spin-oriented nuclei facility: POLAREX

Directory of Open Access Journals (Sweden)

Etilé A.

2014-03-01

Full Text Available Using the On-Line Nuclear Orientation method, POLAREX (POLARization of EXotic nuclei is a new facility allowing to study the anisotropic decay of spin-oriented nuclei. Based on the combination of on-line implantation of radioactive nuclei with Low Temperature Nuclear Orientation technique and Nuclear Magnetic Resonance, POLAREX allows to measure nuclear electromagnetic moments and ground-state spins, in the aim to get information about the wave function composition of the nuclear state. Polarized nuclei can also be used to study fundamental interactions involving nuclear β-decay asymmetries. The POLAREX infrastructure will be installed at Accélérateur Linéaire auprés du Tandem d’Orsay in order to study neutron-rich nuclei, some of which have not been studied yet. Will be presented here, all the possibilities of this new facility and a non exhaustive scientific program.

Hanle effect in (In,Ga)As quantum dots: Role of nuclear spin fluctuations

OpenAIRE

Kuznetsova, M. S.; Flisinski, K.; Gerlovin, I. Ya.; Ignatiev, I. V.; Kavokin, K. V.; Verbin, S. Yu.; Yakovlev, D. R.; Reuter, D.; Wieck, A. D.; Bayer, M.

2013-01-01

The role of nuclear spin fluctuations in the dynamic polarization of nuclear spins by electrons is investigated in (In,Ga)As quantum dots. The photoluminescence polarization under circularly polarized optical pumping in transverse magnetic fields (Hanle effect) is studied. A weak additional magnetic field parallel to the optical axis is used to control the efficiency of nuclear spin cooling and the sign of nuclear spin temperature. The shape of the Hanle curve is drastically modified with cha...

High-spin nuclear spectroscopy

International Nuclear Information System (INIS)

Diamond, R.M.

1986-07-01

High-spin spectroscopy is the study of the changes in nuclear structure, properties, and behavior with increasing angular momentum. It involves the complex interplay between collective and single-particle motion, between shape and deformation changes, particle alignments, and changes in the pairing correlations. A review of progress in theory, experimentation, and instrumentation in this field is given

Dynamical nuclear spin polarization induced by electronic current through double quantum dots

International Nuclear Information System (INIS)

Lopez-Monis, Carlos; Platero, Gloria; Inarrea, Jesus

2011-01-01

We analyse electron-spin relaxation in electronic transport through coherently coupled double quantum dots (DQDs) in the spin blockade regime. In particular, we focus on hyperfine (HF) interaction as the spin-relaxation mechanism. We pay special attention to the effect of the dynamical nuclear spin polarization induced by the electronic current on the nuclear environment. We discuss the behaviour of the electronic current and the induced nuclear spin polarization versus an external magnetic field for different HF coupling intensities and interdot tunnelling strengths. We take into account, for each magnetic field, all HF-mediated spin-relaxation processes coming from different opposite spin level approaches. We find that the current as a function of the external magnetic field shows a peak or a dip and that the transition from a current dip to a current peak behaviour is obtained by decreasing the HF coupling or by increasing the interdot tunnelling strength. We give a physical picture in terms of the interplay between the electrons tunnelling out of the DQD and the spin-flip processes due to the nuclear environment.

Measurement of the neutron electric dipole moment: simultaneous spin analysis and preliminary data analysis

International Nuclear Information System (INIS)

Helaine, Victor

2014-01-01

In the framework of the neutron Electric Dipole Moment (nEDM) experiment at the Paul Scherrer Institut (Switzerland), this thesis deals with the development of a new system of spin analysis. The goal here is to simultaneously detect the two spin components of ultracold neutrons in order to increase the number of detected neutrons and therefore lower the nEDM statistical error. Such a system has been designed using Geant4-UCN simulations, built at LPC Caen and then tested as part of the experiment. In parallel to this work, the 2013 nEDM data taken at PSI have been analysed. Finally, methods to recover magnetic observables of first interest to control nEDM systematic errors have been studied and possible improvements are proposed. (author) [fr

Induced spin-accumulation and spin-polarization in a quantum-dot ring by using magnetic quantum dots and Rashba spin-orbit effect

International Nuclear Information System (INIS)

Eslami, L.; Faizabadi, E.

2014-01-01

The effect of magnetic contacts on spin-dependent electron transport and spin-accumulation in a quantum ring, which is threaded by a magnetic flux, is studied. The quantum ring is made up of four quantum dots, where two of them possess magnetic structure and other ones are subjected to the Rashba spin-orbit coupling. The magnetic quantum dots, referred to as magnetic quantum contacts, are connected to two external leads. Two different configurations of magnetic moments of the quantum contacts are considered; the parallel and the anti-parallel ones. When the magnetic moments are parallel, the degeneracy between the transmission coefficients of spin-up and spin-down electrons is lifted and the system can be adjusted to operate as a spin-filter. In addition, the accumulation of spin-up and spin-down electrons in non-magnetic quantum dots are different in the case of parallel magnetic moments. When the intra-dot Coulomb interaction is taken into account, we find that the electron interactions participate in separation between the accumulations of electrons with different spin directions in non-magnetic quantum dots. Furthermore, the spin-accumulation in non-magnetic quantum dots can be tuned in the both parallel and anti-parallel magnetic moments by adjusting the Rashba spin-orbit strength and the magnetic flux. Thus, the quantum ring with magnetic quantum contacts could be utilized to create tunable local magnetic moments which can be used in designing optimized nanodevices.

Effect of the moment-of-inertia variation on Coulomb-nuclear interference in heavy ion scattering

International Nuclear Information System (INIS)

Bolotin, Yu.L.; Gonchar, V.Yu.; Inopin, E.V.; Chekanov, N.A.

1987-01-01

Effect of moment-of-inertia (MI) variation on probabilities of the Coulomb excitation of nucleus rotational states (RS) is investigated. The calculation is performed in the generalized quasiclassical approximation. Cillisions with an aimed parameter equal to 0 and recording of scattered ion at angles close to 180 deg were considered. Effect of MI dependence on angular momentum (AM) on the RS Coulomb excitation probability in the 86 Kr+ 238 U process at 400 MeV 86 Kr has been studied. For small AMs (I < 10), when the MI variation can be neglected, the Coulomb-nuclear interference leads to a marked shift of RS excitation probability maxima. However, with increasing transferred AM the convergence of probabilities conditioned with mutual compensation of phases shift related to the MI variation and Coulomb-nucleus interference, is noted. It is also noted that correct parameters of deformed nuclei extracted from experiments on the Coulomb excitation of high-spin states can be obtained only during simultaneous accountancy of both the Coulomb-nuclear interference and the MI variation of excited nuclei

Nuclear spin dynamics in double quantum dots : Fixed points, transients, and intermittency

NARCIS (Netherlands)

Rudner, M.S.; Koppens, F.H.L.; Folk, J.A.; Vandersypen, L.M.K.; Levitov, L.S.

2011-01-01

Transport through spin-blockaded quantum dots provides a means for electrical control and detection of nuclear spin dynamics in the host material. Although such experiments have become increasingly popular in recent years, interpretation of their results in terms of the underlying nuclear spin

The effect of a neutrino magnetic moment on nuclear excitation processes

International Nuclear Information System (INIS)

Dodd, A.C.; Papageorgiu, E.; Ranfone, S.

1991-01-01

It is shown that the MeV-range neutrinos with a magnetic moment of ≅ 10 -11 Bohr magnetons would excite nuclei, like 12 C, with cross sections comparable to those obtained in the Standard Model. This implies the possibility of improving the present experimental bounds on the magnetic moment of any flavour of neutrinos by one order of magnitude. Such a magnetic moment would also enhance the coherent neutrino-nuclear scattering in low-temperature detectors, enabling them to set comparable limits. (author)

Interfacial tuning of perpendicular magnetic anisotropy and spin magnetic moment in CoFe/Pd multilayers

Energy Technology Data Exchange (ETDEWEB)

Ngo, D.-T., E-mail: ndthe82@gmail.com [Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore 117576 (Singapore); Meng, Z.L. [Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore 117576 (Singapore); Tahmasebi, T. [Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore 117576 (Singapore); Data Storage Institute, A-STAR (Agency for Science Technology and Research), 5 Engineering Drive 1, Singapore 117608 (Singapore); Yu, X. [Singapore Synchrotron Light Source, National University of Singapore, 5 Research Link, Singapore 117603 (Singapore); Thoeng, E. [Singapore Synchrotron Light Source, National University of Singapore, 5 Research Link, Singapore 117603 (Singapore); Department of Physics, National University of Singapore, Singapore 117542 (Singapore); Yeo, L.H. [Department of Physics, National University of Singapore, Singapore 117542 (Singapore); Rusydi, A., E-mail: phyandri@nus.edu.sg [Singapore Synchrotron Light Source, National University of Singapore, 5 Research Link, Singapore 117603 (Singapore); Department of Physics, National University of Singapore, Singapore 117542 (Singapore); Han, G.C [Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore 117576 (Singapore); Teo, K.-L., E-mail: eleteokl@nus.edu.sg [Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore 117576 (Singapore)

2014-01-15

We report on a strong perpendicular magnetic anisotropy in [CoFe 0.4 nm/Pd t]{sub 6} (t=1.0–2.0 nm) multilayers fabricated by DC sputtering in an ultrahigh vacuum chamber. Saturation magnetization, M{sub s}, and uniaxial anisotropy, K{sub u}, of the multilayers decrease with increasing the spacing thickness; with a M{sub s} of 155 emu/cc and a K{sub u} of 1.14×10{sup 5} J/m{sup 3} at a spacing thickness of t=2 nm. X-ray absorption spectroscopy and X-ray magnetic circular dichroism measurements reveal that spin and orbital magnetic moments of Co and Fe in CoFe film decrease as a function of Pd thickness, indicating the major contribution of surface/interfacial magnetism to the magnetic properties of the film. - Highlights: • Strong perpendicular magnetic anisotropy essentially contributed by interfacial anisotropy. • Controllably magnetic properties with low M{sub s}, high K{sub u}, high P. • Interfacial magnetic moments modified by CoFe/Pd interfaces with strong spin–orbit coupling. • Narrow Bloch walls with Néel caps. • Superior magnetic characteristics for spin-torque applications.

Cluster-spin dynamics in a GaMo{sub 4}S{sub 8}-type compound: {sup 27}Al nuclear magnetic resonance study of AlMo{sub 4}S{sub 8}

Energy Technology Data Exchange (ETDEWEB)

Ikeno, R; Nakamura, H; Kohara, T [Graduate School of Material Science, University of Hyogo, Kamigori, Ako-gun, Hyogo 678-1297 (Japan)

2007-01-31

The cluster-spin dynamics of the tetrahedral Mo{sub 4} cluster, involved in AlMo{sub 4}S{sub 8} with a cubic GaMo{sub 4}S{sub 8} type structure, was investigated by NMR of the nonmagnetic {sup 27}Al site located outside the cluster. The nuclear spin-lattice relaxation is described well by the conventional local moment model assuming the presence of S=1/2 at each cluster, indicating that each Mo{sub 4} cluster behaves like a local spin with rigid magnitude. This behaviour is in contrast to the in-cluster relaxation, which reflects the spin-density fluctuations inside the cluster as a small unit of metal.

The effect of a neutrino magnetic moment on nuclear excitation processes

International Nuclear Information System (INIS)

Dodd, A.C.; Papageorgiu, E.; Ranfone, S.

1991-01-01

We discuss the sensitivity of magnetic transitions in nuclei like 12 C, to a small neutrino magnetic moment, and its implications for current and future experiments. We also point out that coherent neutrino-nuclear elastic scattering in low-temperature detectors, might improve the present laboratory bounds on the neutrino magnetic moment by an order of magnitude. (orig.)

Implications of the strange spin of the nucleon for the neutron electric dipole moment in supersymmetric theories

CERN Document Server

Ellis, Jonathan Richard; Ellis, John; Flores, Ricardo A

1996-01-01

Supersymmetric model contributions to the neutron electric dipole moment arise via quark electric dipole moment operators, whose matrix elements are usually calculated using the Naive Quark Model (NQM). However, experiments indicate that the NQM does not describe well the quark contributions \\Delta q to the nucleon spin, and so may provide misleading estimates of electric dipole operator matrix elements. Taking the \\Delta q from experiment, we indeed find consistently smaller estimates of the neutron electric dipole moment for given values of the supersymmetric model parameters. This weakens previous constraints on CP violation in supersymmetric models, which we exemplify analytically in the case where the lightest supersymmetric particle (LSP) is a U(1) gaugino \\tilde{B}, and display numerically for other LSP candidates.

Fingerprints of single nuclear spin energy levels using STM - ENDOR.

Science.gov (United States)

Manassen, Yishay; Averbukh, Michael; Jbara, Moamen; Siebenhofer, Bernhard; Shnirman, Alexander; Horovitz, Baruch

2018-04-01

We performed STM-ENDOR experiments where the intensity of one of the hyperfine components detected in ESR-STM is recorded while an rf power is irradiated into the tunneling junction and its frequency is swept. When the latter frequency is near a nuclear transition a dip in ESR-STM signal is observed. This experiment was performed in three different systems: near surface SiC vacancies where the electron spin is coupled to a next nearest neighbor 29 Si nucleus; Cu deposited on Si(111)7x7 surface, where the unpaired electron of the Cu atom is coupled to the Cu nucleus ( 63 Cu, 65 Cu) and on Tempo molecules adsorbed on Au(111), where the unpaired electron is coupled to a Nitrogen nucleus ( 14 N). While some of the hyperfine values are unresolved in the ESR-STM data due to linewidth we find that they are accurately determined in the STM-ENDOR data including those from remote nuclei, which are not detected in the ESR-STM spectrum. Furthermore, STM-ENDOR can measure single nuclear Zeeman frequencies, distinguish between isotopes through their different nuclear magnetic moments and detect quadrupole spectra. We also develop and solve a Bloch type equation for the coupled electron-nuclear system that facilitates interpretation of the data. The improved spectral resolution of STM - ENDOR opens many possibilities for nanometric scale chemical analysis. Copyright © 2018 Elsevier Inc. All rights reserved.

Spin, quadrupole moment, and deformation of the magnetic-rotational band head in (193)Pb

CERN Document Server

Balabanski, D L; Iordachescu, A; Bazzacco, D; Brandolini, F; Bucurescu, D; Chmel, S; Danchev, M; De Poli, M; Georgiev, G; Haas, H; Hubel, H; Marginean, N; Menegazzo, R; Neyens, G; Pavan, P; Rossi Alvarez, C; Ur, C A; Vyvey, K; Frauendorf, S

2011-01-01

The spectroscopic quadrupole moment of the T(1/2) = 9.4(5) ns isomer in (193)Pb at an excitation energy E(ex) = (2585 + x) keV is measured by the time-differential perturbed angular distribution method as vertical bar Q(s)vertical bar = 2.6(3) e b. Spin and parity I(pi) = 27/2(-) are assigned to it based on angular distribution measurements. This state is the band head of a magnetic-rotational band, described by the coupling of a neutron hole in the 1i(13/2) subshell with the (3s(1/2)(-2)1h(9/2)1i(13/2))(11-) proton excitation. The pairing-plus-quadrupole tilted-axis cranking calculations reproduce the measured quadrupole moment with a moderate oblate deformation epsilon(2) = -0.11, similar to that of the 11(-)proton intruder states, which occur in the even-even Pb nuclei in the region. This is the first direct measurement of a quadrupole moment and thus of the deformation of a magnetic-rotational band head.

Optical pumping of electron and nuclear spin in a negatively-charged quantum dot

Science.gov (United States)

Bracker, Allan; Gershoni, David; Korenev, Vladimir

2005-03-01

We report optical pumping of electron and nuclear spins in an individual negatively-charged quantum dot. With a bias-controlled heterostructure, we inject one electron into the quantum dot. Intense laser excitation produces negative photoluminescence polarization, which is easily erased by the Hanle effect, demonstrating optical pumping of a long-lived resident electron. The electron spin lifetime is consistent with the influence of nuclear spin fluctuations. Measuring the Overhauser effect in high magnetic fields, we observe a high degree of nuclear spin polarization, which is closely correlated to electron spin pumping.

Nuclear spin-lattice relaxation in n -type insulating and metallic GaAs single crystals

Science.gov (United States)

Lu, J.; Hoch, M. J. R.; Kuhns, P. L.; Moulton, W. G.; Gan, Z.; Reyes, A. P.

2006-09-01

The coupling of electron and nuclear spins in n-GaAs changes significantly as the donor concentration n increases through the insulator-metal critical concentration nC˜1.2×1016cm-3 . The present measurements of the Ga71 relaxation rates W made as a function of magnetic field (1-13T) and temperature (1.5-300K) for semi-insulating GaAs and for three doped n-GaAs samples with donor concentrations n=5.9×1015 , 7×1016 , and 2×1018cm-3 , show marked changes in the relaxation behavior with n . Korringa-like relaxation is found in both metallic samples for T30K phonon-induced nuclear quadrupolar relaxation is dominant. The relaxation rate measurements permit determination of the electron probability density at Ga71 sites. A small Knight shift of -3.3ppm was measured on the most metallic (2×1018cm-3) sample using magic-angle spinning at room temperature. For the n=5.9×1015cm-3 sample, a nuclear relaxation model involving the Fermi contact hyperfine interaction, rapid spin diffusion, and exchange coupled local moments is proposed. While the relaxation rate behavior with temperature for the weakly metallic sample, n=7×1016cm-3 , is similar to that found for the just-insulating sample, the magnetic field dependence is quite different. For the 5.9×1015cm-3 sample, increasing the magnetic field leads to a decrease in the relaxation rate, while for the 7×1016cm-3 sample this results in an increase in the relaxation rate ascribed to an increase in the density of states at the Fermi level as the Landau level degeneracy is increased.

Tensor quasiparticle interaction and spin-isospin sound in nuclear matter

International Nuclear Information System (INIS)

Haensel, P.

1979-01-01

The effect of the tensor components of the quasiparticle interaction in nuclear matter on the spin-isospin sound type excitations is studied. Numerical results are obtained using a simplified model of the quasiparticle interaction in nuclear matter. The quasiparticle distribution matrix corresponding to the spin-isospin sound is found to be qualitatively different from that obtained for purely central quasiparticle interaction. The macroscopic effects, however, are restricted to a small change in the phase velocity of the spin-isospin sound. (Auth.)

Isomer shift and magnetic moment of the long-lived 1/2$^{+}$ isomer in $^{79}_{30}$Zn$_{49}$: signature of shape coexistence near $^{78}$Ni

CERN Document Server

Yang, X.F.; Xie, L.; Babcock, C.; Billowes, J.; Bissell, M.L.; Blaum, K.; Cheal, B.; Flanagan, K.T.; Garcia Ruiz, R. F.; Gins, W.; Gorges, C.; Grob, L.K.; Heylen, H.; Kaufmann, S.; Kowalska, M.; Kraemer, J.; Malbrunot-Ettenauer, S.; Neugart, R.; Neyens, G.; Nörtershäuser, W.; Papuga, J.; Sánchez, R.; Yordanov, D.T.

2016-01-01

Collinear laser spectroscopy has been performed on the $^{79}_{30}$Zn$_{49}$ isotope at ISOLDE-CERN. The existence of a long-lived isomer with a few hundred milliseconds half-life was confirmed, and the nuclear spins and moments of the ground and isomeric states in $^{79}$Zn as well as the isomer shift were measured. From the observed hyperfine structures, spins $I = 9/2$ and $I = 1/2$ are firmly assigned to the ground and isomeric states. The magnetic moment $\\mu$ ($^{79}$Zn) = $-$1.1866(10) $\\mu_{\\rm{N}}$, confirms the spin-parity $9/2^{+}$ with a $\

Search for a permanent Xe-electric dipole moment

Energy Technology Data Exchange (ETDEWEB)

Zimmer, Stefan [Institut fuer Physik, Universitaet Mainz (Germany); Collaboration: MIXed-Collaboration

2016-07-01

A permanent electric dipole moment (EDM) of the isotope {sup 129}Xe would imply a breakdown of both parity P and time-reversal symmetry T and, through the CPT theorem, a breakdown in CP, the combined symmetries of charge conjugation C and parity P. Our goal is to improve the present experimental limit (d{sub Xe}<3.10{sup -27} ecm) by about three orders of magnitude. The most precise EDM limit on diamagnetic atoms was measured on {sup 199}Hg (d{sub Hg}<3.1.10{sup -29} ecm). To get more stringent limits, we perform a {sup 3}He/{sup 129}Xe clock comparison experiment with the detection of free spin precession of gaseous, nuclear polarized {sup 3}He or {sup 129}Xe samples with a SQUID as magnetic flux detector. The precession of co-located {sup 3}He/{sup 129}Xe nuclear spins are used as an ultra-sensitive probe for non-magnetic spin interactions of type δν∝ d{sub Xe}.E. With our experimental setup at the research center Juelich we are able to observe spin coherence times T{sub 2}{sup *} of several hours for both species. We report on first experimental results achieved within the MIXed-collaboration.

Long lived quantum memory with nuclear atomic spins

International Nuclear Information System (INIS)

Sinatra, A.; Reinaudi, G.; Dantan, A.; Giacobino, E.; Pinard, M.

2005-01-01

We propose store non-classical states of light into the macroscopic collective nuclear spin (10 18 atoms) of a 3 He vapor, using metastability exchange collisions. We show that these collisions currently used to transfer orientation from the metastable state 2 3 S 1 to the ground state state of 3 He, may conserve quantum correlations and give a possible experimental scheme to perfectly map a squeezed vacuum field state onto a nuclear spin state, which should allow for extremely long storage times (hours). In addition to the apparent interest for quantum information, the scheme offers the intriguing possibility to create a long-lived non classical state for spins. During a metastability exchange collision an atom in the ground state state and an atom in the metastable triplet state 2 3 S exchange their electronic spin variables. The ground state atom is then brought into the metastable state and vice-versa. A laser transition is accessible from the metastable state so that the metastable atoms are coupled with light. This, together with metastability exchange collisions, provides an effective coupling between ground state atoms and light. In our scheme, a coherent field and a squeezed vacuum field excite a Raman transition between Zeeman sublevels of the metastable state, after the system is prepared in the fully polarized state by preliminary optical pumping. According to the intensity of the coherent field, which acts as a control parameter, the squeezing of the field can be selectively transferred either to metastable or to ground state atoms. Once it is encoded in the purely nuclear spin of the ground state of 3 He, which is 20 eV apart from the nearest excited state and interacts very little with the environment, the quantum state can survive for times as long as several hours. By lighting up only the coherent field in the same configuration as for the 'writing' phase, the nuclear spin memory can be 'read' after a long delay, the squeezing being transferred

What can nuclear physics learn from nuclear moments

International Nuclear Information System (INIS)

Faessler, A.

1981-01-01

The information which can be obtained from static electric quadrupole and magnetic moments is discussed for some specific examples. A new highly controversial measurement of the g-factor of the 4 + state in 20 Ne is used to show the importance of magnetic moments on the understanding of nuclear structure. If the g-factor of the 4 + state in 20 Ne would indeed be zero which is very unlikely it would change our whole understanding of the sd-shell nuclei. In the second chapter we discuss a possible test of the nature of the anomaly of the moment of inertia in the rare earth nuclei. If it is an alignment of two i(13/2) neutrons along the total angular momentum the g-factor should drop to a very small value for angular momenta near backbending at the beginning of the rare earth region. In section 3 we discuss the change of the sign of the spectroscopic quadrupole moments for the 13/ 2 + isomeric state in the Hg isotopes as an example for a change from strong coupling to decoupling if one fills up the i(13/2) neutron shell. In section 4 we discuss the nature of the 8 + , 10 + and 12 + states in the even mass Hg and Pt isotopes which show an irregular energy spacing. Detailed theoretical calculations indicate that in the Hg isotopes up to mass number A = 196 the 8 + and 10 + states are formed by the partial and full alignment of two h(11/2) proton hole states, while in 198,200Hg the 8 + , 10 + and 12 + states are formed by partial and full alignment of two i(13/2) neutron holes. A recent argument using the energy position of the two quasi particle states claims the those states should be in all Hg isotopes i(13/2) quasi particle states. A measurement of the g-factors of those states could clear up their nature. (orig.)

Schemes of detecting nuclear spin correlations by dynamical decoupling based quantum sensing

Science.gov (United States)

Ma, Wen-Long Ma; Liu, Ren-Bao

Single-molecule sensitivity of nuclear magnetic resonance (NMR) and angstrom resolution of magnetic resonance imaging (MRI) are the highest challenges in magnetic microscopy. Recent development in dynamical decoupling (DD) enhanced diamond quantum sensing has enabled NMR of single nuclear spins and nanoscale NMR. Similar to conventional NMR and MRI, current DD-based quantum sensing utilizes the frequency fingerprints of target nuclear spins. Such schemes, however, cannot resolve different nuclear spins that have the same noise frequency or differentiate different types of correlations in nuclear spin clusters. Here we show that the first limitation can be overcome by using wavefunction fingerprints of target nuclear spins, which is much more sensitive than the ''frequency fingerprints'' to weak hyperfine interaction between the targets and a sensor, while the second one can be overcome by a new design of two-dimensional DD sequences composed of two sets of periodic DD sequences with different periods, which can be independently set to match two different transition frequencies. Our schemes not only offer an approach to breaking the resolution limit set by ''frequency gradients'' in conventional MRI, but also provide a standard approach to correlation spectroscopy for single-molecule NMR.

Manipulating spin in organic spintronics : probing the interplay between the electronic and nuclear spins in organic semiconductors

NARCIS (Netherlands)

Bobbert, P.A.

2014-01-01

The growing interest in spin manipulation in the field of spin electronics, or "spintronics," is due to the wealth of exciting possibilities that it offers in areas of magnetic sensing, new types of information storage, low-power electronics, and quantum information processing. Nuclear spin

Two methods for nuclear spin determination in collinear laser spectroscopy: classical r.f. magnetic resonance and observation of the Larmor precession

International Nuclear Information System (INIS)

Bendali, N.; Duong, H.T.; Saint-Jalm, J.M.; Vialle, J.L.

1984-01-01

Measurement of nuclear spin in the collinear laser spectroscopy method has been investigated using a fast sodium atomic beam excited collinearly by a C.W. single mode dye laser beam. The atomic magnetic moments are first aligned by optical pumping process, then they interact with a static magnetic field H 0 . The magnetic alignment of the atomic system just at the exit of the magnetic field is monitored by the laser induced fluorescence. Upon varying the amplitude of H 0 , the fluorescence signal presents a fringed structure. This structure is due to the Larmor precession of the aligned magnetic moments around H 0 , and therefore it is a signature of the spin involved. The modulation patterns corresponding to different relative orientations of H 0 and light polarization direction, are fitted by an analytical formula. In a second step, a classical magnetic resonance experiment with a static magnetic field and a radiofrequency field has been performed. The monocinetic character of our fast atomic beam allowed us to observe, even at high r.f. power, resonances line shapes in agreement with the Majorana formula

Moments Method for Shell-Model Level Density

International Nuclear Information System (INIS)

Zelevinsky, V; Horoi, M; Sen'kov, R A

2016-01-01

The modern form of the Moments Method applied to the calculation of the nuclear shell-model level density is explained and examples of the method at work are given. The calculated level density practically exactly coincides with the result of full diagonalization when the latter is feasible. The method provides the pure level density for given spin and parity with spurious center-of-mass excitations subtracted. The presence and interplay of all correlations leads to the results different from those obtained by the mean-field combinatorics. (paper)

Symmetry rules for the indirect nuclear spin-spin coupling tensor revisited

Science.gov (United States)

Buckingham, A. D.; Pyykkö, P.; Robert, J. B.; Wiesenfeld, L.

The symmetry rules of Buckingham and Love (1970), relating the number of independent components of the indirect spin-spin coupling tensor J to the symmetry of the nuclear sites, are shown to require modification if the two nuclei are exchanged by a symmetry operation. In that case, the anti-symmetric part of J does not transform as a second-rank polar tensor under symmetry operations that interchange the coupled nuclei and may be called an anti-tensor. New rules are derived and illustrated by simple molecular models.

Fullerene/layered antiferromagnetic reconstructed spinterface: Subsurface layer dominates molecular orbitals' spin-split and large induced magnetic moment

Science.gov (United States)

Shao, Yangfan; Pang, Rui; Pan, Hui; Shi, Xingqiang

2018-03-01

The interfaces between organic molecules and magnetic metals have gained increasing interest for both fundamental reasons and applications. Among them, the C60/layered antiferromagnetic (AFM) interfaces have been studied only for C60 bonded to the outermost ferromagnetic layer [S. L. Kawahara et al., Nano Lett. 12, 4558 (2012) and D. Li et al., Phys. Rev. B 93, 085425 (2016)]. Here, via density functional theory calculations combined with evidence from the literature, we demonstrate that C60 adsorption can reconstruct the layered-AFM Cr(001) surface at elevated annealing temperatures so that C60 bonds to both the outermost and the subsurface Cr layers in opposite spin directions. Surface reconstruction drastically changes the adsorbed molecule spintronic properties: (1) the spin-split p-d hybridization involves multi-orbitals of C60 and top two layers of Cr with opposite spin-polarization, (2) the subsurface Cr atom dominates the C60 electronic properties, and (3) the reconstruction induces a large magnetic moment of 0.58 μB in C60 as a synergistic effect of the top two Cr layers. The induced magnetic moment in C60 can be explained by the magnetic direct-exchange mechanism, which can be generalized to other C60/magnetic metal systems. Understanding these complex hybridization behaviors is a crucial step for molecular spintronic applications.

On the spin saturation and thermal properties of nuclear matter

International Nuclear Information System (INIS)

Hassan, M.Y.M.; Ramadan, S.

1983-12-01

The binding energy and the incompressibility of nuclear matter with degree of spin saturation D is calculated using the Skyrme interaction and two forms of a velocity dependent effective potential. The effect of the degree of spin saturation D on the thermal properties of nuclear matter is also discussed. It is found that generally the pressure decreases with increasing D. (author)

Isoscalar spin-spin interaction within the quasiparticle-phonon nuclear model

International Nuclear Information System (INIS)

Dao Tien Khoa; Ponomarev, V.Yu.; Vdovin, A.I.

1986-01-01

The isoscalar spin-spin interaction constant in the quasiparticle-phonon nuclear model (QPM) has been determined from the available experimental data on the isoscalar 1 + state (E x =5.846 MeV) in 208 Pb. The isoscalar spin-spin interaction turns out to be weaker than the isovector one by an order of magnitude. The cross sections of (e, e') and (p, p') reactions with the excitation of this 1 + -state have been calculated. The QPM gives a good description of the behaviour of (e, e')-cross section at q eff -1 and reproduces absolute value of this cross section with the effective g s -factors weaker than the g s -factors for free nucleon by 20%. The description of the (p, p')-angular distribution of 201 MeV photon inelastic scattering is poorer. The absolute value of the calculated (p, p') cross section overestimates the experimental data by a factor of about 1.4. This is consistent with the quenching factor for (e, e') cross section. The interaction with two-phonon configurations influences very weakly the isoscalar 1 + -level

Recursive polarization of nuclear spins in diamond at arbitrary magnetic fields

International Nuclear Information System (INIS)

Pagliero, Daniela; Laraoui, Abdelghani; Henshaw, Jacob D.; Meriles, Carlos A.

2014-01-01

We introduce an alternate route to dynamically polarize the nuclear spin host of nitrogen-vacancy (NV) centers in diamond. Our approach articulates optical, microwave, and radio-frequency pulses to recursively transfer spin polarization from the NV electronic spin. Using two complementary variants of the same underlying principle, we demonstrate nitrogen nuclear spin initialization approaching 80% at room temperature both in ensemble and single NV centers. Unlike existing schemes, our approach does not rely on level anti-crossings and is thus applicable at arbitrary magnetic fields. This versatility should prove useful in applications ranging from nanoscale metrology to sensitivity-enhanced NMR

Relativistic dynamics of point magnetic moment

Science.gov (United States)

Rafelski, Johann; Formanek, Martin; Steinmetz, Andrew

2018-01-01

The covariant motion of a classical point particle with magnetic moment in the presence of (external) electromagnetic fields is revisited. We are interested in understanding extensions to the Lorentz force involving point particle magnetic moment (Stern-Gerlach force) and how the spin precession dynamics is modified for consistency. We introduce spin as a classical particle property inherent to Poincaré symmetry of space-time. We propose a covariant formulation of the magnetic force based on a `magnetic' 4-potential and show how the point particle magnetic moment relates to the Amperian (current loop) and Gilbertian (magnetic monopole) descriptions. We show that covariant spin precession lacks a unique form and discuss the connection to g-2 anomaly. We consider the variational action principle and find that a consistent extension of the Lorentz force to include magnetic spin force is not straightforward. We look at non-covariant particle dynamics, and present a short introduction to the dynamics of (neutral) particles hit by a laser pulse of arbitrary shape.

Low-spin identical bands in rare earth nuclei

International Nuclear Information System (INIS)

Baktash, C.; Winchell, D.F.; Garrett, J.D.; Smith, A.

1992-01-01

A comprehensive study of odd-A rotational bands in normally deformed rare earth nuclei indicates that a large number of seniority-one configurations (21% for odd-Z nuclei) at low spin have moments of inertia nearly identical to that of the seniority-zero configuration of the neighboring even-even nucleus with one less nucleon. It is difficult to reconcile these results with conventional models of nuclear pair correlation, which predict variations of about 15% in the moments of inertia of configurations differing by one unit in seniority

Calculation of nuclear moment of inertia with proper treatment of pairing interaction

International Nuclear Information System (INIS)

Tazaki, S.; Ando, Y.; Hasegawa, M.

1997-01-01

An attempt to calculate nuclear moments of inertia treating the pairing interaction exactly is reported. As usual, hamiltonian is composed of the Nilsson's singleparticle energies and the pairing interaction, but the eigenstates and the eigenvalues are calculated exactly in a realistic, sufficiently large model space. The method of calculating the moment of inertia is presented. (author)

Nuclear energy at a moment of truth. Six reasons behind the case for nuclear power

International Nuclear Information System (INIS)

Ritch, J. III

2002-01-01

Through the years, the simple word 'nuclear' has become the focal point for a seemingly endless controversy, filled with passions and ideologies that sprang originally from a rational fear of nuclear war - but grew into an emotional, and now somewhat institutionalised, standoff that plagues public discourse as to how the world's nations can best meet their energy needs in the 21st century. Along the way, the very idea of nuclear energy became a political and psychological surrogate. Scepticism about government, distrust of large corporations, worry over toxic industrial effluents, a subconscious fear of cataclysm - all these real feelings and fears are crystallized, for many people, in a vague concept called 'the nuclear industry'. The subject of this presentation is that this is an idea whose time has come: that nuclear energy, a half century after its inception, has reached a moment of truth, in no less than six important respects: first, the technology has come of age; second, on a national level, key issues affecting nuclear energy will soon demand decision; third, fossil supplies may simply be inadequate to meet world energy needs; fourth, the valuable uses of nuclear power will soon multiply; fifth, and of profound importance, a massive shift toward nuclear power is now environmentally indispensable; sixth, this moment of truth for nuclear power requires a telling of the truth. Given the urgent need for public awareness and political decision, those able to do so must now make the case for nuclear energy - forcefully, without apology or equivocation, and with persuasive effect. A great deal depends on developing the wisdom and will to exploit nuclear technology to full benefit

Anomalous longitudinal relaxation of nuclear spins in CaF{sub 2}

Energy Technology Data Exchange (ETDEWEB)

Kropf, Chahan M. [Institute of Physics, University of Freiburg, Hermann-Herder-Str. 3, D-79104, Freiburg (Germany); Kohlrautz, Jonas; Haase, Juergen [University of Leipzig, Faculty of Physics and Earth Sciences, Linnestr. 5, 04103, Leipzig (Germany); Fine, Boris V. [Skolkovo Institute of Science and Technology, 100 Novaya Str., Skolkovo, Moscow Region, 143025 (Russian Federation); Institute for Theoretical Physics, University of Heidelberg, Philosophenweg 12, 69120, Heidelberg (Germany)

2017-06-15

We consider the effect of non-secular resonances for interacting nuclear spins in solids which were predicted theoretically to exist in the presence of strong static and strong radio-frequency magnetic fields. These resonances imply corrections to the standard secular approximation for the nuclear spin-spin interaction in solids, which, in turn, should lead to an anomalous longitudinal relaxation in nuclear magnetic resonance experiments. In this article, we investigate the feasibility of the experimental observation of this anomalous longitudinal relaxation in calcium fluoride (CaF{sub 2}) and conclude that such an observation is realistic. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Noise-Resilient Quantum Computing with a Nitrogen-Vacancy Center and Nuclear Spins.

Science.gov (United States)

Casanova, J; Wang, Z-Y; Plenio, M B

2016-09-23

Selective control of qubits in a quantum register for the purposes of quantum information processing represents a critical challenge for dense spin ensembles in solid-state systems. Here we present a protocol that achieves a complete set of selective electron-nuclear gates and single nuclear rotations in such an ensemble in diamond facilitated by a nearby nitrogen-vacancy (NV) center. The protocol suppresses internuclear interactions as well as unwanted coupling between the NV center and other spins of the ensemble to achieve quantum gate fidelities well exceeding 99%. Notably, our method can be applied to weakly coupled, distant spins representing a scalable procedure that exploits the exceptional properties of nuclear spins in diamond as robust quantum memories.

Optical switching of nuclear spin-spin couplings in semiconductors.

Science.gov (United States)

Goto, Atsushi; Ohki, Shinobu; Hashi, Kenjiro; Shimizu, Tadashi

2011-07-05

Two-qubit operation is an essential part of quantum computation. However, solid-state nuclear magnetic resonance quantum computing has not been able to fully implement this functionality, because it requires a switchable inter-qubit coupling that controls the time evolutions of entanglements. Nuclear dipolar coupling is beneficial in that it is present whenever nuclear-spin qubits are close to each other, while it complicates two-qubit operation because the qubits must remain decoupled to prevent unwanted couplings. Here we introduce optically controllable internuclear coupling in semiconductors. The coupling strength can be adjusted externally through light power and even allows on/off switching. This feature provides a simple way of switching inter-qubit couplings in semiconductor-based quantum computers. In addition, its long reach compared with nuclear dipolar couplings allows a variety of options for arranging qubits, as they need not be next to each other to secure couplings.

Nuclear structure and magnetic moment of the unstable 12B-12N mirror pair

International Nuclear Information System (INIS)

Zheng Yongnan; Zhou Dongmei; Yuan Daqing; Zuo Yi; Fan Ping; Xu Yongjun; Zhu Jiazheng; Wang Zhiqiang; Luo Hailong; Zhang Xizhen; Zhu Shengyun; Mihara, M.; Matsuta, K.; Fukuda, M.; Minamisono, T.; Suzuki, T.

2010-01-01

Magnetic moments of the A=12 unstable mirror pair nuclides 12 B and 12 N have been measured by the β-NMR technique. The experimentally measured magnetic moments are μ( 12 B)=1.00(17)μ N and μ( 12 N)=0.4571(1)μ N . The improved shell model using an SFO Hamiltonian with enhanced spin-isospin monopole proton-neutron interaction and modified single-particle energies is employed to calculate the magnetic moments of 12 B and 12 N. The calculation yields μ( 12 B)=0.929μ N and μ( 12 N)=0.452μ N and has produced a new magic number 6 for the short-lived unstable mirror pair nuclides 12 B and 12 N. (authors)

The nuclear spin-orbit coupling

International Nuclear Information System (INIS)

Bell, J.S.; Skyrme, T.H.R.

1994-01-01

Analysis of the nucleon-nucleon scattering around 100 MeV has determined the spin-orbit coupling part of the two-body scattering matrix at that energy, and a reasonable extrapolation to lower energies is possible. This scattering amplitude has been used, in the spirit of Brueckner's nuclear model, to estimate the resultant single-body spin-orbit coupling for a single nucleon interacting with a large nucleus. This resultant potential has a radial dependence approximately proportional to r -1 d ρ /dr, and with a magnitude in good agreement with that required to explain the doublet splittings in nuclei and the polarization of nucleons scattered elastically off nuclei. (author). 14 refs, 2 figs

Nuclear quadrupole moment of the 99Tc ground state

International Nuclear Information System (INIS)

Errico, Leonardo; Darriba, German; Renteria, Mario; Tang Zhengning; Emmerich, Heike; Cottenier, Stefaan

2008-01-01

By combining first-principles calculations and existing nuclear magnetic resonance (NMR) experiments, we determine the quadrupole moment of the 9/2 + ground state of 99 Tc to be (-)0.14(3)b. This confirms the value of -0.129(20)b, which is currently believed to be the most reliable experimental determination, and disagrees with two earlier experimental values. We supply ab initio calculated electric-field gradients for Tc in YTc 2 and ZrTc 2 . If this calculated information would be combined with yet to be performed Tc-NMR experiments in these compounds, the error bar on the 99 Tc ground state quadrupole moment could be further reduced

Response function of spin-isospin nuclear excitations

International Nuclear Information System (INIS)

Salvetti, A.R.

1986-01-01

The selected aspects of spin-isospir nuclear excitations are studied. The spreading width of M/ states in even Ca isotopes for the purpose of trying to understand the missing strenght specially in 44 Ca, was estimated. The doorway calculation, was used, considering the level of complexity next to the independent particle M/ state. Using a nuclear matter context, the system response function to a spin-isospin probe and verify how the response function behaves for free fermions and in the ring approximation was studied. Higher correlations to polarization propagation such as the induced interaction and self-energy corrections was introduced. The dopping of colletive effects by such collisions terms was verified. It was investigate how to estimate the short range term of the effective interaction in the spin-isospin channel and the possibility of detecting a difference between these short range terms in the longitudinal and the transverse channel, for understanding the absence of pior condensation precursor states and negative results in a recent attempt to detect differences between longitudinal and transverse response functions one naively expects theoretically. (author) [pt

Nuclear spin relaxation by translational diffusion in solids

International Nuclear Information System (INIS)

Barton, W.A.; Sholl, C.A.

1978-01-01

The theory of nuclear spin relaxation by translational diffusion in solids developed in previous papers is applied to two-spin systems and third-nearest-neighbour jump models in FCC crystals. The two-spin systems describe the dipole-dipole interactions between stationary host spins and spins migrating amongst either the tetrahedral or the octahedral interstitial sites. The tetrahedral sites in a FCC crystal form a SC lattice and two models, the symmetric and asymmetric jump models, are considered for third-nearest-neighbour jumps on this lattice. Numerical results for the correlation function relevant for single crystals and polycrystals are presented over the entire temperature range. It is found that the simpler, but unphysical, symmetric jump model is a good approximation to the more complicated asymmetric jump model. (author)

Room-temperature coupling between electrical current and nuclear spins in OLEDs

Science.gov (United States)

Malissa, H.; Kavand, M.; Waters, D. P.; van Schooten, K. J.; Burn, P. L.; Vardeny, Z. V.; Saam, B.; Lupton, J. M.; Boehme, C.

2014-09-01

The effects of external magnetic fields on the electrical conductivity of organic semiconductors have been attributed to hyperfine coupling of the spins of the charge carriers and hydrogen nuclei. We studied this coupling directly by implementation of pulsed electrically detected nuclear magnetic resonance spectroscopy in organic light-emitting diodes (OLEDs). The data revealed a fingerprint of the isotope (protium or deuterium) involved in the coherent spin precession observed in spin-echo envelope modulation. Furthermore, resonant control of the electric current by nuclear spin orientation was achieved with radiofrequency pulses in a double-resonance scheme, implying current control on energy scales one-millionth the magnitude of the thermal energy.

Spin transfer in reactions between heavy ions

International Nuclear Information System (INIS)

Dong Pil Min.

1980-06-01

The model presented affords a better understanding of the manner in which the orbital angular moment can be converted into an intrinsic spin in the collision between two heavy ions. After referring to the vector fields and the collective energy of a spheroidal nucleus, the calculation of the exchange of nucleons is described and the dissipation function is constructed. The spin transfer and the reorientation of the spin during the reaction are then examined (effect of friction and vibration). The estimated calculations are compared with the results of the 63 Cu+ 197 Au and 86 Kr+ 209 Bi experiments. The sensitivity of the calculation to the parameters of the model is discussed (nuclear potential, vibrational inertial parameter) [fr

Nuclear reactivity indices in the context of spin polarized density functional theory

International Nuclear Information System (INIS)

Cardenas, Carlos; Lamsabhi, Al Mokhtar; Fuentealba, Patricio

2006-01-01

In this work, the nuclear reactivity indices of density functional theory have been generalized to the spin polarized case and their relationship to electron spin polarized indices has been established. In particular, the spin polarized version of the nuclear Fukui function has been proposed and a finite difference approximation has been used to evaluate it. Applications to a series of triatomic molecules demonstrate the ability of the new functions to predict the geometrical changes due to a change in the spin multiplicity. The main equations in the different ensembles have also been presented

Manifestations of classical physics in the quantum evolution of correlated spin states in pulsed NMR experiments.

Science.gov (United States)

Ligare, Martin

2016-05-01

Multiple-pulse NMR experiments are a powerful tool for the investigation of molecules with coupled nuclear spins. The product operator formalism provides a way to understand the quantum evolution of an ensemble of weakly coupled spins in such experiments using some of the more intuitive concepts of classical physics and semi-classical vector representations. In this paper I present a new way in which to interpret the quantum evolution of an ensemble of spins. I recast the quantum problem in terms of mixtures of pure states of two spins whose expectation values evolve identically to those of classical moments. Pictorial representations of these classically evolving states provide a way to calculate the time evolution of ensembles of weakly coupled spins without the full machinery of quantum mechanics, offering insight to anyone who understands precession of magnetic moments in magnetic fields.

Nuclear-spin-dependent parity-nonconserving effects in thallium, lead and bismuth atoms

International Nuclear Information System (INIS)

Khriplovich, I.B.

1994-01-01

Nuclear-spin-dependent P-odd optical activity in atomic Tl, Pb and Bi is calculated. Its magnitude is expressed analytically through the main contribution to the optical rotation, which is independent of nuclear spin. The accuracy of results is discussed. 31 refs., 2 tabs

Magnetic pseudo-fields in a rotating electron-nuclear spin system

Science.gov (United States)

Wood, A. A.; Lilette, E.; Fein, Y. Y.; Perunicic, V. S.; Hollenberg, L. C. L.; Scholten, R. E.; Martin, A. M.

2017-11-01

Analogous to the precession of a Foucault pendulum observed on the rotating Earth, a precessing spin observed in a rotating frame of reference appears frequency-shifted. This can be understood as arising from a magnetic pseudo-field in the rotating frame that nevertheless has physically significant consequences, such as the Barnett effect. To detect these pseudo-fields, a rotating-frame sensor is required. Here we use quantum sensors, nitrogen-vacancy (NV) centres, in a rapidly rotating diamond to detect pseudo-fields in the rotating frame. Whereas conventional magnetic fields induce precession at a rate proportional to the gyromagnetic ratio, rotation shifts the precession of all spins equally, and thus primarily affect 13C nuclear spins in the sample. We are thus able to explore these effects via quantum sensing in a rapidly rotating frame, and define a new approach to quantum control using rotationally induced nuclear spin-selective magnetic fields. This work provides an integral step towards realizing precision rotation sensing and quantum spin gyroscopes.

Advances and applications of dynamic-angle spinning nuclear magnetic resonance

International Nuclear Information System (INIS)

Baltisberger, J.H.

1993-06-01

This dissertation describes nuclear magnetic resonance experiments and theory which have been developed to study quadrupolar nuclei (those nuclei with spin greater than one-half) in the solid state. Primarily, the technique of dynamic-angle spinning (DAS) is extensively reviewed and expanded upon in this thesis. Specifically, the improvement in both the resolution (two-dimensional pure-absorptive phase methods and DAS angle choice) and sensitivity (pulse-sequence development), along with effective spinning speed enhancement (again through choice of DAS conditions or alternative multiple pulse schemes) of dynamic-angle spinning experiment was realized with both theory and experimental examples. The application of DAS to new types of nuclei (specifically the 87 Rb and 85 Rb nuclear spins) and materials (specifically amorphous solids) has also greatly expanded the possibilities of the use of DAS to study a larger range of materials. This dissertation is meant to demonstrate both recent advances and applications of the DAS technique, and by no means represents a comprehensive study of any particular chemical problem

Nuclear Magnetic Dipole and Electric Quadrupole Moments: Their Measurement and Tabulation as Accessible Data

Energy Technology Data Exchange (ETDEWEB)

Stone, N. J., E-mail: n.stone@physics.ox.ac.uk [Department of Physics and Astronomy, University of Tennessee, Knoxville Tennessee 37996 (United States)

2015-09-15

The most recent tabulations of nuclear magnetic dipole and electric quadrupole moments have been prepared and published by the Nuclear Data Section of the IAEA, Vienna [N. J. Stone, Report No. INDC(NDS)-0650 (2013); Report No. INDC(NDS)-0658 (2014)]. The first of these is a table of recommended quadrupole moments for all isotopes in which all experimental results are made consistent with a limited number of adopted standards for each element; the second is a combined listing of all measurements of both moments. Both tables cover all isotopes and energy levels. In this paper, the considerations relevant to the preparation of both tables are described, together with observations as to the importance and (where appropriate) application of necessary corrections to achieve the “best” values. Some discussion of experimental methods is included with emphasis on their precision. The aim of the published quadrupole moment table is to provide a standard reference in which the value given for each moment is the best available and for which full provenance is given. A table of recommended magnetic dipole moments is in preparation, with the same objective in view.

Nuclear spin bath effects in molecular nanomagnets: Direct quantum mechanical simulations

Science.gov (United States)

Sinitsyn, N. A.; Dobrovitski, V. V.

2004-11-01

We investigate the influence of nuclear spins on the electronic spin tunneling in magnetic molecules such as Fe8 , focusing on the role of the spin diffusion in the nuclear spin bath. We simulate the quantum spin dynamics by numerically solving the time-dependent Schrödinger equation for the compound system (the electronic spin plus the bath spins). Our results demonstrate that the effect of the spin bath cannot always be modeled as a randomly varying magnetic field acting on the electronic spin. We consider two dynamical regimes: the spin relaxation in a constant magnetic field, and the spin tunneling in the linearly varying magnetic field passing the avoided level crossing, so-called Landau-Zener-Stückelberg (LZS) transition. For the first regime, we confirmed that the hole in the magnetization distribution has the width of the hyperfine fields distribution. For the second regime, we found that the transition probability for moderately slow sweeps deviates from the standard LZS prediction, while for the fast sweeps the deviation is negligible.

Magnetic dipole moments of odd-odd lanthanides

International Nuclear Information System (INIS)

Sharma, S.D.; Gandhi, R.

1988-01-01

Magnetic dipole moments of odd-odd lanthanides. Collective model of odd-odd nuclei is applied to predict the magnetic dipole moments, (μ) of odd-odd lanthanides. A simplified version of expression for μ based on diagonalisation of Hamiltonian (subsequent use of eigenvectors to compute μ) is developed for cases of ground state as well as excited states using no configuration mixing and is applied to the cases of odd-odd lanthanides. The formulae applied to the eleven (11) cases of ground states show significant improvement over the results obtained using shell model. Configuration mixing and coriolis coupling is expected to cause further improvement in the results. On comparing the earlier work in this direction the present analysis has clarified that in the expression μ the projection factors have different signs for the case I=Ωp - Ωn and I=Ωn - Ωp, and sign of μ is negative in general in the second case while it is positive in all others of spin projection alignments. Although the general expression holds for excited states as well but in lanthanide region, the experimental reports of magnetic dipole moments of excite states (band heads of higher rational sequences) are not available except in case of five (5) neutron resonance states which cannot be handled on the basis of the present approach with no configuration mixing. Although in the present discussion, the model could not be applied to excited states but the systematics of change in its magnitude with increasing spin at higher rational states is very well understood. The particle part supressed under faster rotation of the nuclear core and thus finally at higher spin I, the value μ is given by μ=g c I (same as in case of even-even nuclei). These systematics are to be verified whenever enough data for higher excited states are available. (author). 11 refs

Nuclear spin polarization of targets

International Nuclear Information System (INIS)

Happer, W.

1990-01-01

Lasers can be used to produce milligrams to grams of noble gas nuclei with spin polarizations in excess of 50%. These quantities are sufficient to be very useful targets in nuclear physics experiments. Alkali-metal atoms are used to capture the angular momentum of circularly polarized laser photons, and the alkali-metal atoms transfer their angular momentum to noble gas atoms in binary or three-body collisions. Non-radiative collisions between the excited alkali atoms and molecular quenching gases are essential to avoid radiation trapping. The spin exchange can involve gas-phase van der Waals molecules, consisting of a noble gas atom and an alkali metal atom. Surface chemistry is also of great importance in determining the wall-induced relaxation rates of the noble gases

Relativistic dynamics of point magnetic moment

Energy Technology Data Exchange (ETDEWEB)

Rafelski, Johann; Formanek, Martin; Steinmetz, Andrew [The University of Arizona, Department of Physics, Tucson, AZ (United States)

2018-01-15

The covariant motion of a classical point particle with magnetic moment in the presence of (external) electromagnetic fields is revisited. We are interested in understanding extensions to the Lorentz force involving point particle magnetic moment (Stern-Gerlach force) and how the spin precession dynamics is modified for consistency. We introduce spin as a classical particle property inherent to Poincare symmetry of space-time. We propose a covariant formulation of the magnetic force based on a 'magnetic' 4-potential and show how the point particle magnetic moment relates to the Amperian (current loop) and Gilbertian (magnetic monopole) descriptions. We show that covariant spin precession lacks a unique form and discuss the connection to g - 2 anomaly. We consider the variational action principle and find that a consistent extension of the Lorentz force to include magnetic spin force is not straightforward. We look at non-covariant particle dynamics, and present a short introduction to the dynamics of (neutral) particles hit by a laser pulse of arbitrary shape. (orig.)

Unresolved gamma rays from high-spin states

International Nuclear Information System (INIS)

Stephens, F.S.

1985-08-01

The γ-rays which are emitted from the highest spin states in nuclei cannot be resolved using present techniques. Nevertheless, methods are being developed to study nuclear structures in this spin range. For example, coincidence data has been used in the study of superdeformations and moments of inertia. While the general properties of these correlation plots are in accord with present expectations, there are several puzzling features of the data which require more study. One unresolved aspect concerns γ-ray energy spreads in a given decay pathway. In addition, higher-order correlation methods are in various stages of inception. 15 refs., 16 figs

Magnetic moment of the fragmentation-aligned F61e (9/2+) isomer

International Nuclear Information System (INIS)

Matea, I.; Georgiev, G.; Lewitowicz, M.; Santos, F. de Oliveira; Daugas, J.M.; Belier, G.; Goutte, H.; Meot, V.; Roig, O.; Hass, M.; Baby, L.T.; Goldring, G.; Neyens, G.; Borremans, D.; Himpe, P.; Astabatyan, R.; Lukyanov, S.; Penionzhkevich, Yu.E.; Balabanski, D.L.; Sawicka, M.

2004-01-01

We report on the g factor measurement of an isomer in the neutron-rich F 26 61 e (E * =861 keV and T 1/2 =239(5) ns). The isomer was produced and spin aligned via a projectile-fragmentation reaction at intermediate energy, the time dependent perturbed angular distribution method being used for the measurement of the g factor. For the first time, due to significant improvements of the experimental technique, an appreciable residual alignment of the nuclear spin ensemble has been observed, allowing a precise determination of its g factor, including the sign: g=-0.229(2). In this way we open the possibility to study moments of very neutron-rich short-lived isomers, not accessible via other production and spin-orientation methods

Order and chaos in the nonlinear response of driven nuclear spin systems

Energy Technology Data Exchange (ETDEWEB)

Brun, E; Derighetti, B; Holzner, R; Ravani, M [Zurich Univ. (Switzerland). Inst. fuer Physik

1984-01-01

The authors report on observations of ordered and chaotic behavior of a nonlinear system of strongly polarized nuclear spins inside the tuning coil of an NMR detector. The combined system: spins plus LC-circuit, may act as a nonlinear bistable absorber or a spin-flip laser, depending on the sign of the nuclear spin polarization. For the NMR laser experimental evidence is presented for limit-cycle behavior, sequences of bifurcations which lead to chaos, intermittency, multistability, and pronounced hysteresis effects. The experimental facts are compared with computer solutions of appropriate Bloch equations for the macroscopic order parameters.

Physics of high spin nuclear states

Energy Technology Data Exchange (ETDEWEB)

Wyss, R [Joint Inst. for Heavy Ion Research, Oak Ridge, TN (United States); [MSI, Frescativ, Stockholm (Sweden)

1992-08-01

High spin physics is a vast topic addressing the variety of nuclear excitation modes. In the present paper, some general aspects related to recent highlights of nuclear spectroscopy are discussed. The relation between signature splitting and shape changes in the unique parity orbitals is elucidated. The relevance of the Pseudo SU(3) symmetry in the understanding of rotational band structure is addressed. Specific features of rotational bands of intruder configurations are viewed as a probe of the neutron-proton interaction. (author). 36 refs., 5 figs.

Experimental status of the nuclear spin scissors mode

Science.gov (United States)

Balbutsev, E. B.; Molodtsova, I. V.; Schuck, P.

2018-04-01

With the Wigner function moments (WFM) method the scissors mode of the actinides and rare earth nuclei are investigated. The unexplained experimental fact that in 232Th a double hump structure is found finds a natural explanation within WFM. It is predicted that the lower peak corresponds to an isovector spin scissors mode whereas the higher-lying states corresponds to the conventional isovector orbital scissors mode. The experimental situation is scrutinized in this respect concerning practically all results of M 1 excitations.

Toroidal high-spin isomers in the nucleus 304120

Science.gov (United States)

Staszczak, A.; Wong, Cheuk-Yin; Kosior, A.

2017-05-01

Background: Strongly deformed oblate superheavy nuclei form an intriguing region where the toroidal nuclear structures may bifurcate from the oblate spheroidal shape. The bifurcation may be facilitated when the nucleus is endowed with a large angular moment about the symmetry axis with I =Iz . The toroidal high-K isomeric states at their local energy minima can be theoretically predicted using the cranked self-consistent Skyrme-Hartree-Fock method. Purpose: We use the cranked Skyrme-Hartree-Fock method to predict the properties of the toroidal high-spin isomers in the superheavy nucleus 120304184. Method: Our method consists of three steps: First, we use the deformation-constrained Skyrme-Hartree-Fock-Bogoliubov approach to search for the nuclear density distributions with toroidal shapes. Next, using these toroidal distributions as starting configurations, we apply an additional cranking constraint of a large angular momentum I =Iz about the symmetry z axis and search for the energy minima of the system as a function of the deformation. In the last step, if a local energy minimum with I =Iz is found, we perform at this point the cranked symmetry- and deformation-unconstrained Skyrme-Hartree-Fock calculations to locate a stable toroidal high-spin isomeric state in free convergence. Results: We have theoretically located two toroidal high-spin isomeric states of 120304184 with an angular momentum I =Iz=81 ℏ (proton 2p-2h, neutron 4p-4h excitation) and I =Iz=208 ℏ (proton 5p-5h, neutron 8p-8h) at the quadrupole moment deformations Q20=-297.7 b and Q20=-300.8 b with energies 79.2 and 101.6 MeV above the spherical ground state, respectively. The nuclear density distributions of the toroidal high-spin isomers 120304184(Iz=81 ℏ and 208 ℏ ) have the maximum density close to the nuclear matter density, 0.16 fm-3, and a torus major to minor radius aspect ratio R /d =3.25 . Conclusions: We demonstrate that aligned angular momenta of Iz=81 ℏ and 208 ℏ arising from

Spin dynamics of paramagnetic centers with anisotropic g tensor and spin of 1/2

Science.gov (United States)

Maryasov, Alexander G.; Bowman, Michael K.

2012-08-01

The influence of g tensor anisotropy on spin dynamics of paramagnetic centers having real or effective spin of 1/2 is studied. The g anisotropy affects both the excitation and the detection of EPR signals, producing noticeable differences between conventional continuous-wave (cw) EPR and pulsed EPR spectra. The magnitudes and directions of the spin and magnetic moment vectors are generally not proportional to each other, but are related to each other through the g tensor. The equilibrium magnetic moment direction is generally parallel to neither the magnetic field nor the spin quantization axis due to the g anisotropy. After excitation with short microwave pulses, the spin vector precesses around its quantization axis, in a plane that is generally not perpendicular to the applied magnetic field. Paradoxically, the magnetic moment vector precesses around its equilibrium direction in a plane exactly perpendicular to the external magnetic field. In the general case, the oscillating part of the magnetic moment is elliptically polarized and the direction of precession is determined by the sign of the g tensor determinant (g tensor signature). Conventional pulsed and cw EPR spectrometers do not allow determination of the g tensor signature or the ellipticity of the magnetic moment trajectory. It is generally impossible to set a uniform spin turning angle for simple pulses in an unoriented or 'powder' sample when g tensor anisotropy is significant.

Entanglement measures in embedding quantum simulators with nuclear spins

Science.gov (United States)

Xin, Tao; Pedernales, Julen S.; Solano, Enrique; Long, Gui-Lu

2018-02-01

We implement an embedding quantum simulator (EQS) in nuclear spin systems. The experiment consists of a simulator of up to three qubits, plus a single ancillary qubit, where we are able to efficiently measure the concurrence and the three-tangle of two-qubit and three-qubit systems as they undergo entangling dynamics. The EQS framework allows us to drastically reduce the number of measurements needed for this task, which otherwise would require full-state reconstruction of the qubit system. Our simulator is built of the nuclear spins of four 13C atoms in a molecule of trans-crotonic acid manipulated with NMR techniques.

Evolution of nuclear collectivity at high spins and temperatures

International Nuclear Information System (INIS)

Baktash, C.

1989-01-01

In the past few years, we have utilized the Spin Spectrometer and a variety of complementary probes (continuum γrays, proton-γ coincidence spectroscopy and γ decay of GDR) to study the nuclear response to the DIFFERENTIAL effects of increasing spin and temperature for constant values of excitation energy or spin, respectively. In this paper we shall describe two of the experiments that trace the properties of rapidly-rotating nuclei at small to moderate excitation energies. 22 refs., 7 figs

Advances and applications of dynamic-angle spinning nuclear magnetic resonance

Energy Technology Data Exchange (ETDEWEB)

Baltisberger, Jay Harvey [Univ. of California, Berkeley, CA (United States)

1993-06-01

This dissertation describes nuclear magnetic resonance experiments and theory which have been developed to study quadrupolar nuclei (those nuclei with spin greater than one-half) in the solid state. Primarily, the technique of dynamic-angle spinning (DAS) is extensively reviewed and expanded upon in this thesis. Specifically, the improvement in both the resolution (two-dimensional pure-absorptive phase methods and DAS angle choice) and sensitivity (pulse-sequence development), along with effective spinning speed enhancement (again through choice of DAS conditions or alternative multiple pulse schemes) of dynamic-angle spinning experiment was realized with both theory and experimental examples. The application of DAS to new types of nuclei (specifically the {sup 87}Rb and {sup 85}Rb nuclear spins) and materials (specifically amorphous solids) has also greatly expanded the possibilities of the use of DAS to study a larger range of materials. This dissertation is meant to demonstrate both recent advances and applications of the DAS technique, and by no means represents a comprehensive study of any particular chemical problem.

Environmental Effects on Quantum Reversal of Mesoscopic Spins

Science.gov (United States)

Giraud, R.; Chiorescu, I.; Wernsdorfer, W.; Barbara, B.; Jansen, A. G. M.; Caneschi, A.; Mueller, A.; Tkachuk, A. M.

2002-10-01

We describe what we learnt these last years on quantum reversal of large magnetic moments, using mainly conventional SQUID or micro-SQUID magnetometry. Beside the case of ferromagnetic nanoparticles with 103 - 105 atoms (e.g. Co, Ni, Fe, Ferrites), most fruitful systems appeared to be ensembles of magnetic molecules. These molecules, generally arranged in single crystals, carry relatively small magnetic moments (S = 10 in Mn12-ac and Fe8). They are sufficiently apart from each other not to be coupled by exchange interactions. The ground multiplet is split over an energy barrier of tens of kelvin (≈ 67 K for Mn12) by a strong local crystal field, leading to an Ising-type ground-state. Only weak inter-molecular dipolar interactions are present, as well as intra-molecular interactions, such as hyperfine interactions. Quantum properties of molecule spins are crucially dependent on their magnetic environment of electronic and nuclear spins (the spin bath). Energy fluctuations of the spin bath of about 0.1 K are important, especially at very low temperatures. In particular, they are much larger than the ground-state tunnel splitting of large-spin molecules in low applied fields, of about 10-8 K or even less (such a low value is due to the presence of large energy barriers). Theoretical predictions are experimentally checked for tunneling effects in the presence of non-equilibrated or equilibrated spin-energy distribution. It is also shown that the phonon-bath plays no role in low field, except when the temperature approaches the cross-over temperature to the thermal activation regime. In fact, spin-phonon transitions can play a role only if the tunnel splitting is not too small in comparison with kBT. This is the case both for large-spin molecules in a large magnetic field (e.g. Mn12-ac in a few tesla) and for low-spin molecules, as shown with the study of the molecule V15 (Hilbert space dimension as large as 215 and spin 1/2). We also give our latest results on the

Nuclear magnetic moment of 69As from on-line β-NMR on oriented nuclei

International Nuclear Information System (INIS)

Golovko, V.V.; Kraev, I.S.; Phalet, T.; Severijns, N.; Delaure, B.; Beck, M.; Kozlov, V.Yu.; Lindroth, A.; Coeck, S.; Zakoucky, D.; Venos, D.; Srnka, D.; Honusek, M.; Herzog, P.; Tramm, C.; Koester, U.

2005-01-01

A precise value for the magnetic moment of the 69 As 5/2 - ground state has been obtained from nuclear magnetic resonance on oriented nuclei (NMR/ON) using the NICOLE 3 He- 4 He dilution refrigerator setup at ISOLDE/CERN. The NMR/ON signal was observed by monitoring the anisotropy of the 69 As β particles. The center frequency ν[B ext =0.0994(10)T]=169.98(9) MHz corresponds to μ[ 69 As]=+1.6229(16)μ N . This result differs considerably from the πf 5/2 single-particle value obtained with g factors for a free proton but is in reasonable agreement with the value obtained with effective g factors and with values from a core polarization calculation and from calculations in the framework of the interacting boson-fermion model. Assuming a single exponential spin-lattice relaxation behavior a relaxation time T 1 ' =10(25) s was observed for 69 AsFe -bar at a temperature of about 20 mK in a magnetic field B=0.1 T

Floating Characteristics of Rudders and Elevators in Spinning Attitudes as Determined From Hinge-Moment-Coefficient Data With Application to Personal-Owner-Type Airplanes

National Research Council Canada - National Science Library

Bihrle, William

1950-01-01

A study was made of available rudder and elevator hinge-moment-coefficient-coefficient data in order to determine the floating characteristics of various types of rudders and elevators in spinning attitudes...

Absence of hyperfine effects in 13C-graphene spin-valve devices

NARCIS (Netherlands)

Wojtaszek, M.; Vera-Marun, I.J.; Whiteway, E.; Hilke, M.; Wees, B.J. van

2014-01-01

The carbon isotope 13C, in contrast to 12C, possesses a nuclear magnetic moment and can induce electron spin dephasing in graphene. This effect is usually neglected due to the low abundance of 13C in natural carbon allotropes (~1%). Chemical vapor deposition (CVD) allows for artificial synthesis of

Serber says: About nuclear physics

International Nuclear Information System (INIS)

Serber, R.

1986-01-01

This book is a distillation of a set of lecture notes used by the author at Columbia. Written with a pedagogical aim it emphasizes topics of current interest not only in nuclear physics but also in other branches of physics such as atomic physics and solid state physics. Contents: Some Arguments Concerning Nuclear Forces; The Neutron-Proton Force; Low Energy Neutron-Proton Scattering Experiments; Photo-Effect of the Deuteron; The Slowing Down and Diffusion of Neutrons; Nucleon Magnetic Moments and Quadrupole Moment of the Deuteron; Proton-Proton and Neutron-Neutron Interactions; Isotopic Spin Invariance; High Energy Reactions; Resonance Levels

Low-spin identical bands in odd-A nuclei

International Nuclear Information System (INIS)

Baktash, C.; Garrett, J.D.; Winchell, D.F.; Smith, A.

1992-01-01

A comprehensive study of odd-A rotational bands in normally-deformed rare-earth nuclei indicates that a large number of seniority-one configurations (30% for odd-Z nuclei) at low spin have moments of inertia nearly identical to that of the seniority-zero configuration of the neighboring even-even nucleus with one less nucleon. It is difficult to reconcile these results with conventional models, based on the traditional picture of nuclear pair correlation in vogue for more than three decades, which predict variations of about 15% in the moments of inertia of configurations differing by one unit in seniority

Production of spin-polarized unstable nuclei by using polarized electron capture process

International Nuclear Information System (INIS)

Shimizu, S.

1998-01-01

Measurements of emitted radiation from spin polarized nuclei are used to get information on electromagnetic moment of ground state unstable nuclei together with spin or parity state of excited states of their decayed (daughter) nuclei. These data are known to be useful for experimental investigation into the structure of unstable nuclei far from the stability line. The present study aims to establish a general method applicable to 11 Be and 16 N nuclei. To produce spin polarization, a new method in which the electron spin polarization of Rb is firstly produced by laser pumping, then the electron is transferred to the unstable nuclear beam (RNB) when they passes through the Rb vapor is proposed. Finally the polarized RNB will be implanted into superfluid helium to remain with a long spin-relaxation time. Future experimental set up for the above measurement adopted in the available radioactive nuclear beam facilities is briefly described. (Ohno, S.)

The Boulder measurement of parity violation and an anapole moment in cesium

International Nuclear Information System (INIS)

Cho, D.; Wood, C.S.; Bennett, S.C.; Roberts, J.L.; Masterson, B.P.; Tanner, C.E.; Wieman, C.E.

1999-01-01

The amplitude of the parity-nonconserving transition between the 6S and 7S states of cesium was precisely measured with the use of a spin-polarized atomic beam. This measurement gives Im(E1 pnc )/β = - 1.5935(56) milli-volts per centimeter and provides an improved test of the standard model at low energy, including a value for the S parameter of -1.3(3) exp (11) theory . The nuclear spin-dependent contributions was 0.077(11) milli-volts per centimeter, this contribution is a manifestation of parity violation in atomic nuclei and is a measurement of the long-sought anapole moment. (authors)

Ab initio determination of the nuclear quadrupole moments of 114In, 115In, and 117In

International Nuclear Information System (INIS)

Errico, Leonardo A.; Renteria, Mario

2006-01-01

We present here ab initio determinations of the nuclear-quadrupole moment Q of hyperfine-probe-nuclear states of three different In isotopes: the 5 + 192 keV excited state of 114 In (probe for nuclear quadrupole alignment spectroscopy), the 9/2 + ground state of 115 In (nuclear magnetic and nuclear quadrupole resonance probe), and the 3/2 + 659 keV excited state of 117 In (perturbed angular correlations probe). These nuclear-quadrupole moments were determined by comparing experimental nuclear-quadrupole frequencies to the electric field gradient tensor calculated with high accuracy at In sites in metallic indium within the density functional theory. These ab initio calculations were performed with the full-potential linearized augmented plane wave method. The results obtained for the quadrupole moments of 114 In [Q( 114 In)=-0.14(1) b] are in clear discrepancy with those reported in the literature [Q( 114 In)=+0.16(6) b and +0.739(12) b]. For 115 In and 117 In our results are in excellent agreement with the literature and in the last case Q( 117 In) is determined with more precision. In the case of Q( 117 In), its sign cannot be determined because standard γ-γ perturbed angular correlations experiments are not sensitive to the sign of the nuclear-quadrupole frequency

Correlation functions of electronic and nuclear spins in a Heisenberg antiferromagnet semi-infinite media

International Nuclear Information System (INIS)

Sarmento, E.F.

1980-01-01

Results are found for the correlation dynamic functions (or the correspondent green functions) between any combination including pairs of electronic anel nuclear spin operators in an antiferromagnet semi-infinite media., at low temperature T N . These correlation functions, are used to investigate, at the same time, the properties of surface spin waves in volume and surface. The dispersion relatons of nuclear and electronic spin waves coupled modes, in surface are found, resolving a system of linearized equatons of spin operators a system of linearized equations of spin operators. (author) [pt

Boundary between the thermal and statistical polarization regimes in a nuclear spin ensemble

International Nuclear Information System (INIS)

Herzog, B. E.; Cadeddu, D.; Xue, F.; Peddibhotla, P.; Poggio, M.

2014-01-01

As the number of spins in an ensemble is reduced, the statistical fluctuations in its polarization eventually exceed the mean thermal polarization. This transition has now been surpassed in a number of recent nuclear magnetic resonance experiments, which achieve nanometer-scale detection volumes. Here, we measure nanometer-scale ensembles of nuclear spins in a KPF 6 sample using magnetic resonance force microscopy. In particular, we investigate the transition between regimes dominated by thermal and statistical nuclear polarization. The ratio between the two types of polarization provides a measure of the number of spins in the detected ensemble.

Core Technology Development of Nuclear spin polarization

International Nuclear Information System (INIS)

Yoo, Byung Duk; Gwon, Sung Ok; Kwon, Duck Hee; Lee, Sung Man

2009-12-01

In order to study nuclear spin polarization, we need several core technologies such as laser beam source to polarize the nuclear spin, low pressured helium cell development whose surface is essential to maintain polarization otherwise most of the polarized helium relaxed in short time, development of uniform magnetic field system which is essential for reducing relaxation, efficient vacuum system, development of polarization measuring system, and development of pressure raising system about 1000 times. The purpose of this study is to develop resonable power of laser system, that is at least 5 watt, 1083 nm, 4GHz tuneable. But the limitation of this research fund enforce to develop amplifying system into 5 watt with 1 watt system utilizing laser-diod which is already we have in stock. We succeeded in getting excellent specification of fiber laser system with power of 5 watts, 2 GHz linewidth, more than 80 GHz tuneable

Angstrom-Resolution Magnetic Resonance Imaging of Single Molecules via Wave-Function Fingerprints of Nuclear Spins

Science.gov (United States)

Ma, Wen-Long; Liu, Ren-Bao

2016-08-01

Single-molecule sensitivity of nuclear magnetic resonance (NMR) and angstrom resolution of magnetic resonance imaging (MRI) are the highest challenges in magnetic microscopy. Recent development in dynamical-decoupling- (DD) enhanced diamond quantum sensing has enabled single-nucleus NMR and nanoscale NMR. Similar to conventional NMR and MRI, current DD-based quantum sensing utilizes the "frequency fingerprints" of target nuclear spins. The frequency fingerprints by their nature cannot resolve different nuclear spins that have the same noise frequency or differentiate different types of correlations in nuclear-spin clusters, which limit the resolution of single-molecule MRI. Here we show that this limitation can be overcome by using "wave-function fingerprints" of target nuclear spins, which is much more sensitive than the frequency fingerprints to the weak hyperfine interaction between the targets and a sensor under resonant DD control. We demonstrate a scheme of angstrom-resolution MRI that is capable of counting and individually localizing single nuclear spins of the same frequency and characterizing the correlations in nuclear-spin clusters. A nitrogen-vacancy-center spin sensor near a diamond surface, provided that the coherence time is improved by surface engineering in the near future, may be employed to determine with angstrom resolution the positions and conformation of single molecules that are isotope labeled. The scheme in this work offers an approach to breaking the resolution limit set by the "frequency gradients" in conventional MRI and to reaching the angstrom-scale resolution.

The domestication of nuclear spins by chemists and biologists

CERN Document Server

Ernst, R

1992-01-01

The usage of nuclear spins in chemistry and biology for exploring the structure and dynamics of matter is discussed. The main emphasis is put on the methodological aspects of multidimensional nuclear magnetic resonance (NMR) spectroscopy that are responsible for the success of this powerful analytical technique.

Description of nuclear collective motion by Wigner function moments

International Nuclear Information System (INIS)

Balbutsev, E.B.

1996-01-01

The method is presented in which the collective motion is described by the dynamic equations for the nuclear integral characteristics. The 'macroscopic' dynamics is formulated starting from the equations of the microscopic theory. This is done by taking the phase space moments of the Wigner function equation. The theory is applied to the description of collective excitations with multipolarities up to λ=5. (author)

Nuclear orientation as a tool for studying the structure of very unstable nuclei

International Nuclear Information System (INIS)

Wood, J.L.

1985-01-01

With the availability of modern isotope separator on-line systems it has become possible to make broad and systematic studies of low-energy low-spin nuclear structure. A vital ingredient in such a program is unique spin-parity assignments to all low-lying levels. A most desirable complement to spin-parity information is detailed spectroscopic information. Obtaining such information far from stability is difficult because of low activity production. Nuclear orientation provides a means for obtaining spin assignments using singles measurements. This is less demanding on source intensities than γ-γ angular correlation coincidence measurements. Further, nuclear orientation can provide information on magnetic moments and on multipole mixing ratios. A number of structural problems are discussed: the need for unique spin assignments in systematics schemes; the need to distinguish between E2+E0 and M1 transitions; the importance of measuring E2-M1 mixing ratios; and the value of magnetic moment information. Particular emphasis is placed on the desirability of obtaining such information in the neutron-deficient Pt, Au, Hg, Tl, Pb and Bi isotopes, based upon the experimental program at the UNISOR facility. (Auth.)

Nuclear spin states and quantum logical operations

International Nuclear Information System (INIS)

Orlova, T.A.; Rasulov, E.N.

2006-01-01

Full text: To build a really functional quantum computer, researchers need to develop logical controllers known as 'gates' to control the state of q-bits. In this work , equal quantum logical operations are examined with the emphasis on 1-, 2-, and 3-q-bit gates.1-q-bit quantum logical operations result in Boolean 'NOT'; the 'NOT' and '√NOT' operations are described from the classical and quantum perspective. For the 'NOT' operation to be performed, there must be a means to switch the state of q-bits from to and vice versa. For this purpose either a light or radio pulse of a certain frequency can be used. If the nucleus has the spin-down state, the spin will absorb a portion of energy from electromagnetic current and switch into the spin-up state, and the radio pulse will force it to switch into state. An operation thus described from purely classical perspective is clearly understood. However, operations not analogous to the classical type may also be performed. If the above mentioned radio pulses are only half the frequency required to cause a state switch in the nuclear spin, the nuclear spin will enter the quantum superposition state of the ground state (↓) and excited states (↑). A recurring radio pulse will then result in an operation equivalent to 'NOT', for which reason the described operation is called '√NOT'. Such an operation allows for the state of quantum superposition in quantum computing, which enables parallel processing of several numbers. The work also treats the principles of 2-q-bit logical operations of the controlled 'NOT' type (CNOT), 2-q-bit (SWAP), and the 3-q-bit 'TAFFOLI' gate. (author)

On the properties of nuclear matter with an excess of neutrons, spin-up neutrons and spin-up protons using effective nucleon-nucleon potential

International Nuclear Information System (INIS)

Hassan, M.Y.; Ramadan, S.

1978-01-01

The binding energy of nuclear matter with an excess of neutrons, with spin-up neutrons and spin-up protons (characterized by the corresponding parameters αsub(tau)=(N-Z)/A, αsub(n)=(N(up)-N(down))/A, and αsub(p)=(Z(up)-Z(down))/A) contains three symmetry energies: the isospin symmetry energy epsilon sub(tau), the spin symmetry energy epsilon sub(sigma) and the spin-isospin symmetry energy epsilon sub(sigma tau). These energies are calculated using velocity-dependent effective potential of s-wave interaction, which was developed by Dzhibuti and Mamasakhlisov. The spin, isospin and spin-isospin dependent parts of the single-particle potential in nuclear matter are also calculated using the same effective nucleon-nucleon potentials. The spin-spin part of the optical model potential is estimated. (author)

Theory for cross effect dynamic nuclear polarization under magic-angle spinning in solid state nuclear magnetic resonance: the importance of level crossings.

Science.gov (United States)

Thurber, Kent R; Tycko, Robert

2012-08-28

We present theoretical calculations of dynamic nuclear polarization (DNP) due to the cross effect in nuclear magnetic resonance under magic-angle spinning (MAS). Using a three-spin model (two electrons and one nucleus), cross effect DNP with MAS for electron spins with a large g-anisotropy can be seen as a series of spin transitions at avoided crossings of the energy levels, with varying degrees of adiabaticity. If the electron spin-lattice relaxation time T(1e) is large relative to the MAS rotation period, the cross effect can happen as two separate events: (i) partial saturation of one electron spin by the applied microwaves as one electron spin resonance (ESR) frequency crosses the microwave frequency and (ii) flip of all three spins, when the difference of the two ESR frequencies crosses the nuclear frequency, which transfers polarization to the nuclear spin if the two electron spins have different polarizations. In addition, adiabatic level crossings at which the two ESR frequencies become equal serve to maintain non-uniform saturation across the ESR line. We present analytical results based on the Landau-Zener theory of adiabatic transitions, as well as numerical quantum mechanical calculations for the evolution of the time-dependent three-spin system. These calculations provide insight into the dependence of cross effect DNP on various experimental parameters, including MAS frequency, microwave field strength, spin relaxation rates, hyperfine and electron-electron dipole coupling strengths, and the nature of the biradical dopants.

Effects of nuclear spins on the transport properties of the edge of two-dimensional topological insulators

Science.gov (United States)

Hsu, Chen-Hsuan; Stano, Peter; Klinovaja, Jelena; Loss, Daniel

2018-03-01

The electrons in the edge channels of two-dimensional topological insulators can be described as a helical Tomonaga-Luttinger liquid. They couple to nuclear spins embedded in the host materials through the hyperfine interaction, and are therefore subject to elastic spin-flip backscattering on the nuclear spins. We investigate the nuclear-spin-induced edge resistance due to such backscattering by performing a renormalization-group analysis. Remarkably, the effect of this backscattering mechanism is stronger in a helical edge than in nonhelical channels, which are believed to be present in the trivial regime of InAs/GaSb quantum wells. In a system with sufficiently long edges, the disordered nuclear spins lead to an edge resistance which grows exponentially upon lowering the temperature. On the other hand, electrons from the edge states mediate an anisotropic Ruderman-Kittel-Kasuya-Yosida nuclear spin-spin interaction, which induces a spiral nuclear spin order below the transition temperature. We discuss the features of the spiral order, as well as its experimental signatures. In the ordered phase, we identify two backscattering mechanisms, due to charge impurities and magnons. The backscattering on charge impurities is allowed by the internally generated magnetic field, and leads to an Anderson-type localization of the edge states. The magnon-mediated backscattering results in a power-law resistance, which is suppressed at zero temperature. Overall, we find that in a sufficiently long edge the nuclear spins, whether ordered or not, suppress the edge conductance to zero as the temperature approaches zero.

Nuclear structure studies on indium and tin isotope chains by means of laser spectroscopy

International Nuclear Information System (INIS)

Eberz, J.

1986-11-01

In a collaboration with GSI in Darmstadt and ISOLDE in Geneva the hyperfine structure (HFS) and the isotope shift (IS) of the indium isotopes from 104 In - 127 In in their ground and isomeric states could be studied. Additionally the tin isotopes 109 Sn and 111 Sn could be measured. In tin the transition 5p 2 1 S 0 → 5p6s 3 P 1 with λ = 563 nm was studied. In indium the transition 5p 2 P 1/2 → 6s 2 S 1/2 with λ = 410 nm and 5p 2 P 3/2 → 6s 2 S 1/2 with λ = 451 nm could be measured. The magnetic dipole moments and electric quadrupole moments determined from the measurements of the HFS can be sufficiently explained in the framework of the single-particle model. From the moments the configurations and spins of the studied nuclear states can be stated. In 109 Sn the nuclear spin was determined to I = 5/2. The measurement of the IS in two lines in 108 In allowed regarding the coupling rules for nuclear moments the determination of the nuclear spin. The spin of the 40 m isomers of the 108m In can be stated to I = 2. The mean square nuclear charge radius exhibits a parabolic slope the quadratic part of which with a maximum in the shell center at N = 66 between the neutron numbers N = 50 and N = 82 can be understood as sum of contributions of a surface correlation, i.e. a quadrupole deformation as well as eventually present higher order terms or a change of the surface skin density. The deformation determinable by this description is both for tin and for indium essentially larger than the deformation from the B(E2) values of tin or from the intrinsic quadrupole moments in indium derived from the HFS. (orig./HSI) [de

Thermal coupling in low fields between the nuclear and electronic spins in Tm2+ doped CaF2

International Nuclear Information System (INIS)

Urbina, Cristian.

1977-01-01

It is shown that in a CaF 2 crystal doped with divalent thulium ions there is in low fields, a thermal coupling between the electron magnetic moments of Tm 2+ and the nuclear moments of 19 F. When these ones have been lowered down to temperature through dynamical high-field polarization and adiabatic demagnetization in succession the resulting polarisation of the formed ones can overstep their original polarization in high field. A trial is given to explain this Zeeman electronic energy cooling through nuclear Zeeman energy with invoking a thermal coupling between both systems through the spin-spin electronic interaction but no theoretical model is developed in view of a quantitative explanation of the dynamics of such a process. The magnetic resonance spectrum of Tm 2 + in low field is also investigated: an important shift and narrowing of the electron resonance line in low field are obtained when 19 F nuclei are very cold. This special spectral characters are explained as due to magnetic interactions between electronic impurities and the neighbouring 19 F nuclei and a theoretical model is developed (based on the local Weiss field approximation) which explains rather well the changes in the spectral shift as a function of the 19 F nucleus temperature. A second theoretical model has also been developed in view of a quantitative explanation of both the narrowing and shift of the spectrum, but its prediction disagree with the experimental results. It is shown that in low fieldsx it is possible to get rid of paramagnetic impurities after they have been reused as reducing agents for 19 F nucleus entropy populating at about 80%, a non magnetic metastable state with these impurities [fr

The origin of nuclear spin and its effect durning intermediate energy heavy ion collisions

International Nuclear Information System (INIS)

Zhang Guoqiang; Cao Xiguang; Fu Yao; Ma Yugang; Cai Xiangzhou; Wang Hongwei; Fang Deqing; Tian Wendong; Chen Jingen; Guo Wei; Liu Guihua

2010-01-01

We use the heavy-ion phase-space exploration (HIPSE) model to discuss the origin of the nuclear spin and its effect in Intermediate energy nuclear reaction. It is found that the spin of projectile depends on the impact parameter of the reaction system heavily, while on the violence lightly by contrast. Some interesting multifragmentation phenomena related to the spin are shown, especially those of phase transition. At the same time, the role of excited energy for multifragmentation is also invested. We find the later plays a more robust role durning the nuclear disintegration. (authors)

Measuring nuclear-spin-dependent parity violation with molecules: Experimental methods and analysis of systematic errors

Science.gov (United States)

Altuntaş, Emine; Ammon, Jeffrey; Cahn, Sidney B.; DeMille, David

2018-04-01

Nuclear-spin-dependent parity violation (NSD-PV) effects in atoms and molecules arise from Z0 boson exchange between electrons and the nucleus and from the magnetic interaction between electrons and the parity-violating nuclear anapole moment. It has been proposed to study NSD-PV effects using an enhancement of the observable effect in diatomic molecules [D. DeMille et al., Phys. Rev. Lett. 100, 023003 (2008), 10.1103/PhysRevLett.100.023003]. Here we demonstrate highly sensitive measurements of this type, using the test system 138Ba19F. We show that systematic errors associated with our technique can be suppressed to at least the level of the present statistical sensitivity. With ˜170 h of data, we measure the matrix element W of the NSD-PV interaction with uncertainty δ W /(2 π )<0.7 Hz for each of two configurations where W must have different signs. This sensitivity would be sufficient to measure NSD-PV effects of the size anticipated across a wide range of nuclei.

Local moment formation in Dirac electrons

International Nuclear Information System (INIS)

Mashkoori, M; Mahyaeh, I; Jafari, S A

2015-01-01

Elemental bismuth and its compounds host strong spin-orbit interaction which is at the heart of topologically non-trivial alloys based on bismuth. These class of materials are described in terms of 4x4 matrices at each v point where spin and orbital labels of the underlying electrons are mixed. In this work we investigate the single impurity Anderson model (SIAM) within a mean field approximation to address the nature of local magnetic moment formation in a generic Dirac Hamiltonian. Despite the spin-mixing in the Hamiltonian, within the Hartree approximation it turns out that the impuritys Green function is diagonal in spin label. In the three dimensional Dirac materials defined over a bandwidth D and spin-orbit parameter γ, that hybridizes with impurity through V, a natural dimensionless parameter V 2 D/2πγ 3 emerges. So neither the hybridization strength, V, nor the spin-orbit coupling γ, but a combination thereof governs the phase diagram. By tuning chemical potential and the impurity level, we present phase diagram for various values of Hubbard U. Numerical results suggest that strong spin-orbit coupling enhances the local moment formation both in terms of its strength and the area of the local moment region. In the case that we tune the chemical potential in a similar way as normal metal we find that magnetic region is confined to μ ≥ ε 0 , in sharp contrast to 2D Dirac fermions. If one fixes the chemical potential and tunes the impurity level, phase diagram has two magnetic regions which corresponds to hybridization of impurity level with lower and upper bands. (paper)

Fits of the baryon magnetic moments to the quark model and spectrum-generating SU(3)

International Nuclear Information System (INIS)

Bohm, A.; Teese, R.B.

1982-01-01

We show that for theoretical as well as phenomenological reasons the baryon magnetic moments that fulfill simple group transformation properties should be taken in intrinsic rather than nuclear magnetons. A fit of the recent experimental data to the reduced matrix elements of the usual octet electromagnetic current is still not good, and in order to obtain acceptable agreement, one has to add correction terms to the octet current. We have texted two kinds of corrections: U-spin-scalar terms, which are singles out by the model-independent algebraic properties of the hadron electromagnetic current, and octet U-spin vectors, which could come from quark-mass breaking in a nonrelativistic quark model. We find that the U-spin-scalar terms are more important than the U-spin vectors for various levels of demanded theoretical accuracy

Laser measurements and nuclear structure

International Nuclear Information System (INIS)

Leander, G.A.

1982-01-01

The nuclear states amenable to laser studies are reviewed with respect to their structure. Systematic predictions are made, e.g., for magnetic moments of parity-mixed intrinsic orbitals in the Ac isotopes and for the shape of the known high-spin isomers in the Pb region

Spin-off strategies for the improvement of the performance national nuclear R and D project

International Nuclear Information System (INIS)

Lee, T. J.; Kim, H. J.; Jung, H. S.; Yang, M. H.; Choi, Y. M.

1998-01-01

In the light of the strategic utilization of the national R and D projects, this paper is to induce the spin-off strategies to improve the national R and D effectiveness through analyzing the spin-off characteristics of nuclear technologies, the spin-off status of the advanced countries and the case study of Korean nuclear spin-offs. Spin-off process is viewed as a three-stage operation, such as preparation stage, implementation stage and maintenance stage. In order to find the correlation between the influencing factors and spin-off effectiveness, the Spearman's correlation coefficient was employed as a specific statistical technique. By integrating this correlation, spin-off process and spin-off strategies, this paper presents an efficient frame work to improve the spin-off effectiveness

International conference on spin observables of nuclear probes: Summary talk

International Nuclear Information System (INIS)

Garvey, G.T.

1988-01-01

A selected summary of the presentation and discussions at the 4th Telluride Conference is presented. The summary deals mainly with the effects of nuclear spin and isospin on the interaction between nucleons and their consequences in nuclear structure. 11 figs

On multipole moments in general relativity

International Nuclear Information System (INIS)

Hoenselaers, C.

1986-01-01

In general situations, involving gravitational waves the question of multiple moments in general relativity restricts the author to stationary axisymmetric situations. Here it has been shown that multipole moments, a set of numbers defined at spatial infinity as far away from the source as possible, determine a solution of Einstein's equations uniquely. With the rather powerful methods for generating solutions one might hope to get solutions with predefined multipole moments. Before doing so, however, one needs an efficient algorithm for calculating the moments of a given solution. Chapter 2 deals with a conjecture pertaining to such a calculational procedure and shows it to be not true. There is another context in which multipole moments are important. Consider a system composed of several objects. To separate, if possible, the various parts of their interaction, one needs a definition for multipole moments of individual members of a many body system. In spite of the fact that there is no definition for individual moments, with the exception of mass and angular momentum, Chapter 3 shows what can be done for the double Kerr solution. The authors can identify various terms in he interaction of two aligned Kerr objects and show that gravitational spin-spin interaction is indeed proportional to the product of the angular momenta

Variational approach to magnetic moments

Energy Technology Data Exchange (ETDEWEB)

Lipparini, E; Stringari, S; Traini, M [Dipartimento di Matematica e Fisica, Libera Universita di Trento, Italy

1977-11-07

Magnetic moments in nuclei with a spin unsaturated core plus or minus an extra nucleon have been studied using a restricted Hartree-Fock approach. The method yields simple explicit expressions for the deformed ground state and for magnetic moments. Different projection techniques of the HF scheme have been discussed and compared with perturbation theory.

Nuclear charge radii and nuclear moments of neutron deficient Ba isotopes from high resolution laser spectroscopy

International Nuclear Information System (INIS)

Nowicki, G.; Bekk, K.; Goering, S.; Hanser, A.; Rebel, H.; Schatz, G.

1978-07-01

Isotope shifts and hyperfine structure of the BaI 6s 2 1 S 0 -6s6p 1 P 1 transitions (lambda = 553.6 nm) in neutron deficient Ba nuclides (N 131 Ba, 128 Ba, in addition to remeasurements of all stable Ba nuclides. The extracted values of delta 2 >, the observed odd-even staggering and the nuclear moments are discussed in the light of other theoretical and experimental nuclear structure studies of the region 50 [de

Magnetic moment, vorticity-spin coupling and parity-odd conductivity of chiral fermions in 4-dimensional Wigner functions

Energy Technology Data Exchange (ETDEWEB)

Gao, Jian-hua [Shandong Provincial Key Laboratory of Optical Astronomy and Solar-Terrestrial Environment, Institute of Space Sciences, Shandong University, Weihai, Shandong 264209 (China); Wang, Qun, E-mail: qunwang@ustc.edu.cn [Interdisciplinary Center for Theoretical Study and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China); Physics Department, Brookhaven National Laboratory, Upton, NY 11973-5000 (United States)

2015-10-07

We demonstrate the emergence of the magnetic moment and spin-vorticity coupling of chiral fermions in 4-dimensional Wigner functions. In linear response theory with space–time varying electromagnetic fields, the parity-odd part of the electric conductivity can also be derived which reproduces results of the one-loop and the hard-thermal or hard-dense loop. All these properties show that the 4-dimensional Wigner functions capture comprehensive aspects of physics for chiral fermions in electromagnetic fields.

Magnus effects on spinning transonic missiles

Science.gov (United States)

Seginer, A.; Rosenwasser, I.

1983-01-01

Magnus forces and moments were measured on a basic-finner model spinning in transonic flow. Spin was induced by canted fins or by full-span or semi-span, outboard and inboard roll controls. Magnus force and moment reversals were caused by Mach number, reduced spin rate, and angle of attack variations. Magnus center of pressure was found to be independent of the angle of attack but varied with the Mach number and model configuration or reduced spin rate.

Spin-density correlations in the dynamic spin-fluctuation theory: Comparison with polarized neutron scattering experiments

Energy Technology Data Exchange (ETDEWEB)

Melnikov, N.B., E-mail: melnikov@cs.msu.su [Lomonosov Moscow State University, Moscow 119991 (Russian Federation); Reser, B.I., E-mail: reser@imp.uran.ru [Miheev Institute of Metal Physics, Ural Branch of Russian Academy of Sciences, Ekaterinburg 620990 (Russian Federation); Paradezhenko, G.V., E-mail: gparadezhenko@cs.msu.su [Lomonosov Moscow State University, Moscow 119991 (Russian Federation)

2016-08-01

To study the spin-density correlations in the ferromagnetic metals above the Curie temperature, we relate the spin correlator and neutron scattering cross-section. In the dynamic spin-fluctuation theory, we obtain explicit expressions for the effective and local magnetic moments and spatial spin-density correlator. Our theoretical results are demonstrated by the example of bcc Fe. The effective and local moments are found in good agreement with results of polarized neutron scattering experiment over a wide temperature range. The calculated short-range order is small (up to 4 Å) and slowly decreases with temperature.

Nuclear spin warm up in bulk n -GaAs

Science.gov (United States)

Kotur, M.; Dzhioev, R. I.; Vladimirova, M.; Jouault, B.; Korenev, V. L.; Kavokin, K. V.

2016-08-01

We show that the spin-lattice relaxation in n -type insulating GaAs is dramatically accelerated at low magnetic fields. The origin of this effect, which cannot be explained in terms of well-known diffusion-limited hyperfine relaxation, is found in the quadrupole relaxation, induced by fluctuating donor charges. Therefore, quadrupole relaxation, which governs low field nuclear spin relaxation in semiconductor quantum dots, but was so far supposed to be harmless to bulk nuclei spins in the absence of optical pumping, can be studied and harnessed in the much simpler model environment of n -GaAs bulk crystal.

Spectrum of spin waves in cold polarized gases

Energy Technology Data Exchange (ETDEWEB)

Andreeva, T. L., E-mail: phdocandreeva@yandex.ru [Russian Academy of Sciences, Lebedev Physical Institute (Russian Federation)

2017-02-15

The spin dynamics of cold polarized gases are investigated using the Boltzmann equation. The dispersion relation for spin waves (transverse component of the magnetic moment) and the spin diffusion coefficient of the longitudinal component of the magnetic moment are calculated without using fitting parameters. The spin wave frequency and the diffusion coefficient for rubidium atoms are estimated numerically.

Low-spin identical bands in odd-A nuclei

Energy Technology Data Exchange (ETDEWEB)

Baktash, C; Garrett, J D; Winchell, D F; Smith, A [Oak Ridge National Lab., TN (United States)

1992-08-01

A comprehensive study of odd-A rotational bands in normally-deformed rare-earth nuclei indicates that a large number of seniority-one configurations (30% for odd-Z nuclei) at low spin have moments of inertia nearly identical to that of the seniority-zero configuration of the neighboring even-even nucleus with one less nucleon. It is difficult to reconcile these results with conventional models, based on the traditional picture of nuclear pair correlation in vogue for more than three decades, which predict variations of about 15% in the moments of inertia of configurations differing by one unit in seniority. (author). 18 refs., 1 tab., 1 fig.

Low-spin identical bands in odd-A nuclei

International Nuclear Information System (INIS)

Baktash, C.; Garrett, J.D.; Winchell, D.F.; Smith, A.

1992-01-01

A comprehensive study of odd-A rotational bands in normally-deformed rare-earth nuclei indicates that a large number of seniority-one configurations (30% for odd-Z nuclei) at low spin have moments of inertia nearly identical to that of the seniority-zero configuration of the neighboring even-even nucleus with one less nucleon. It is difficult to reconcile these results with conventional models, based on the traditional picture of nuclear pair correlation in vogue for more than three decades, which predict variations of about 15% in the moments of inertia of configurations differing by one unit in seniority. (author). 18 refs., 1 tab., 1 fig

Spin-isotropic continuum of spin excitations in antiferromagnetically ordered Fe1.07Te

Science.gov (United States)

Song, Yu; Lu, Xingye; Regnault, L.-P.; Su, Yixi; Lai, Hsin-Hua; Hu, Wen-Jun; Si, Qimiao; Dai, Pengcheng

2018-02-01

Unconventional superconductivity typically emerges in the presence of quasidegenerate ground states, and the associated intense fluctuations are likely responsible for generating the superconducting state. Here we use polarized neutron scattering to study the spin space anisotropy of spin excitations in Fe1.07Te exhibiting bicollinear antiferromagnetic (AF) order, the parent compound of FeTe1 -xSex superconductors. We confirm that the low-energy spin excitations are transverse spin waves, consistent with a local-moment origin of the bicollinear AF order. While the ordered moments lie in the a b plane in Fe1.07Te , it takes less energy for them to fluctuate out of plane, similar to BaFe2As2 and NaFeAs. At energies above E ≳20 meV, we find magnetic scattering to be dominated by an isotropic continuum that persists up to at least 50 meV. Although the isotropic spin excitations cannot be ascribed to spin waves from a long-range-ordered local-moment antiferromagnet, the continuum can result from the bicollinear magnetic order ground state of Fe1.07Te being quasidegenerate with plaquette magnetic order.

Low-spin identical bands in neighboring odd-A and even-even nuclei

International Nuclear Information System (INIS)

Baktash, C.; Winchell, D.F.; Garrett, J.D.; Smith, A.

1992-01-01

A comprehensive study of odd-A rotational bands in normally deformed rare-earth nuclei indicates that a large number of seniority-one configurations (21% for odd-Z nuclei) at low spin have moments of inertia nearly identical to that of the seniority-zero configuration of the neighboring even-even nucleus with one less nucleon. It is difficult to reconcile these results with conventional models of nuclear pair correlation, which predict variations of about 15% in the moments of inertia of configurations differing by one unit in seniority

Quark-hadron duality of nucleon spin structure function

International Nuclear Information System (INIS)

Dong, Y.B.

2005-01-01

Bloom-Gilman quark-hadron duality of nuclear spin structure function is studied by comparing the integral of g 1 from perturbative QCD prediction in the scaling region to the moment of g 1 in the resonance region. The spin structure function in the resonance region is estimated by the parametrization forms of non-resonance background and of resonance contributions. The uncertainties of our calculations due to those parametrization forms are discussed. Moreover, the effect of the Δ(1232)-resonance in the first resonance region and the role of the resonances in the second resonance region are explicitly shown. Elastic peak contribution to the duality is also analyzed. (orig.)

Magnetic moment, vorticity-spin coupling and parity-odd conductivity of chiral fermions in 4-dimensional Wigner functions

Directory of Open Access Journals (Sweden)

Jian-hua Gao

2015-10-01

Full Text Available We demonstrate the emergence of the magnetic moment and spin-vorticity coupling of chiral fermions in 4-dimensional Wigner functions. In linear response theory with space–time varying electromagnetic fields, the parity-odd part of the electric conductivity can also be derived which reproduces results of the one-loop and the hard-thermal or hard-dense loop. All these properties show that the 4-dimensional Wigner functions capture comprehensive aspects of physics for chiral fermions in electromagnetic fields.

Muon spin relaxation and nonmagnetic Kondo state in PrInAg2

International Nuclear Information System (INIS)

MacLaughlin, D. E.; Heffner, R. H.; Nieuwenhuys, G. J.; Canfield, P. C.; Amato, A.; Baines, C.; Schenck, A.; Luke, G. M.; Fudamoto, Y.; Uemura, Y. J.

2000-01-01

Muon spin relaxation experiments have been carried out in the Kondo compound PrInAg 2 . The zero-field muon relaxation rate is found to be independent of temperature between 0.1 and 10 K, which rules out a magnetic origin (spin freezing or a conventional Kondo effect) for the previously observed specific-heat anomaly at ∼0.5 K. At low temperatures the muon relaxation can be quantitatively understood in terms of the muon's interaction with nuclear magnetism, including hyperfine enhancement of the 141 Pr nuclear moment at low temperatures. This argues against a Pr 3+ ground-state electronic magnetic moment, and is strong evidence for the doublet Γ 3 crystalline-electric-field-split ground state required for a nonmagnetic route to heavy-electron behavior. The data imply the existence of an exchange interaction between neighboring Pr 3+ ions of the order of 0.2 K in temperature units, which should be taken into account in a complete theory of a nonmagnetic Kondo effect in PrInAg 2 . (c) 2000 The American Physical Society

Nuclear spin dominated relaxation of atomic tunneling systems in glasses

Energy Technology Data Exchange (ETDEWEB)

Luck, Annina

2016-11-16

The measurements performed in this thesis have revealed a non phononic relaxation channel for atomic tunneling systems in glasses at very low temperatures due to the presence of nuclear electric quadrupoles. Dielectric measurements on the multicomponent glasses N-KZFS11 and HY-1, containing {sup 181}Ta and {sup 165}Ho, respectively, that both carry very large nuclear electric quadrupole moments, show a relaxation rate in the kilohertz range, that is constant for temperatures exceeding the nuclear quadrupole splitting of the relevant isotopes. The results are compared to measurements performed on the glasses Herasil and N-BK7 that both contain no large nuclear quadrupole moments. Using three different setups to measure the complex dielectric function, the measurements cover almost eight orders of magnitude in frequency from 60 Hz to 1 GHz and temperatures down to 7.5 mK. This has allowed us a detailed study of the novel effects observed within this thesis and has led to a simplified model explaining the effects of nuclear electric quadrupoles on the behavior of glasses at low temperatures. Numeric calculations based on this model are compared to the measured data.

Neutron-proton isovector pairing effect on the nuclear moment of inertia

International Nuclear Information System (INIS)

Mokhtari, D.; Ami, I.; Fellah, M.; Allal, N.H.

2008-01-01

The neutron-proton (n-p) isovector pairing effect on the nuclear moment of inertia has been studied within the framework of the BCS approximation. An analytical expression of the moment of inertia, that explicitly depends upon the n-p pairing, has been established using the Inglis cranking model. The model was first tested numerically for nuclei such as N = Z and whose experimental values of the moment of inertia are known (i.e. such as 16 ≤ Z ≤ 40). It has been shown that the n-p pairing effect is non-negligible and clearly improves the theoretical predictions when compared to those of the pairing between like particles. Secondly, predictions have been established for even-even proton-rich rare-earth nuclei. It has been shown that the n-p pairing effect is non-negligible when N = Z and rapidly decreases with increasing values of (N-Z). (author)

Quantum tunneling of the magnetic moment in a free nanoparticle

International Nuclear Information System (INIS)

O'Keeffe, M.F.; Chudnovsky, E.M.; Garanin, D.A.

2012-01-01

We study tunneling of the magnetic moment in a particle that has full rotational freedom. Exact energy levels are obtained and the ground-state magnetic moment is computed for a symmetric rotor. The effect of mechanical freedom on spin tunneling manifests itself in a strong dependence of the magnetic moment on the moments of inertia of the rotor. The energy of the particle exhibits quantum phase transitions between states with different values of the magnetic moment. Particles of various shapes are investigated and the quantum phase diagram is obtained. - Highlights: ► We obtain an exact analytical solution of a tunneling spin in a mechanical rotator. ► The quantum phase diagram shows magnetic moment dependence on rotator shape and size. ► Our work explains magnetic properties of free atomic clusters and magnetic molecules.

Analysis of dynamical corrections to baryon magnetic moments

International Nuclear Information System (INIS)

Ha, Phuoc; Durand, Loyal

2003-01-01

We present and analyze QCD corrections to the baryon magnetic moments in terms of the one-, two-, and three-body operators which appear in the effective field theory developed in our recent papers. The main corrections are extended Thomas-type corrections associated with the confining interactions in the baryon. We investigate the contributions of low-lying angular excitations to the baryon magnetic moments quantitatively and show that they are completely negligible. When the QCD corrections are combined with the nonquark model contributions of the meson loops, we obtain a model which describes the baryon magnetic moments within a mean deviation of 0.04 μ N . The nontrivial interplay of the two types of corrections to the quark-model magnetic moments is analyzed in detail, and explains why the quark model is so successful. In the course of these calculations, we parametrize the general spin structure of the j=(1/2) + baryon wave functions in a form which clearly displays the symmetry properties and the internal angular momentum content of the wave functions, and allows us to use spin-trace methods to calculate the many spin matrix elements which appear in the expressions for the baryon magnetic moments. This representation may be useful elsewhere

Quantum information generation, storage and transmission based on nuclear spins

Science.gov (United States)

Zaharov, V. V.; Makarov, V. I.

2018-05-01

A new approach to quantum information generation, storage and transmission is proposed. It is shown that quantum information generation and storage using an ensemble of N electron spins encounter unresolvable implementation problems (at least at the present time). As an alternative implementation we discuss two promising radical systems, one with N equivalent nuclear spins and another with N nonequivalent nuclear spins. Detailed analysis shows that only the radical system containing N nonequivalent nuclei is perfectly matched for quantum information generation, storage and transmission. We develop a procedure based on pulsed electron paramagnetic resonance (EPR) and we apply it to the radical system with the set of nonequivalent nuclei. The resulting EPR spectrum contains 2N transition lines, where N is the number of the atoms with the nuclear spin 1/2, and each of these lines may be encoded with a determined qudit sequence. For encoding the EPR lines we propose to submit the radical system to two magnetic pulses in the direction perpendicular to the z axis of the reference frame. As a result, the radical system impulse response may be measured, stored and transmitted through the communications channel. Confirming our development, the ab initio analysis of the system with three anion radicals was done showing matching between the simulations and the theoretical predictions. The developed method may be easily adapted for quantum information generation, storage, processing and transmission in quantum computing and quantum communications applications.

Noncommutative QED and anomalous dipole moments

International Nuclear Information System (INIS)

Riad, I.F.; Sheikh-Jabbari, M.M.

2000-09-01

We study QED on noncommutative spaces, NCQED. In particular we present the detailed calculation for the noncommutative electron-photon vertex and show that the Ward identity is satisfied. We discuss that in the noncommutative case moving electron will show electric dipole effects. In addition, we work out the electric and magnetic dipole moments up to one loop level. For the magnetic moment we show that noncommutative electron has an intrinsic (spin independent) magnetic moment. (author)

Low-spin identical bands in neighboring odd-A and even-even nuclei

International Nuclear Information System (INIS)

Baktash, C.; Winchell, D.F.; Garrett, J.D.; Smith, A.

1993-01-01

A comprehensive study of odd-A rotational bands in normally deformed rare-earth nuclei indicates that a large number of seniority-one configurations (21 % for odd-Z nuclei) at low spin have moments of inertia nearly identical to that of the seniority-zero configuration of the neighboring even-even nucleus with one less nucleon. It is difficult to reconcile these results with conventional models of nuclear pair correlation, which predict variations of about 15% in the moments of inertia of configurations differing by one unit in seniority. (orig.)

The total position-spread tensor: Spin partition

International Nuclear Information System (INIS)

El Khatib, Muammar; Evangelisti, Stefano; Leininger, Thierry; Brea, Oriana; Fertitta, Edoardo; Bendazzoli, Gian Luigi

2015-01-01

The Total Position Spread (TPS) tensor, defined as the second moment cumulant of the position operator, is a key quantity to describe the mobility of electrons in a molecule or an extended system. In the present investigation, the partition of the TPS tensor according to spin variables is derived and discussed. It is shown that, while the spin-summed TPS gives information on charge mobility, the spin-partitioned TPS tensor becomes a powerful tool that provides information about spin fluctuations. The case of the hydrogen molecule is treated, both analytically, by using a 1s Slater-type orbital, and numerically, at Full Configuration Interaction (FCI) level with a V6Z basis set. It is found that, for very large inter-nuclear distances, the partitioned tensor growths quadratically with the distance in some of the low-lying electronic states. This fact is related to the presence of entanglement in the wave function. Non-dimerized open chains described by a model Hubbard Hamiltonian and linear hydrogen chains H n (n ≥ 2), composed of equally spaced atoms, are also studied at FCI level. The hydrogen systems show the presence of marked maxima for the spin-summed TPS (corresponding to a high charge mobility) when the inter-nuclear distance is about 2 bohrs. This fact can be associated to the presence of a Mott transition occurring in this region. The spin-partitioned TPS tensor, on the other hand, has a quadratical growth at long distances, a fact that corresponds to the high spin mobility in a magnetic system

Multitudes of Stable States in a Periodically Driven Electron-Nuclear Spin System in a Quantum Dot

OpenAIRE

Korenev, V. L.

2010-01-01

The periodical modulation of circularly polarized light with a frequency close to the electron spin resonance frequency induces a sharp change of the single electron spin orientation. Hyperfine interaction provides a feedback, thus fixing the precession frequency of the electron spin in the external and the Overhauser field near the modulation frequency. The nuclear polarization is bidirectional and the electron-nuclear spin system (ENSS) possesses a few stable states. A similar frequency-loc...

On the properties of nuclear matter with an excess of neutrons, of spin-up neutrons and of spin-up protons using the Skyrme interaction

International Nuclear Information System (INIS)

Hassan, M.Y.M.; Ramadan, S.

1983-11-01

The binding energy of nuclear matter with an excess of neutrons, of spin-up neutrons, and of spin-up protons (characterized by the corresponding parameters, αsub(tau)=(N-Z/A), αsub(n)=(Nup-Ndown)/A, and αsub(rho)=(Zup-Zdown)/A), contains three symmetry energies: the isospin symmetry energy Esub(tau), the spin symmetry energy Esub(σ), and spin-isospin symmetry energy Esub(σtau). General expressions for Esub(σ), Esub(tau) and Esub(σtau) are given in the case of the Skyrme interaction. These values are compared with previous results obtained by Dabrowski and Haensel (DH) with Brueckner-Gammel-Thaler, the Hamada-Johnston, and the Reid soft core nucleon-nucleon potentials. The spin, isospin and spin-isospin dependent parts of the single-particle potential in nuclear matter are also calculated using the Skyrme interaction. The spin, isospin and spin-isospin incompressibility are calculated using the Skyrme interaction. The spin-spin part of the optical model potential is estimated. The results are compared with those of Dabrowski and Haensel (DH) and Hassan and Ramadan. (author)

Towards the improvement of spin-isospin properties in nuclear energy density functionals

International Nuclear Information System (INIS)

Roca-Maza, X.; Colò, G.; Liang, H. Z.; Sagawa, H.; Meng, J.; Ring, P.; Zhao, P. W.

2016-01-01

We address the problem of improving existing nuclear Energy Density Functionals (EDFs) in the spin-isospin channel. For that, we propose two different ways. The first one is to carefully take into account in the fitting protocol some of the key ground state properties for an accurate description of the most studied spin-isospin resonances: the Gamow-Teller Resonance (GTR) [1]. The second consists in providing a strategy to build local covariant EDF keeping the main features from their non-local counterparts [2]. The RHF model based on a Lagrangian where heavy mesons carry the nuclear effective interaction have been shown to be successful in the description of spin-isospin resonances [3]. (paper)

The statistic-thermodynamically calculations of magnetic thermodynamically functions for nuclear magnetic moments

International Nuclear Information System (INIS)

Zhu Zhenghe; Luo Deli; Feng Kaiming

2013-01-01

The present work is to calculate the magnetic thermodynamically functions, i.e. energy, the intensity of magnetization, enthalpy, entropy and Gibbs function for nuclear magnetic moments of T, D and neutron n at 2 T and 1, 50, 100 and 150 K from partition functions. It is shown that magnetic saturation of thermonuclear plasma does not easily occur for nuclear magneton is only of 10 -3 of Bohr magneton. The work done by magnetic field is considerable. (authors)

Quadrupole moments of Cd and Zn nuclei: When solid-state, molecular, atomic, and nuclear theory meet

DEFF Research Database (Denmark)

Haas, Heinz; Sauer, Stephan P. A.; Hemmingsen, Lars Bo Stegeager

2017-01-01

The nuclear quadrupole moment (Q) of the 5/2+ isomeric state of 111Cd, of particular importance to the interpretation of Perturbed Angular Correlation experiments in condensed matter, was determined by combining existing PAC data with high-level ab initio (CCSD(T)) calculations for Cd-dimethyl an......The nuclear quadrupole moment (Q) of the 5/2+ isomeric state of 111Cd, of particular importance to the interpretation of Perturbed Angular Correlation experiments in condensed matter, was determined by combining existing PAC data with high-level ab initio (CCSD(T)) calculations for Cd...

Quantum tunneling of the magnetic moment in a free nanoparticle

Energy Technology Data Exchange (ETDEWEB)

O' Keeffe, M.F. [Physics Department, Lehman College, City University of New York, 250 Bedford Park Boulevard West, Bronx, New York, 10468-1589 (United States); Chudnovsky, E.M., E-mail: eugene.chudnovsky@lehman.cuny.edu [Physics Department, Lehman College, City University of New York, 250 Bedford Park Boulevard West, Bronx, New York, 10468-1589 (United States); Garanin, D.A. [Physics Department, Lehman College, City University of New York, 250 Bedford Park Boulevard West, Bronx, New York, 10468-1589 (United States)

2012-09-15

We study tunneling of the magnetic moment in a particle that has full rotational freedom. Exact energy levels are obtained and the ground-state magnetic moment is computed for a symmetric rotor. The effect of mechanical freedom on spin tunneling manifests itself in a strong dependence of the magnetic moment on the moments of inertia of the rotor. The energy of the particle exhibits quantum phase transitions between states with different values of the magnetic moment. Particles of various shapes are investigated and the quantum phase diagram is obtained. - Highlights: Black-Right-Pointing-Pointer We obtain an exact analytical solution of a tunneling spin in a mechanical rotator. Black-Right-Pointing-Pointer The quantum phase diagram shows magnetic moment dependence on rotator shape and size. Black-Right-Pointing-Pointer Our work explains magnetic properties of free atomic clusters and magnetic molecules.

Comparison of nuclear electric resonance and nuclear magnetic resonance in integer and fractional quantum Hall states

International Nuclear Information System (INIS)

Tomimatsu, Toru; Shirai, Shota; Hashimoto, Katsushi; Sato, Ken; Hirayama, Yoshiro

2015-01-01

Electric-field-induced nuclear resonance (NER: nuclear electric resonance) involving quantum Hall states (QHSs) was studied at various filling factors by exploiting changes in nuclear spins polarized at quantum Hall breakdown. Distinct from the magnetic dipole interaction in nuclear magnetic resonance, the interaction of the electric-field gradient with the electric quadrupole moment plays the dominant role in the NER mechanism. The magnitude of the NER signal strongly depends on whether electronic states are localized or extended. This indicates that NER is sensitive to the screening capability of the electric field associated with QHSs

Squeezing and entangling nuclear spins in helium 3

DEFF Research Database (Denmark)

Reinaudi, Gael; Sinatra, Alice; Dantan, Aurelien Romain

2007-01-01

We present a realistic model for transferring the squeezing or the entanglement of optical field modes to the collective ground state nuclear spin of 3He using metastability exchange collisions. We discuss in detail the requirements for obtaining good quantum state transfer efficiency and study t...

Masses, magnetic moments, QCD and proton spin structure

International Nuclear Information System (INIS)

Lipkin, H.J.

1990-10-01

This talk is dedicated to the memory of Andrei D. Sakharov. In addition to his well-known contributions to society, Sakharov was also a pioneer in spin physics and the application of the basic ideas of QCD to spin structure of hadrons. He took quarks seriously at the time when the particle physicists ridiculed the quark model. Immediately after the quark proposal Sakharov asked: 'Why is M Λ ≠ M Σ ? They contain the same quarks' His answer was 'Spin Physics! A flavor-dependent hyperfine interaction'. (author)

Solid state nuclear magnetic resonance: investigating the spins of nuclear related materials

International Nuclear Information System (INIS)

Charpentier, Th.

2007-10-01

The author reviews his successive research works: his research thesis work on the Multiple Quantum Magic Angle Spinning (MQMAS) which is a quadric-polar nucleus multi-quanta correlation spectroscopy method, the modelling of NMR spectra of disordered materials, the application to materials of interest for the nuclear industry (notably the glasses used for nuclear waste containment). He presents the various research projects in which he is involved: storing glasses, nuclear magnetic resonance in paramagnetism, solid hydrogen storing matrices, methodological and instrument developments in high magnetic field and high resolution solid NMR, long range distance measurement by solid state Tritium NMR (observing the structure and dynamics of biological complex systems at work)

Spin waves and spin instabilities in quantum plasmas

OpenAIRE

Andreev, P. A.; Kuz'menkov, L. S.

2014-01-01

We describe main ideas of method of many-particle quantum hydrodynamics allows to derive equations for description of quantum plasma evolution. We also present definitions of collective quantum variables suitable for quantum plasmas. We show that evolution of magnetic moments (spins) in quantum plasmas leads to several new branches of wave dispersion: spin-electromagnetic plasma waves and self-consistent spin waves. Propagation of neutron beams through quantum plasmas is also considered. Inst...

Electric quadrupole moments of neutron-rich nuclei {sup 32}Al and {sup 31}Al

Energy Technology Data Exchange (ETDEWEB)

Kameda, D., E-mail: kameda@ribf.riken.jp; Ueno, H. [RIKEN Nishina Center (Japan); Asahi, K.; Nagae, D.; Takemura, M.; Shimada, K. [Tokyo Institute of Technology, Department of Physics (Japan); Yoshimi, A.; Nagatomo, T.; Sugimoto, T. [RIKEN Nishina Center (Japan); Uchida, M.; Arai, T.; Takase, K.; Suda, S.; Inoue, T. [Tokyo Institute of Technology, Department of Physics (Japan); Murata, J.; Kawamura, H. [Rikkyo University, Department of Physics (Japan); Watanabe, H. [Australian National University, Department of Nuclear Physics (Australia); Kobayashi, Y.; Ishihara, M. [RIKEN Nishina Center (Japan)

2007-11-15

The electric quadrupole moments for the ground states of {sup 32}Al and {sup 31}Al have been measured by the {beta} ray-detected nuclear quadrupole resonance method. Spin-polarized {sup 32}Al and {sup 31}Al nuclei were obtained from the fragmentation of {sup 40}Ar projectiles at E/A = 95 MeV/nucleon, and were implanted in a single crystal {alpha}-Al{sub 2}O{sub 3} stopper. The measured Q moment of {sup 32}Al, |Q({sup 32}Al)| = 24(2) mb, is in good agreement with a conventional shell-model calculation with a full sd model space and empirical effective charges, while that of {sup 31}Al is considerably smaller than the sd calculations.

Interference elimination: nuclear spin in the cabin

International Nuclear Information System (INIS)

Anon.

1984-01-01

Constructed on Michael Faraday's cage principle, such cabins enable nuclear spin tomographs to operate undisturbed by foreign radiation. The working signals of these medical research apparatus are screened from the environment so that radio and television reception are not affected. Details are given of the structure of the cabin, of the prefabricated structural elements of non-magnetic materials (chromium-nickel steel). (Auth.)

Correlated calculations of indirect nuclear spin-spin coupling constants using second-order polarization propagator approximations: SOPPA and SOPPA(CCSD)

DEFF Research Database (Denmark)

Enevoldsen, Thomas; Oddershede, Jens; Sauer, Stephan P. A.

1998-01-01

We present correlated calculations of the indirect nuclear spin-spin coupling constants of HD, HF, H2O, CH4, C2H2, BH, AlH, CO and N2 at the level of the second-order polarization propagator approximation (SOPPA) and the second-order polarization propagator approximation with coupled-cluster sing...

Contribution to the study of thermal mixing between nuclear spin systems; Contribution a l'etude du melange thermique entre systemes de spins nucleaires

Energy Technology Data Exchange (ETDEWEB)

Goldmann, M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1967-02-15

This work describes methods of dynamic nuclear polarization in solids based on the thermal mixing between nuclear spin systems. The description of the thermal mixing processes involves most of the fundamental aspects of the spin temperature theory. The experiments, conducted with paradichlorobenzene and para-dibromobenzene, yield a detailed confirmation of the theoretical predictions. (author) [French] Ce travail decrit des methodes de polarisation dynamique nucleaire dans les solides basees sur le melange thermique entre systemes de spins nucleaires. La description des processus de melange thermique met en jeu la plupart des aspects fondamentaux de la theorie de la temperature de spin. Les experiences, realisees avec du paradichlorobenzene et du paradibromobenzene, apportent une confirmation detaillee des previsions theoriques. (auteur)

The determination of the in situ structure by nuclear spin contrast variation

Energy Technology Data Exchange (ETDEWEB)

Stuhrmann, H.B. [GKSS Forschungszentrum, Geesthacht (Germany); Nierhaus, K.H. [Max-Planch-Institut fuer Molekulare Genetik, Berlin (Germany)

1994-12-31

Polarized neutron scattering from polarized nuclear spins in hydrogenous substances opens a new way of contrast variation. The enhanced contrast due to proton spin polarization was used for the in situ structure determination of tRNA of the functional complex of the E.coli ribosome.

The determination of the in situ structure by nuclear spin contrast variation

International Nuclear Information System (INIS)

Stuhrmann, H.B.; Nierhaus, K.H.

1994-01-01

Polarized neutron scattering from polarized nuclear spins in hydrogenous substances opens a new way of contrast variation. The enhanced contrast due to proton spin polarization was used for the in situ structure determination of tRNA of the functional complex of the E.coli ribosome

RPA spin-isospin nuclear response in the deep inelastic region

International Nuclear Information System (INIS)

Alberico, W.M.; Molinari, A.; De Pace, A.; Johnson, M.B.; Ericson, M.

1985-11-01

The spin-isospin volume responses of a finite nucleus are evaluated in the RPA frame, utilizing a harmonic oscillator basis. Particular emphasis is given to the mixing between the longitudinal and transverse couplings, which arise at the nuclear surface. We show that it reduces somewhat the contrast between the two spin responses. We compare the calculated transverse response with the experimental one extracted from deep inelastic electron scattering

Nuclear physics

International Nuclear Information System (INIS)

Kamal, Anwar

2014-01-01

Explains the concepts in detail and in depth. Provides step-by-step derivations. Contains numerous tables and diagrams. Supports learning and teaching with numerous worked examples, questions and problems with answers. Sketches also the historical development of the subject. This textbook explains the experimental basics, effects and theory of nuclear physics. It supports learning and teaching with numerous worked examples, questions and problems with answers. Numerous tables and diagrams help to better understand the explanations. A better feeling to the subject of the book is given with sketches about the historical development of nuclear physics. The main topics of this book include the phenomena associated with passage of charged particles and radiation through matter which are related to nuclear resonance fluorescence and the Moessbauer effect., Gamov's theory of alpha decay, Fermi theory of beta decay, electron capture and gamma decay. The discussion of general properties of nuclei covers nuclear sizes and nuclear force, nuclear spin, magnetic dipole moment and electric quadrupole moment. Nuclear instability against various modes of decay and Yukawa theory are explained. Nuclear models such as Fermi Gas Model, Shell Model, Liquid Drop Model, Collective Model and Optical Model are outlined to explain various experimental facts related to nuclear structure. Heavy ion reactions, including nuclear fusion, are explained. Nuclear fission and fusion power production is treated elaborately.

A spin-orbital-entangled quantum liquid on a honeycomb lattice

Science.gov (United States)

Kitagawa, K.; Takayama, T.; Matsumoto, Y.; Kato, A.; Takano, R.; Kishimoto, Y.; Bette, S.; Dinnebier, R.; Jackeli, G.; Takagi, H.

2018-02-01

The honeycomb lattice is one of the simplest lattice structures. Electrons and spins on this simple lattice, however, often form exotic phases with non-trivial excitations. Massless Dirac fermions can emerge out of itinerant electrons, as demonstrated experimentally in graphene, and a topological quantum spin liquid with exotic quasiparticles can be realized in spin-1/2 magnets, as proposed theoretically in the Kitaev model. The quantum spin liquid is a long-sought exotic state of matter, in which interacting spins remain quantum-disordered without spontaneous symmetry breaking. The Kitaev model describes one example of a quantum spin liquid, and can be solved exactly by introducing two types of Majorana fermion. Realizing a Kitaev model in the laboratory, however, remains a challenge in materials science. Mott insulators with a honeycomb lattice of spin-orbital-entangled pseudospin-1/2 moments have been proposed, including the 5d-electron systems α-Na2IrO3 (ref. 5) and α-Li2IrO3 (ref. 6) and the 4d-electron system α-RuCl3 (ref. 7). However, these candidates were found to magnetically order rather than form a liquid at sufficiently low temperatures, owing to non-Kitaev interactions. Here we report a quantum-liquid state of pseudospin-1/2 moments in the 5d-electron honeycomb compound H3LiIr2O6. This iridate does not display magnetic ordering down to 0.05 kelvin, despite an interaction energy of about 100 kelvin. We observe signatures of low-energy fermionic excitations that originate from a small number of spin defects in the nuclear-magnetic-resonance relaxation and the specific heat. We therefore conclude that H3LiIr2O6 is a quantum spin liquid. This result opens the door to finding exotic quasiparticles in a strongly spin-orbit-coupled 5d-electron transition-metal oxide.

Methods for Computing Accurate Atomic Spin Moments for Collinear and Noncollinear Magnetism in Periodic and Nonperiodic Materials.

Science.gov (United States)

Manz, Thomas A; Sholl, David S

2011-12-13

The partitioning of electron spin density among atoms in a material gives atomic spin moments (ASMs), which are important for understanding magnetic properties. We compare ASMs computed using different population analysis methods and introduce a method for computing density derived electrostatic and chemical (DDEC) ASMs. Bader and DDEC ASMs can be computed for periodic and nonperiodic materials with either collinear or noncollinear magnetism, while natural population analysis (NPA) ASMs can be computed for nonperiodic materials with collinear magnetism. Our results show Bader, DDEC, and (where applicable) NPA methods give similar ASMs, but different net atomic charges. Because they are optimized to reproduce both the magnetic field and the chemical states of atoms in a material, DDEC ASMs are especially suitable for constructing interaction potentials for atomistic simulations. We describe the computation of accurate ASMs for (a) a variety of systems using collinear and noncollinear spin DFT, (b) highly correlated materials (e.g., magnetite) using DFT+U, and (c) various spin states of ozone using coupled cluster expansions. The computed ASMs are in good agreement with available experimental results for a variety of periodic and nonperiodic materials. Examples considered include the antiferromagnetic metal organic framework Cu3(BTC)2, several ozone spin states, mono- and binuclear transition metal complexes, ferri- and ferro-magnetic solids (e.g., Fe3O4, Fe3Si), and simple molecular systems. We briefly discuss the theory of exchange-correlation functionals for studying noncollinear magnetism. A method for finding the ground state of systems with highly noncollinear magnetism is introduced. We use these methods to study the spin-orbit coupling potential energy surface of the single molecule magnet Fe4C40H52N4O12, which has highly noncollinear magnetism, and find that it contains unusual features that give a new interpretation to experimental data.

Effect of superconductivity on spin dynamics in (Y/sub 1-x/Re/sub x/)Rh4B4

International Nuclear Information System (INIS)

Kumagai, K.; Fradin, F.Y.

1982-01-01

An adiabatic field-cycle method has been used to study spin dynamics of RE ions in (Y/sub 1-x/RE/sub x/)Rh 4 B 4 . Longitudinal dipolar fluctuations of RE moments are found to be the main source of the nuclear spin-lattice relaxation time of 11 B. The variation of T 1 in the superconducting state is attributed to the reduction of the electronic spin-relaxation time, tau/sub m/, which is mainly determined by the RKKY type interaction mediated by the conduction electrons. 3 figures

The 40th anniversary of the discovery of NMR-chemical shift and nuclear spin-spin coupling

International Nuclear Information System (INIS)

Zhu Zhenghe; Gou Qingquan

1989-01-01

After the discovery of NMR Phenomenon in the physics laboratories of E.M.Purcell at Harvard and F.Bloch at Stanford in 1946, W.G.Proctor and F.C.Yu made the successful discovery of NMR-chemical shift and nuclear spin-spin coupling at Stanford in 1950, Which brought NMR spectroscopy from the physics laboratory to the laboratories of many different fields. This is worth memorizing. Retrospecting the past 40 years, it is sure that chemical shift theory will be much more prosperous prospects

Exploring Localization in Nuclear Spin Chains

Science.gov (United States)

Wei, Ken Xuan; Ramanathan, Chandrasekhar; Cappellaro, Paola

2018-02-01

Characterizing out-of-equilibrium many-body dynamics is a complex but crucial task for quantum applications and understanding fundamental phenomena. A central question is the role of localization in quenching thermalization in many-body systems and whether such localization survives in the presence of interactions. Probing this question in real systems necessitates the development of an experimentally measurable metric that can distinguish between different types of localization. While it is known that the localized phase of interacting systems [many-body localization (MBL)] exhibits a long-time logarithmic growth in entanglement entropy that distinguishes it from the noninteracting case of Anderson localization (AL), entanglement entropy is difficult to measure experimentally. Here, we present a novel correlation metric, capable of distinguishing MBL from AL in high-temperature spin systems. We demonstrate the use of this metric to detect localization in a natural solid-state spin system using nuclear magnetic resonance (NMR). We engineer the natural Hamiltonian to controllably introduce disorder and interactions, and observe the emergence of localization. In particular, while our correlation metric saturates for AL, it slowly keeps increasing for MBL, demonstrating analogous features to entanglement entropy, as we show in simulations. Our results show that our NMR techniques, akin to measuring out-of-time correlations, are well suited for studying localization in spin systems.

External magnetic field induced anomalies of spin nuclear dynamics in thin antiferromagnetic films

International Nuclear Information System (INIS)

Tarasenko, S.V.

1995-01-01

It is shown that if the thickness of homogeneously magnetized plate of high-axial antiferromagnetic within H external magnetic field becomes lower the critical one, then the effect of dynamic magnetoelastic interaction on Soul-Nakamura exchange of nuclear spins results in formation of qualitatively new types of spreading nuclear spin waves no else compared neither within the model of unrestricted magnetic nor at H = 0 in case of thin plate of high-axial antiferromagnetic. 10 refs

Nuclear tests of lepton number and CP nonconservation

International Nuclear Information System (INIS)

Haxton, W.C.

1984-01-01

I will discuss two topics, double beta decay and time-reversal-odd nuclear moments, in which important questions of nuclear structure must be addressed. These problems are taken from a growing class of nuclear and atomic experiments in which the special properties of many-body systems are exploited to test properties of elementary particles. Nuclei can serve as filters for interactions by providing kinematic windows where only certain processes can occur and by isolating quantum numbers such as spin, isospin, and parity. In addition, the strengths of interesting interactions can be enhanced through the mixing of nearly degenerate levels in nuclei. However, the most important asset of nuclear and atomic experiments is their precision. For example, experiments searching for T-odd nuclear moments exploit techniques for measuring changes in atomic energies of 10 -22 eV. Such precision techniques will play an increasingly important role in particle physics. In the discussion of double beta decay and T-odd nuclear moments it will become clear that important nuclear structure issues must be resolved in order to fully exploit the experimental results. During this talk I will highlight this aspect. 29 references

Magnetotransport in Layered Dirac Fermion System Coupled with Magnetic Moments

Science.gov (United States)

Iwasaki, Yoshiki; Morinari, Takao

2018-03-01

We theoretically investigate the magnetotransport of Dirac fermions coupled with localized moments to understand the physical properties of the Dirac material EuMnBi2. Using an interlayer hopping form, which simplifies the complicated interaction between the layers of Dirac fermions and the layers of magnetic moments in EuMnBi2, the theory reproduces most of the features observed in this system. The hysteresis observed in EuMnBi2 can be caused by the valley splitting that is induced by the spin-orbit coupling and the external magnetic field with the molecular field created by localized moments. Our theory suggests that the magnetotransport in EuMnBi2 is due to the interplay among Dirac fermions, localized moments, and spin-orbit coupling.

Determination of nuclear spins of short-lived isotopes by laser induced fluorescence

International Nuclear Information System (INIS)

Buchinger, F.; Dabkiewicz, P.; Kremmling, H.; Kuehl, T.; Mueller, A.C.; Schuessler, H.A.

1980-01-01

The spins of several nuclear ground and isomeric states have been measured for a number of mercury isotopes. The fluorescent light from the 6s6p 3 P 1 state is observed at 2537 Angstroem after excitation with the frequency doubled output of a pulsed dye laser. Four different laser induced fluorescence techniques were tested for their applicability: double resonance, Hanle effect, time delayed integral Hanle beats, and time resolved quantum beats. The sensitivity and selectivity of these models are compared with emphasis on the determination of spins of nuclei far from beta-stability, where short half lives and low production yields restrict the number of available atoms. The experiments were carried out on-line with the ISOLDE isotope separator at CERN at densities as low as 10 6 atoms/cm 3 . Results for the very neutron deficient high spin mercury isomers with half lives of several seconds, but also for the ground states of the abundant low spin stable mercury isotopes, are given as examples. The test measurements determined the nuclear spins of the odd sup(185m-191m)Hg isomers to be I = 13/2. (orig.)

RKKY interaction in spin polarized armchair graphene nanoribbon

Energy Technology Data Exchange (ETDEWEB)

Rezania, Hamed, E-mail: rezania.hamed@gmail.com; Azizi, Farshad

2016-11-01

We present the Ruderman–Kittle–Kasuya–Yosida (RKKY) interaction in the presence of magnetic long range ordered armchair graphene nanoribbon. RKKY interaction as a function of distance between localized moments has been analyzed. It has been shown that a magnetic ordering along the z-axis mediates an anisotropic interaction which corresponds to a XXZ model interaction between two magnetic moments. In order to calculate the exchange interaction along arbitrary direction between two magnetic moments, we should obtain the static spin susceptibilities of armchair graphene nanoribbon. The spin susceptibility components are calculated using Green's function approach for tight binding model Hamiltonian. The effects of spin polarization on the dependence of exchange interaction on distance between moments are investigated via calculating correlation function of spin density operators. Our results show that the chemical potential impacts the spatial behavior of RKKY interaction. - Highlights: • Theoretical calculation of RKKY interaction of armchair graphene nanoribbon. • The investigation of the effect of spin polarization on RKKY interaction. • The investigation of electronic concentration on RKKY interaction of armchair graphene nanoribbon.

Evolution of nuclear structure in neutron-rich odd-Zn isotopes and isomers

Directory of Open Access Journals (Sweden)

C. Wraith

2017-08-01

Full Text Available Collinear laser spectroscopy was performed on Zn (Z=30 isotopes at ISOLDE, CERN. The study of hyperfine spectra of nuclei across the Zn isotopic chain, N=33–49, allowed the measurement of nuclear spins for the ground and isomeric states in odd-A neutron-rich nuclei up to N=50. Exactly one long-lived (>10 ms isomeric state has been established in each 69–79Zn isotope. The nuclear magnetic dipole moments and spectroscopic quadrupole moments are well reproduced by large-scale shell–model calculations in the f5pg9 and fpg9d5 model spaces, thus establishing the dominant term in their wave function. The magnetic moment of the intruder Iπ=1/2+ isomer in 79Zn is reproduced only if the νs1/2 orbital is added to the valence space, as realized in the recently developed PFSDG-U interaction. The spin and moments of the low-lying isomeric state in 73Zn suggest a strong onset of deformation at N=43, while the progression towards 79Zn points to the stability of the Z=28 and N=50 shell gaps, supporting the magicity of 78Ni.

Magnetic moments in present relativistic nuclear theories: a mean-field problem

International Nuclear Information System (INIS)

Desplanques, B.

1986-07-01

We show that the magnetic moments of LS closed shell nuclei plus or minus one nucleon derived from non-relativistic Hartree-Fock mean-fields are as bad as those obtained in relativistic approaches of nuclear structure. Deviations with respect to more complete results in both cases are ascribed to the mean-field approximation which neglects some degrees of freedom in the nucleus description. 18 refs

Zeeman perturbed nuclear quadrupole spin echo envelope modulations for spin 3/2 nuclei in polycrystalline specimens

Science.gov (United States)

Ramachandran, R.; Narasimhan, P. T.

The results of theoretical and experimental studies of Zeeman-perturbed nuclear quadrupole spin echo envelope modulations (ZSEEM) for spin 3/2 nuclei in polycrystalline specimens are presented. The response of the Zeeman-perturbed spin ensemble to resonant two pulse excitations has been calculated using the density matrix formalism. The theoretical calculation assumes a parallel orientation of the external r.f. and static Zeeman fields and an arbitrary orientation of these fields to the principal axes system of the electric field gradient. A numerical powder averaging procedure has been adopted to simulate the response of the polycrystalline specimens. Using a coherent pulsed nuclear quadrupole resonance spectrometer the ZSEEM patterns of the 35Cl nuclei have been recorded in polycrystalline specimens of potassium chlorate, barium chlorate, mercuric chloride (two sites) and antimony trichloride (two sites) using the π/2-τ-π/2 sequence. The theoretical and experimental ZSEEM patterns have been compared. In the case of mercuric chloride, the experimental 35Cl ZSEEM patterns are found to be nearly identical for the two sites and correspond to a near-zero value of the asymmetry parameter, η, of the electric field gradient tensor. The difference in the η values for the two 35Cl sites (η ˜0·06 and η˜0·16) in antimony trichloride is clearly reflected in the experimental and theoretical ZSEEM patterns. The present study indicates the feasibility of evaluating η for spin 3/2 nuclei in polycrystalline specimens from ZSEEM investigations.

Nuclear magnetic resonance (NMR): principles and applications

International Nuclear Information System (INIS)

Quibilan, E.I.

The basis for the phenomenon of nuclear magnetic resonance (NMR) is the ability of certain nuclei possessing both intrinsic angular momentum or ''spin'' I and magnetic moment to absorb electromagnetic energy in the radio frequency range. In principle, there are approximately 200 nuclei which may be investigated using the NMR technique. The NMR spectrum consists of intensity peaks along an axis calibrated in terms of the steady magnetic field or the frequency of the radiofrequency electromagnetic radiation. Analysis of the number, spacing, position and intensity of the lines in an NMR spectrum consists of intensity peaks along an axis calibrated in terms of the steady magnetic field or the frequency of the radiofrequency electromagnetic radiation. Analysis of the number, spacing, position and intensity of the lines in an NMR spectrum provides a variety of qualitative and quantitative analytical applications. The most obvious applications consist of the measurements of nuclear properties, such as spin number and nuclear magnetic moment. In liquids, the fine structure of resonance spectra provides a tool for chemical identification and molecular structure analysis. Other applications include the measurements of self-diffusion coefficients, magnetic fields and field homogeneity, inter-nuclear distances, and, in some cases, the water content of biological materials. (author)

Classical description of dynamical many-body systems with central forces, spin-orbit forces and spin-spin forces

International Nuclear Information System (INIS)

Goepfert, A.

1994-01-01

This thesis develops a new model, and related numerical methods, to describe classical time-dependent many-body systems interacting through central forces, spin-orbit forces and spin-spin forces. The model is based on two-particle interactions. The two-body forces consist of attractive and repulsive parts. In this model the investigated multi-particle systems are self-bound. Also the total potential of the whole ensemble is derived from the two-particle potential and is not imposed 'from outside'. Each particle has the three degrees of freedom of its centre-of-mass motion and the spin degree of freedom. The model allows for the particles to be either charged or uncharged. Furthermore, each particle has an angular momentum, an intrinsic spin, and a magnetic dipole moment. Through the electromagnetic forces between these charges and moments there arise dynamical couplings between them. The internal interactions between the charges and moments are well described by electromagnetic coupling mechanisms. In fact, compared to conventional classical molecular dynamics calculations in van der Waals clusters, which have no spin degrees of freedom, or for Heisenberg spin Systems, which have no orbital degrees of freedom, the model presented here contains both types of degrees of freedom with a highly non-trivial coupling. The model allows to study the fundamental effects resulting from the dynamical coupling of the spin and the orbital-motion sub-systems. In particular, the dynamics of the particle mass points show a behaviour basically different from the one of particles in a potential with only central forces. Furthermore, a special type of quenching procedure was invented, which tends to drive the multi-particle Systems into states with highly periodic, non-ergodic behaviour. Application of the model to cluster simulations has provided evidence that the model can also be used to investigate items like solid-to-liquid phase transitions (melting), isomerism and specific heat

Extended Moment Formation in Monolayer WS2 Doped with 3d Transition-Metals

KAUST Repository

Singh, Nirpendra

2016-08-30

First-principles calculations with onsite Coulomb interaction and spin-orbit coupling are used to investigate the electronic structure of monolayer WS2 doped substitutionally with 3d transition-metals. While neither W vacancies nor strain induce spin polarization, we demonstrate an unprecedented tendency to extended moment formation under doping. The extended magnetic moments are characterized by dopant-specific spin density patterns with rich structural features involving the nearest neighbor W and S atoms.

New Nuclear Magnetic Moment of 209Bi: Resolving the Bismuth Hyperfine Puzzle

Science.gov (United States)

Skripnikov, Leonid V.; Schmidt, Stefan; Ullmann, Johannes; Geppert, Christopher; Kraus, Florian; Kresse, Benjamin; Nörtershäuser, Wilfried; Privalov, Alexei F.; Scheibe, Benjamin; Shabaev, Vladimir M.; Vogel, Michael; Volotka, Andrey V.

2018-03-01

A recent measurement of the hyperfine splitting in the ground state of Li-like 80+208Bi has established a "hyperfine puzzle"—the experimental result exhibits a 7 σ deviation from the theoretical prediction [J. Ullmann et al., Nat. Commun. 8, 15484 (2017), 10.1038/ncomms15484; J. P. Karr, Nat. Phys. 13, 533 (2017), 10.1038/nphys4159]. We provide evidence that the discrepancy is caused by an inaccurate value of the tabulated nuclear magnetic moment (μI) of 209Bi. We perform relativistic density functional theory and relativistic coupled cluster calculations of the shielding constant that should be used to extract the value of μI(209ipts>) and combine it with nuclear magnetic resonance measurements of Bi (NO3 )3 in nitric acid solutions and of the hexafluoridobismuthate(V) BiF6- ion in acetonitrile. The result clearly reveals that μI(209Bi) is much smaller than the tabulated value used previously. Applying the new magnetic moment shifts the theoretical prediction into agreement with experiment and resolves the hyperfine puzzle.

New Nuclear Magnetic Moment of ^{209}Bi: Resolving the Bismuth Hyperfine Puzzle.

Science.gov (United States)

Skripnikov, Leonid V; Schmidt, Stefan; Ullmann, Johannes; Geppert, Christopher; Kraus, Florian; Kresse, Benjamin; Nörtershäuser, Wilfried; Privalov, Alexei F; Scheibe, Benjamin; Shabaev, Vladimir M; Vogel, Michael; Volotka, Andrey V

2018-03-02

A recent measurement of the hyperfine splitting in the ground state of Li-like ^{208}Bi^{80+} has established a "hyperfine puzzle"-the experimental result exhibits a 7σ deviation from the theoretical prediction [J. Ullmann et al., Nat. Commun. 8, 15484 (2017)NCAOBW2041-172310.1038/ncomms15484; J. P. Karr, Nat. Phys. 13, 533 (2017)NPAHAX1745-247310.1038/nphys4159]. We provide evidence that the discrepancy is caused by an inaccurate value of the tabulated nuclear magnetic moment (μ_{I}) of ^{209}Bi. We perform relativistic density functional theory and relativistic coupled cluster calculations of the shielding constant that should be used to extract the value of μ_{I}(^{209}Bi) and combine it with nuclear magnetic resonance measurements of Bi(NO_{3})_{3} in nitric acid solutions and of the hexafluoridobismuthate(V) BiF_{6}^{-} ion in acetonitrile. The result clearly reveals that μ_{I}(^{209}Bi) is much smaller than the tabulated value used previously. Applying the new magnetic moment shifts the theoretical prediction into agreement with experiment and resolves the hyperfine puzzle.

Electron and nuclear spin interactions in the optical spectra of single GaAs quantum dots.

Science.gov (United States)

Gammon, D; Efros, A L; Kennedy, T A; Rosen, M; Katzer, D S; Park, D; Brown, S W; Korenev, V L; Merkulov, I A

2001-05-28

Fine and hyperfine splittings arising from electron, hole, and nuclear spin interactions in the magneto-optical spectra of individual localized excitons are studied. We explain the magnetic field dependence of the energy splitting through competition between Zeeman, exchange, and hyperfine interactions. An unexpectedly small hyperfine contribution to the splitting close to zero applied field is described well by the interplay between fluctuations of the hyperfine field experienced by the nuclear spin and nuclear dipole/dipole interactions.

Nature of the Darwin term and (Zα)4m3/M2 contribution to the Lamb shift for an arbitrary spin of the nucleus

International Nuclear Information System (INIS)

Khriplovich, I.B.; Milstein, A.I.; Sen'kov, R.A.

1997-01-01

The contact Darwin term is demonstrated to be of the same origin as the spin-orbit interaction. The (Zα) 4 m 3 /M 2 correction for the Lamb shift, generated by the Darwin term is found for an arbitrary nonvanishing spin of the nucleus, both half-integer and integer. There is also a contribution of the same nature to the nuclear quadrupole moment

Quantifying the importance of orbital over spin correlations in delta-Pu within density-functional theory

International Nuclear Information System (INIS)

Soderlind, P

2008-01-01

The electronic structure of plutonium is studied within the density-functional theory (DFT) model. Key features of the electronic structure are correctly modeled and bonding, total energy, and electron density of states are all consistent with measure data, although the prediction of magnetism is not consistent with many observations. Here we analyze the contributions to the electronic structure arising from spin polarization, orbital polarization, and spin-orbit interaction. These effects give rise to spin and orbital moments that are of nearly equal magnitude, but anti-parallel, suggesting a magnetic-moment cancellation with a zero total moment. Quantifying the spin versus orbital effects on the bonding, total energy, and electron spectra it becomes clear that the spin polarization is much less important than the orbital correlations. Consequently, a restricted DFT approach with a non-spin polarized electronic structure can produce reasonable equation-of-state and electron spectra for (delta)-Pu when the orbital effects are accounted for. Hence, we present two non-magnetic models. One in which the spin moment is canceled by the orbital moment and another in which the spin moment (and therefore the orbital moment) is restricted to zero

An effect of nuclear electric quadrupole moments in thermonuclear fusion plasmas

Science.gov (United States)

De, B. R.; Srnka, L. J.

1978-01-01

Consideration of the nuclear electric quadrupole terms in the expression for the fusion Coulomb barrier suggests that this electrostatic barrier may be substantially modified from that calculated under the usual plasma assumption that the nuclei are electric monopoles. This effect is a result of the nonspherical potential shape and the spatial quantization of the nuclear spins of the fully stripped ions in the presence of a magnetic field. For monopole-quadrupole fuel cycles like p-B-11, the fusion cross-section may be substantially increased at low energies if the protons are injected at a small angle relative to the confining magnetic field.

Theoretical studies on nuclear spin selective quantum dynamics of non-linear molecules; Theoretische Untersuchung zur Quantendynamik der Kernspinisomere nicht-linearer Molekuele

Energy Technology Data Exchange (ETDEWEB)

Grohmann, Thomas

2012-05-31

In this thesis the wave packet dynamics of nuclear spin isomers of polyatomic molecules after interaction with static and time-dependent magnetic fields and moderate intense nonresonant laser pulses is investigated. In particular, the process of inducing (internal) molecular rotation as well as alignment of molecules by manipulating their rotational or rotational-torsional degrees of freedom is studied. In the first part of the thesis all theoretical concepts for identifying nuclear spin isomers and for describing their quantum dynamics will be discussed. Especially the symmetrization postulate and themolecular symmetry group will be introduced and illustrated for some examples of molecules. These concepts will be extended to the case of identifying nuclear spin isomers in the presence of an external field. In the second part it is shown for nitromethane that magnetic fields are able to induce unidirectional rotations in opposite directions for different nuclear spin isomers of molecules containing methyl groups if the dipolar interaction is included. Additionally, it is demonstrated that different nuclear spin isomers of a chemical compound may show different alignment after the interaction with a moderate intense laser pulse. As shown for the rigid symmetric top propadien and the rigid asymmetric tops ethene and analogues, distinct pairs of nuclear spin isomers show at certain points in time a complementary behavior: while one isomer is showing alignment the partner isomer is showing anti-alignment. Moreover, it is illustrated that not every nuclear spin isomer can be aligned equally efficient. The alignment of non-rigid molecules is considered as well. As an example for a molecule with feasible torsion in the electronic ground state, the alignment of diboron tetrafluoride is investigated. It becomes apparent that not only rotational but also the torsional dynamics of the molecules is nuclear spin selective; different nuclear spin isomers have at distinct points

Force-detected nuclear magnetic resonance: recent advances and future challenges.

Science.gov (United States)

Poggio, M; Degen, C L

2010-08-27

We review recent efforts to detect small numbers of nuclear spins using magnetic resonance force microscopy. Magnetic resonance force microscopy (MRFM) is a scanning probe technique that relies on the mechanical measurement of the weak magnetic force between a microscopic magnet and the magnetic moments in a sample. Spurred by the recent progress in fabricating ultrasensitive force detectors, MRFM has rapidly improved its capability over the last decade. Today it boasts a spin sensitivity that surpasses conventional, inductive nuclear magnetic resonance detectors by about eight orders of magnitude. In this review we touch on the origins of this technique and focus on its recent application to nanoscale nuclear spin ensembles, in particular on the imaging of nanoscale objects with a three-dimensional (3D) spatial resolution better than 10 nm. We consider the experimental advances driving this work and highlight the underlying physical principles and limitations of the method. Finally, we discuss the challenges that must be met in order to advance the technique towards single nuclear spin sensitivity-and perhaps-to 3D microscopy of molecules with atomic resolution.

Protocol for generating multiphoton entangled states from quantum dots in the presence of nuclear spin fluctuations

DEFF Research Database (Denmark)

Denning, Emil Vosmar; Iles-Smith, Jake; McCutcheon, Dara P. S.

2017-01-01

Multiphoton entangled states are a crucial resource for many applications inquantum information science. Semiconductor quantum dots offer a promising route to generate such states by mediating photon-photon correlations via a confinedelectron spin, but dephasing caused by the host nuclear spin...... environment typically limits coherence (and hence entanglement) between photons to the spin T2* time of a few nanoseconds. We propose a protocol for the deterministic generation of multiphoton entangled states that is inherently robust against the dominating slow nuclear spin environment fluctuations, meaning...... that coherence and entanglement is instead limited only by the much longer spin T2 time of microseconds. Unlike previous protocols, the present schemeallows for the generation of very low error probability polarisation encoded three-photon GHZ states and larger entangled states, without the need for spin echo...

Nuclear structure at high-spin and large-deformation

International Nuclear Information System (INIS)

Shimizu, Yoshifumi R.

2000-01-01

Atomic nucleus is a finite quantal system and shows various marvelous features. One of the purposes of the nuclear structure study is to understand such features from a microscopic viewpoint of nuclear many-body problem. Recently, it is becoming possible to explore nuclear states under 'extreme conditions', which are far different from the usual ground states of stable nuclei, and new aspects of such unstable nuclei attract our interests. In this lecture, I would like to discuss the nuclear structure in the limit of rapid rotation, or the extreme states with very large angular momenta, which became accessible by recent advent of large arrays of gamma-ray detecting system; these devices are extremely useful to measure coincident multiple γ-rays following heavy-ion fusion reactions. Including such experimental aspects as how to detect the nuclear rotational states, I review physics of high-spin states starting from the elementary subjects of nuclear structure study. In would like also to discuss the extreme states with very large nuclear deformation, which are easily realized in rapidly rotating nuclei. (author)

Magnetic moments revisited

International Nuclear Information System (INIS)

Towner, I.S.; Khanna, F.C.

1984-01-01

Consideration of core polarization, isobar currents and meson-exchange processes gives a satisfactory understanding of the ground-state magnetic moments in closed-shell-plus (or minus)-one nuclei, A = 3, 15, 17, 39 and 41. Ever since the earliest days of the nuclear shell model the understanding of magnetic moments of nuclear states of supposedly simple configurations, such as doubly closed LS shells +-1 nucleon, has been a challenge for theorists. The experimental moments, which in most cases are known with extraordinary precision, show a small yet significant departure from the single-particle Schmidt values. The departure, however, is difficult to evaluate precisely since, as will be seen, it results from a sensitive cancellation between several competing corrections each of which can be as large as the observed discrepancy. This, then, is the continuing fascination of magnetic moments. In this contribution, we revisit the subjet principally to identify the role played by isobar currents, which are of much concern at this conference. But in so doing we warn quite strongly of the dangers of considering just isobar currents in isolation; equal consideration must be given to competing processes which in this context are the mundane nuclear structure effects, such as core polarization, and the more popular meson-exchange currents

Angle and temperature dependence of the magnetocrystalline anisotropy energy and the microscopic magnetic moments of the ferromagnetic semi-metal CrO{sub 2}; Winkel- und Temperaturabhaengigkeit der magnetokristallinen Anisotropieenergie und der mikroskopischen magnetischen Momente des ferromagnetischen Halbmetalls CrO{sub 2}

Energy Technology Data Exchange (ETDEWEB)

Gold, S.

2005-07-01

The aim of this work was to examine, by use of XMCD-effect and additional measurements with SQUID-magnetometer, spin moments and hysteresis loops, but also to clarify the intrinsic properties like magnetocrystalline anisotropy, magnetic dipole term, and the nearly quenched orbital moment. The XMCD-measurements were done at the Cr L{sub 2,3}- and the O K-edge. The results for CrO{sub 2} show a strong dependence of the orbital, the sum of spin moment and magnetic dipole term, and the magnetocrystalline anisotropy energy from the angle between rutile a- and c-axis. Even more than the complete orbital moment, two separable and different spectral features show strong alterations of the different orbital moments. In a second part of this work the temperature dependence was investigated. The aim was to clarify the origin of the orbital moment, dipole term, and MAE in dependence of the spin moment and compare the results to different theoretical models. The extracted orbital moments and the magnetic dipole term show the same temperature dependence as the spin moment. In the following a dependence of the squared measured spin moment could be found for the MAE. For the first time the magnetic dipole term could be identified as the reason of the magnetocrystalline anisotropy energy. A strong Cr-O hybridisation was found, which shows in a similar structure and temperature dependence of the orbital moments for Cr L{sub 2,3} and the XMCD effect at O-K edge. (orig.)

Determination of nuclear quadrupole moments – An example of the synergy of ab initio calculations and microwave spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Kellö, Vladimir [Department of Physical Chemistry, Comenius University, SK-842 15 Bratislava (Slovakia)

2015-01-22

Highly correlated scalar relativistic calculations of electric field gradients at nuclei in diatomic molecules in combination with accurate nuclear quadrupole coupling constants obtained from microwave spectroscopy are used for determination of nuclear quadrupole moments.

Three types magnetic moment distribution of nonlinear excitations in a Heisenberg helimagnet

Energy Technology Data Exchange (ETDEWEB)

Qi, Jian-Wen [School of Physics, Northwest University, Xi' an 710069 (China); Shaanxi Key Laboratory for Theoretical Physics Frontiers, Xi' an 710069 (China); Li, Zai-Dong [Department of Applied Physics, Hebei University of Technology, Tianjin 300401 (China); Yang, Zhan-Ying, E-mail: zyyang@nwu.edu.cn [School of Physics, Northwest University, Xi' an 710069 (China); Shaanxi Key Laboratory for Theoretical Physics Frontiers, Xi' an 710069 (China); Yang, Wen-Li [Shaanxi Key Laboratory for Theoretical Physics Frontiers, Xi' an 710069 (China); Institute of Modern Physics, Northwest University, Xi' an 710069 (China)

2017-06-15

Highlights: • Three different types of soliton excitations under the spin-wave background are demonstrated in spin chain system. • The magnetic moment distributions corresponding to these solitons are characterized in detail. • The formation mechanisms of those excitations are explained by the magnon density distribution. - Abstract: We study the nonlinear spin dynamics of an anisotropic Heisenberg helimagnet in a fourth-order integrable nonlinear Schrödinger equation. We demonstrate that there are three types of nonlinear spin excitations on a spin-wave background in the Heisenberg helimagnet, notably including anti-dark soliton, W-shaped soliton, and multi-peak soliton. The magnetic moment distribution that corresponds to each of these are characterized in detail. Additionally, the formation mechanism is clarified by the magnon density distribution.

Theoretical status of baryon magnetic moments

Science.gov (United States)

Franklin, Jerrold

1989-05-01

This talk given at the Eighth International Symposium on High-Energy Spin Physics in Minneapolis, Minnesota (September 12-17, 1988), is a short summary of theoretical results for baryon magnetic moments. Results from the static bag model and pion exchange effects are summarized and compared with experimental data. A list of references for various models and properties effecting the baryon magnetic moments is given at the end of the article. (AIP)

Theoretical status of baryon magnetic moments

International Nuclear Information System (INIS)

Franklin, J.

1989-01-01

This talk given at the Eighth International Symposium on High-Energy Spin Physics in Minneapolis, Minnesota (September 12--17, 1988), is a short summary of theoretical results for baryon magnetic moments. Results from the static bag model and pion exchange effects are summarized and compared with experimental data. A list of references for various models and properties effecting the baryon magnetic moments is given at the end of the article

Nuclear spin response studies in inelastic polarized proton scattering

International Nuclear Information System (INIS)

Jones, K.W.

1988-01-01

Spin-flip probabilities S/sub nn/ have been measured for inelastic proton scattering at incident proton energies around 300 MeV from a number of nuclei. At low excitation energies S/sub nn/ is below the free value. For excitation energies above about 30 MeV for momentum transfers between about 0.35 fm/sup /minus/1/ and 0.65 fm/sup / minus/1/ S/sub nn/ exceeds free values significantly. These results suggest that the relative ΔS = 1(ΔS = 0 + ΔS = 1) nuclear spin response approaches about 90% in the region of the enhancement. Comparison of the data with slab response calculations are presented. Decomposition of the measured cross sections into σ(ΔS = 0) and σ(ΔS = 1) permit extraction of nonspin-flip and spin-flip dipole and quadrupole strengths. 29 refs., 11 figs

Probing Nuclear Spin Effects on Electronic Spin Coherence via EPR Measurements of Vanadium(IV) Complexes.

Science.gov (United States)

Graham, Michael J; Krzyaniak, Matthew D; Wasielewski, Michael R; Freedman, Danna E

2017-07-17

Quantum information processing (QIP) has the potential to transform numerous fields from cryptography, to finance, to the simulation of quantum systems. A promising implementation of QIP employs unpaired electronic spins as qubits, the fundamental units of information. Though molecular electronic spins offer many advantages, including chemical tunability and facile addressability, the development of design principles for the synthesis of complexes that exhibit long qubit superposition lifetimes (also known as coherence times, or T 2 ) remains a challenge. As nuclear spins in the local qubit environment are a primary cause of shortened superposition lifetimes, we recently conducted a study which employed a modular spin-free ligand scaffold to place a spin-laden propyl moiety at a series of fixed distances from an S = 1 / 2 vanadium(IV) ion in a series of vanadyl complexes. We found that, within a radius of 4.0(4)-6.6(6) Å from the metal center, nuclei did not contribute to decoherence. To assess the generality of this important design principle and test its efficacy in a different coordination geometry, we synthesized and investigated three vanadium tris(dithiolene) complexes with the same ligand set employed in our previous study: K 2 [V(C 5 H 6 S 4 ) 3 ] (1), K 2 [V(C 7 H 6 S 6 ) 3 ] (2), and K 2 [V(C 9 H 6 S 8 ) 3 ] (3). We specifically interrogated solutions of these complexes in DMF-d 7 /toluene-d 8 with pulsed electron paramagnetic resonance spectroscopy and electron nuclear double resonance spectroscopy and found that the distance dependence present in the previously synthesized vanadyl complexes holds true in this series. We further examined the coherence properties of the series in a different solvent, MeCN-d 3 /toluene-d 8 , and found that an additional property, the charge density of the complex, also affects decoherence across the series. These results highlight a previously unknown design principle for augmenting T 2 and open new pathways for the

Seismic signal simulation and study of underground nuclear sources by moment inversion

International Nuclear Information System (INIS)

Crusem, R.

1986-09-01

Some problems of underground nuclear explosions are examined from the seismological point of view. In the first part a model is developed for mean seismic propagation through the lagoon of Mururoa atoll and for calculation of synthetic seismograms (in intermediate fields: 5 to 20 km) by summation of discrete wave numbers. In the second part this ground model is used with a linear inversion method of seismic moments for estimation of elastic source terms equivalent to the nuclear source. Only the isotrope part is investigated solution stability is increased by using spectral smoothing and a minimal phase hypothesis. Some examples of applications are presented: total energy estimation of a nuclear explosion, simulation of mechanical effects induced by an underground explosion [fr

Temperature dependent spin momentum densities in Ni-Mn-In alloys

International Nuclear Information System (INIS)

Ahuja, B L; Dashora, Alpa; Vadkhiya, L; Heda, N L; Priolkar, K R; Lobo, Nelson; Itou, M; Sakurai, Y; Chakrabarti, Aparna; Singh, Sanjay; Barman, S R

2010-01-01

The spin-dependent electron momentum densities in Ni 2 MnIn and Ni 2 Mn 1.4 In 0.6 shape memory alloy using magnetic Compton scattering with 182.2 keV circularly polarized synchrotron radiation are reported. The magnetic Compton profiles were measured at different temperatures ranging between 10 and 300 K. The profiles have been analyzed mainly in terms of Mn 3d electrons to determine their role in the formation of the total spin moment. We have also computed the spin polarized energy bands, partial and total density of states, Fermi surfaces and spin moments using full potential linearized augmented plane wave and spin polarized relativistic Korringa-Kohn-Rostoker methods. The total spin moments obtained from our magnetic Compton profile data are explained using both the band structure models. The present Compton scattering investigations are also compared with magnetization measurements.

Spinning Eggs and Ballerinas

Science.gov (United States)

Cross, Rod

2013-01-01

Measurements are presented on the rise of a spinning egg. It was found that the spin, the angular momentum and the kinetic energy all decrease as the egg rises, unlike the case of a ballerina who can increase her spin and kinetic energy by reducing her moment of inertia. The observed effects can be explained, in part, in terms of rolling friction…

Measurements of nuclear polarization and nuclear magnetic moment of 170Tm in 170Tm:SrF2 by optical pumping

International Nuclear Information System (INIS)

Shimomura, K.

1988-01-01

Significant nuclear polarization of unstable 170 Tm in Tm 2+ :SrF 2 was for the first time achieved with β-ray radiation detected optical pumping in solids, providing a new powerful method to measure magnetic moments of unstable nuclei. (author)

Excitation energy and angular momentum dependence of the nuclear level densities

International Nuclear Information System (INIS)

Razavi, R.; Kakavand, T.; Behkami, A. N.

2007-01-01

We have investigated the excitation energy (E) dependence of nuclear level density for Bethe formula and constant temperature model. The level density parameter aa nd the back shifted energy from the Bethe formula are obtained by fitting the complete level schemes. Also the level density parameters from the constant temperature model have been determined for several nuclei. we have shown that the microscopic theory provides more precise information on the nuclear level densities. On the other hand, the spin cut-off parameter and effective moment of inertia are determined by studying of the angular momentum (J) dependence of the nuclear level density, and effective moment of inertia is compared with rigid body value.

Nature of the Darwin term and (Zα)4m3/M2 contribution to the Lamb shift for an arbitrary spin of the nucleus

International Nuclear Information System (INIS)

Khriplovich, I.B.; Mil'shtejn, A.I.; Sen'kov, R.A.

1996-01-01

The contact Darwin term is demonstrated to be of the same origin as the spin-orbit interactions. The (Zα) 4 m 3 /M 2 correction to the Lamb shift, generated by the Darwin term, is found for an arbitrary nonvanishing spin of the nucleus, both half-integer and integer. There is also a contribution of the same nature to the nuclear quadrupole moment [ru

Nature of the Darwin term and (Zα)4 m3/M2 contribution to the Lamb shift for an arbitrary spin of the nucleus

International Nuclear Information System (INIS)

Khriplovich, I.B.

1996-01-01

The contact Darwin term is demonstrated to be of the same origin as the spin-orbit interaction. The (Zα) 4 m 3 /M 2 correction to the Lamb shift, generated by the Darwin term, is found for an arbitrary nonvanishing spin of the nucleus, both half-integer and integer. There is also a contribution of the same nature to the nuclear quadrupole moment. (orig.)

Nature of the Darwin term and (Zα)4m3/M2 contribution to the Lamb shift for an arbitrary spin of a nucleus

International Nuclear Information System (INIS)

Khriplovich, I.B.; Milstein, A.I.; Sen'kov, R.A.

1997-01-01

The contact Darwin term is demonstrated to be of the same origin at the spin-orbit interaction. The (Zα) 4 m 3 /M 2 correction for the Lamb shift which is generated by the Darwin term, is found for an arbitrary nonvanishing spin of the nucleus, both half-integer and integer. There is also a contribution of the same nature to the nuclear quadrupole moment

Electrical Initialization of Electron and Nuclear Spins in a Single Quantum Dot at Zero Magnetic Field.

Science.gov (United States)

Cadiz, Fabian; Djeffal, Abdelhak; Lagarde, Delphine; Balocchi, Andrea; Tao, Bingshan; Xu, Bo; Liang, Shiheng; Stoffel, Mathieu; Devaux, Xavier; Jaffres, Henri; George, Jean-Marie; Hehn, Michel; Mangin, Stephane; Carrere, Helene; Marie, Xavier; Amand, Thierry; Han, Xiufeng; Wang, Zhanguo; Urbaszek, Bernhard; Lu, Yuan; Renucci, Pierre

2018-04-11

The emission of circularly polarized light from a single quantum dot relies on the injection of carriers with well-defined spin polarization. Here we demonstrate single dot electroluminescence (EL) with a circular polarization degree up to 35% at zero applied magnetic field. The injection of spin-polarized electrons is achieved by combining ultrathin CoFeB electrodes on top of a spin-LED device with p-type InGaAs quantum dots in the active region. We measure an Overhauser shift of several microelectronvolts at zero magnetic field for the positively charged exciton (trion X + ) EL emission, which changes sign as we reverse the injected electron spin orientation. This is a signature of dynamic polarization of the nuclear spins in the quantum dot induced by the hyperfine interaction with the electrically injected electron spin. This study paves the way for electrical control of nuclear spin polarization in a single quantum dot without any external magnetic field.

The spin-dependent neutralino-nucleus form factor for 127I

International Nuclear Information System (INIS)

Ressell, M.T.

1996-01-01

We present the results of detailed shell model calculations of the spin-dependent elastic form factor for the nucleus 127 I. the calculations were performed in extremely large model spaces which adequately describe the configuration mixing in this nucleus. Good agreement between the calculated and experimental values of the magnetic moment are found. Other nuclear observables are also compared to experiment. The dependence of the form factor upon the model space and effective interaction is discussed

Development of atomic-beam resonance method to measure the nuclear moments of unstable nuclei

Energy Technology Data Exchange (ETDEWEB)

Sugimoto, T., E-mail: sugimoto@ribf.riken.jp [SPring-8 (Japan); Asahi, K. [Tokyo Institute of Technology, Department of Physics (Japan); Kawamura, H.; Murata, J. [Rikkyo University, Department of Physics (Japan); Nagae, D.; Shimada, K. [Tokyo Institute of Technology, Department of Physics (Japan); Ueno, H.; Yoshimi, A. [RIKEN Nishina Center (Japan)

2008-01-15

We have been working on the development of a new technique of atomic-beam resonance method to measure the nuclear moments of unstable nuclei. In the present study, an ion-guiding system to be used as an atomic-beam source have been developed.

Relativistic four-component calculations of indirect nuclear spin-spin couplings with efficient evaluation of the exchange-correlation response kernel

Energy Technology Data Exchange (ETDEWEB)

Křístková, Anežka; Malkin, Vladimir G. [Institute of Inorganic Chemistry, Slovak Academy of Sciences, Dúbravská cesta 9, SK-84536 Bratislava (Slovakia); Komorovsky, Stanislav; Repisky, Michal [Centre for Theoretical and Computational Chemistry, University of Tromsø - The Arctic University of Norway, N-9037 Tromsø (Norway); Malkina, Olga L., E-mail: olga.malkin@savba.sk [Institute of Inorganic Chemistry, Slovak Academy of Sciences, Dúbravská cesta 9, SK-84536 Bratislava (Slovakia); Department of Inorganic Chemistry, Comenius University, Bratislava (Slovakia)

2015-03-21

In this work, we report on the development and implementation of a new scheme for efficient calculation of indirect nuclear spin-spin couplings in the framework of four-component matrix Dirac-Kohn-Sham approach termed matrix Dirac-Kohn-Sham restricted magnetic balance resolution of identity for J and K, which takes advantage of the previous restricted magnetic balance formalism and the density fitting approach for the rapid evaluation of density functional theory exchange-correlation response kernels. The new approach is aimed to speedup the bottleneck in the solution of the coupled perturbed equations: evaluation of the matrix elements of the kernel of the exchange-correlation potential. The performance of the new scheme has been tested on a representative set of indirect nuclear spin-spin couplings. The obtained results have been compared with the corresponding results of the reference method with traditional evaluation of the exchange-correlation kernel, i.e., without employing the fitted electron densities. Overall good agreement between both methods was observed, though the new approach tends to give values by about 4%-5% higher than the reference method. On the average, the solution of the coupled perturbed equations with the new scheme is about 8.5 times faster compared to the reference method.

Relativistic four-component calculations of indirect nuclear spin-spin couplings with efficient evaluation of the exchange-correlation response kernel

International Nuclear Information System (INIS)

Křístková, Anežka; Malkin, Vladimir G.; Komorovsky, Stanislav; Repisky, Michal; Malkina, Olga L.

2015-01-01

In this work, we report on the development and implementation of a new scheme for efficient calculation of indirect nuclear spin-spin couplings in the framework of four-component matrix Dirac-Kohn-Sham approach termed matrix Dirac-Kohn-Sham restricted magnetic balance resolution of identity for J and K, which takes advantage of the previous restricted magnetic balance formalism and the density fitting approach for the rapid evaluation of density functional theory exchange-correlation response kernels. The new approach is aimed to speedup the bottleneck in the solution of the coupled perturbed equations: evaluation of the matrix elements of the kernel of the exchange-correlation potential. The performance of the new scheme has been tested on a representative set of indirect nuclear spin-spin couplings. The obtained results have been compared with the corresponding results of the reference method with traditional evaluation of the exchange-correlation kernel, i.e., without employing the fitted electron densities. Overall good agreement between both methods was observed, though the new approach tends to give values by about 4%-5% higher than the reference method. On the average, the solution of the coupled perturbed equations with the new scheme is about 8.5 times faster compared to the reference method

Band head spin assignment of superdeformed bands in 133Pr using two-parameter formulae

Science.gov (United States)

Sharma, Honey; Mittal, H. M.

2018-03-01

The two-parameter formulae viz. the power index formula, the nuclear softness formula and the VMI model are adopted to accredit the band head spin (I0) of four superdeformed rotational bands in 133Pr. The technique of least square fitting is used to accredit the band head spin for four superdeformed rotational bands in 133Pr. The root mean deviation among the computed transition energies and well-known experimental transition energies are attained by extracting the model parameters from the two-parameter formulae. The determined transition energies are in excellent agreement with the experimental transition energies, whenever exact spins are accredited. The power index formula coincides well with the experimental data and provides minimum root mean deviation. So, the power index formula is more efficient tool than the nuclear softness formula and the VMI model. The deviation of dynamic moment of inertia J(2) against the rotational frequency is also examined.

Superdeformed and high-spin nuclear structure data on the INTERNET

International Nuclear Information System (INIS)

Singh, B.; Firestone, R.B.; Chu, S.Y.F.

1997-01-01

With the advent of the large detector arrays GAMMASPHERE, EUROGAM, and GASP, a wealth of new information about the properties of nuclei at high spin has become available. Superdeformed and high-spin nuclear structure data and associated bibliographic information made available on INTERNET by the Isotopes Project at LBNL are described. The Table of Superdeformed Bands and Fission Isomers on the INTERNET will be updated continuously, and new recent reference lists will be provided approximately every three months. This information will also be published annually in the Table of Isotopes CD-ROM updates. (author)

Magnetic moments of the lowest-lying singly heavy baryons

Science.gov (United States)

Yang, Ghil-Seok; Kim, Hyun-Chul

2018-06-01

A light baryon is viewed as Nc valence quarks bound by meson mean fields in the large Nc limit. In much the same way a singly heavy baryon is regarded as Nc - 1 valence quarks bound by the same mean fields, which makes it possible to use the properties of light baryons to investigate those of the heavy baryons. A heavy quark being regarded as a static color source in the limit of the infinitely heavy quark mass, the magnetic moments of the heavy baryon are determined entirely by the chiral soliton consisting of a light-quark pair. The magnetic moments of the baryon sextet are obtained by using the parameters fixed in the light-baryon sector. In this mean-field approach, the numerical results of the magnetic moments of the baryon sextet with spin 3/2 are just 3/2 larger than those with spin 1/2. The magnetic moments of the bottom baryons are the same as those of the corresponding charmed baryons.

All-optical control of long-lived nuclear spins in rare-earth doped nanoparticles.

Science.gov (United States)

Serrano, D; Karlsson, J; Fossati, A; Ferrier, A; Goldner, P

2018-05-29

Nanoscale systems that coherently couple to light and possess spins offer key capabilities for quantum technologies. However, an outstanding challenge is to preserve properties, and especially optical and spin coherence lifetimes, at the nanoscale. Here, we report optically controlled nuclear spins with long coherence lifetimes (T 2 ) in rare-earth-doped nanoparticles. We detect spins echoes and measure a spin coherence lifetime of 2.9 ± 0.3 ms at 5 K under an external magnetic field of 9 mT, a T 2 value comparable to those obtained in bulk rare-earth crystals. Moreover, we achieve spin T 2 extension using all-optical spin dynamical decoupling and observe high fidelity between excitation and echo phases. Rare-earth-doped nanoparticles are thus the only nano-material in which optically controlled spins with millisecond coherence lifetimes have been reported. These results open the way to providing quantum light-atom-spin interfaces with long storage time within hybrid architectures.

Spin-orbitronics: A new moment for Berry

KAUST Repository

Manchon, Aurelien

2014-01-01

The standard description of spin-orbit torques neglects geometric phase effects. But recent experiments suggest that the Berry curvature gives rise to an anti-damping torque in systems with broken inversion symmetry.

Spin-orbitronics: A new moment for Berry

KAUST Repository

Manchon, Aurelien

2014-04-13

The standard description of spin-orbit torques neglects geometric phase effects. But recent experiments suggest that the Berry curvature gives rise to an anti-damping torque in systems with broken inversion symmetry.

Green function study of a mixed spin-((3)/(2)) and spin-((1)/(2)) Heisenberg ferrimagnetic model

International Nuclear Information System (INIS)

Li Jun; Wei Guozhu; Du An

2004-01-01

The magnetic properties of a mixed spin-((3)/(2)) and spin-((1)/(2)) Heisenberg ferrimagnetic system on a square lattice are investigated theoretically by a multisublattice Green-function technique which takes into account the quantum nature of Heisenberg spins. This model can be relevant for understanding the magnetic behavior of the new class of organometallic materials that exhibit spontaneous magnetic moments at room temperature. We discuss the spontaneous magnetic moments and the finite-temperature phase diagram. We find that there is no compensation point at finite temperature when only the nearest-neighbor interaction and the single-ion anisotropy are included. When the next-nearest-neighbor interaction between spin-((1)/(2)) is taken into account and exceeds a minimum value, a compensation point appears and it is basically unchanged for other values in Hamiltonian fixed. The next-nearest-neighbor interaction between spin-((3)/(2)) has the effect of changing the compensation temperature

Chip-Scale Combinatorial Atomic Navigator (C-SCAN) Low Drift Nuclear Spin Gyroscope

Science.gov (United States)

2018-01-01

suggestions for reducing this burden, to Department of Defense, Washington Headquarters Services, Directorate for Information Operations and Reports (0704...spin-exchange relaxation in a finite magnetic field. We operated the gyroscope using a Ramsey-type interrogation sequence with nuclear spin precession...shift by a factor of 105. Here we use the approach of a Ramsey clock interrogation scheme, where the optical pumping, free evolution, and measurement

Quadrupole moments of low-lying baryons with spin- , spin- , and ...

Indian Academy of Sciences (India)

2013-02-03

Feb 3, 2013 ... boson (GB), successfully explains the 'proton spin crisis' [26], hyperon β decay parame- ters [27], strangeness content in the nucleon [28], and in the N ...... ment of India (SR/S2/HEP-0028/2008) and Department of Atomic Energy, Government of India (2010/37P/48/BRNS/1445). References. [1] R G Sachs ...

Nuclear chemistry research and spectroscopy with radioactive sources. Twenty-second annual progress report, February 1, 1986-January 31, 1987

International Nuclear Information System (INIS)

Fink, R.W.

1986-01-01

The nuclear chemistry group in the School of Chemistry continues investigations of radioactive decay of nuclei far from stability under this DOE contract. These nuclei are produced with heavy ions from the Holifield Heavy Ion Research Facility (HHIRF) and studied on-line with the University Isotope Separator at Oak Ridge (UNISOR). Radioactive decay represents a unique method for the population of low-energy, low-spin structures in nuclei, and new phenomena which do not occur near stability can be explored. Our research interest encompasses three aspects of nuclear structure: (1) nuclear spectroscopy with detailed γγt, e - γt, Xγt, αγt multiparameter coincidence spectrometry; (2) measurements of single γ-ray angular distributions and magnetic moments of mass separated low-temperature oriented nuclei, using the helium dilution refrigerator ''ORIENT'' being installed on-line to the isotope separator; and (3) on-line laser hyperfine structure (hfs) and isotope shift measurements for determination of nuclear quadrupole moments, nuclear spins, and changes in mean nuclear charge radii as a means of revealing systematic shape changes in nuclei. 35 refs., 8 figs., 1 tab

Nuclear spin-spin coupling in a van der Waals-bonded system: xenon dimer.

Science.gov (United States)

Vaara, Juha; Hanni, Matti; Jokisaari, Jukka

2013-03-14

Nuclear spin-spin coupling over van der Waals bond has recently been observed via the frequency shift of solute protons in a solution containing optically hyperpolarized (129)Xe nuclei. We carry out a first-principles computational study of the prototypic van der Waals-bonded xenon dimer, where the spin-spin coupling between two magnetically non-equivalent isotopes, J((129)Xe - (131)Xe), is observable. We use relativistic theory at the four-component Dirac-Hartree-Fock and Dirac-density-functional theory levels using novel completeness-optimized Gaussian basis sets and choosing the functional based on a comparison with correlated ab initio methods at the nonrelativistic level. J-coupling curves are provided at different levels of theory as functions of the internuclear distance in the xenon dimer, demonstrating cross-coupling effects between relativity and electron correlation for this property. Calculations on small Xe clusters are used to estimate the importance of many-atom effects on J((129)Xe - (131)Xe). Possibilities of observing J((129)Xe - (131)Xe) in liquid xenon are critically examined, based on molecular dynamics simulation. A simplistic spherical model is set up for the xenon dimer confined in a cavity, such as in microporous materials. It is shown that the on the average shorter internuclear distance enforced by the confinement increases the magnitude of the coupling as compared to the bulk liquid case, rendering J((129)Xe - (131)Xe) in a cavity a feasible target for experimental investigation.

Nuclear moments and the change of the mean square charge radius of neutron deficient thallium isotopes

International Nuclear Information System (INIS)

Menges, R.; Dinger, U.; Boos, N.; Huber, G.; Schroeder, S.

1992-01-01

The hyperfine structure, isotope and isomeric shifts in the atomic transition 6p 2 P 3/2 -7s 2 S 1/2 , λ=535 nm have been measured for the I=7 and I=2 states of 190,192,194,196 Tl, the I=1/2 and I=9/2 states of 191 Tl and the I=7 isomer of 188 Tl. The thallium isotopes were prepared as fast atomic beams at the GSI on-line mass separator following fusion reactions and - in some cases - subsequent β-decay. The nuclear dipole moments, electric quadrupole moments and the change in the nuclear mean square charge radius are evaluated. The uu-isotopes show an isomeric shift which changes sign between 192 Tl and 194 Tl. (orig.)

Paramagnetic material for quantum information processing: electronic and nuclear spins manipulations in β - Ga2O3: Ti

International Nuclear Information System (INIS)

Mentink-Vigier, Frederic

2011-01-01

Quantum information processing is a major challenge both on fundamental and technological grounds. In this research field, the spin bus concept relies on the use of both the electronic and nuclear spins in which the electron is used as a reading and writing head over the nuclei system which makes the qubit register. The requested material to build a spin bus must have unpaired electrons delocalized over a great number of nuclear spins having long decoherence time. In this work, we studied a spin system composed of titanium (III) interacting with multiple gallium nuclei in gallium oxide. We synthesized and studied the titanium paramagnetic center in gallium oxide single crystals by continuous wave EPR and ENDOR spectroscopy and showed that the electron is delocalized over eight neighbouring gallium nuclei. This study also revealed a strong isotopic effect on the nucleus-nucleus interaction mediated by the electron. When the two nearest gallium nuclei surrounding the titanium are identical (same isotopes) this interaction is one order of magnitude higher than in the case of inequivalent nuclei. This effect can be used in order to reduce the computation time. Finally, the dynamical properties of the spin system have been characterized by pulsed EPR and ENDOR spectroscopy. The electron spin decoherence is driven by instantaneous and spectral diffusion. The nuclear dynamical properties have also been studied in order to determine the order of magnitude of nuclear spin relaxation and decoherence time. (author) [fr

Multiple-Quantum Transitions and Charge-Induced Decoherence of Donor Nuclear Spins in Silicon

Science.gov (United States)

Franke, David P.; Pflüger, Moritz P. D.; Itoh, Kohei M.; Brandt, Martin S.

2017-06-01

We study single- and multiquantum transitions of the nuclear spins of an ensemble of ionized arsenic donors in silicon and find quadrupolar effects on the coherence times, which we link to fluctuating electrical field gradients present after the application of light and bias voltage pulses. To determine the coherence times of superpositions of all orders in the 4-dimensional Hilbert space, we use a phase-cycling technique and find that, when electrical effects were allowed to decay, these times scale as expected for a fieldlike decoherence mechanism such as the interaction with surrounding Si 29 nuclear spins.

Frame-dragging effect in the field of non rotating body due to unit gravimagnetic moment

Science.gov (United States)

Deriglazov, Alexei A.; Ramírez, Walberto Guzmán

2018-04-01

Nonminimal spin-gravity interaction through unit gravimagnetic moment leads to modified Mathisson-Papapetrou-Tulczyjew-Dixon equations with improved behavior in the ultrarelativistic limit. We present exact Hamiltonian of the resulting theory and compute an effective 1/c2-Hamiltonian and leading post-Newtonian corrections to the trajectory and spin. Gravimagnetic moment causes the same precession of spin S as a fictitious rotation of the central body with angular momentum J = M/m S. So the modified equations imply a number of qualitatively new effects, that could be used to test experimentally, whether a rotating body in general relativity has null or unit gravimagnetic moment.

The role of level anti-crossings in nuclear spin hyperpolarization

NARCIS (Netherlands)

Ivanov, Konstantin L.; Pravdivtsev, Andrey N.; Yurkovskaya, Alexandra V.; Vieth, Hans Martin; Kaptein, R

2014-01-01

Nuclear spin hyperpolarization is an important resource for increasing the sensitivity of NMR spectroscopy and MRI. Signal enhancements can be as large as 3-4 orders of magnitude. In hyperpolarization experiments, it is often desirable to transfer the initial polarization to other nuclei of choice,

Moments of the Spin Structure Functions g1p and g1d for 0.05 < Q2 < 3.0 GeV2

Energy Technology Data Exchange (ETDEWEB)

Prok, Yelena; Bosted, Peter; Burkert, Volker; Deur, Alexandre; Dharmawardane, Kahanawita; Dodge, Gail; Griffioen, Keith; Kuhn, Sebastian; Minehart, Ralph; Adams, Gary; Amaryan, Moscov; Amaryan, Moskov; Anghinolfi, Marco; Asryan, G.; Audit, Gerard; Avagyan, Harutyun; Baghdasaryan, Hovhannes; Baillie, Nathan; Ball, J.P.; Ball, Jacques; Baltzell, Nathan; Barrow, Steve; Battaglieri, Marco; Beard, Kevin; Bedlinskiy, Ivan; Bektasoglu, Mehmet; Bellis, Matthew; Benmouna, Nawal; Berman, Barry; Biselli, Angela; Blaszczyk, Lukasz; Boyarinov, Sergey; Bonner, Billy; Bouchigny, Sylvain; Bradford, Robert; Branford, Derek; Briscoe, William; Brooks, William; Bultmann, S.; Bueltmann, Stephen; Butuceanu, Cornel; Calarco, John; Careccia, Sharon; Carman, Daniel; Casey, Liam; Cazes, Antoine; Chen, Shifeng; Cheng, Lu; Cole, Philip; Collins, Patrick; Coltharp, Philip; Cords, Dieter; Corvisiero, Pietro; Crabb, Donald; Crede, Volker; Cummings, John; Dale, Daniel; Dashyan, Natalya; De Masi, Rita; De Vita, Raffaella; De Sanctis, Enzo; Degtiarenko, Pavel; Denizli, Haluk; Dennis, Lawrence; Dhuga, Kalvir; Dickson, Richard; Djalali, Chaden; Doughty, David; Dugger, Michael; Dytman, Steven; Dzyubak, Oleksandr; Egiyan, Hovanes; Egiyan, Kim; Elfassi, Lamiaa; Elouadrhiri, Latifa; Eugenio, Paul; Fatemi, Renee; Fedotov, Gleb; Feldman, Gerald; Fersch, Robert; Feuerbach, Robert; Forest, Tony; Fradi, Ahmed; Funsten, Herbert; Garcon, Michel; Gavalian, Gagik; Gevorgyan, Nerses; Gilfoyle, Gerard; Giovanetti, Kevin; Girod, Francois-Xavier; Goetz, John; Golovach, Evgeny; Gothe, Ralf; Guidal, Michel; Guillo, Matthieu; Guler, Nevzat; Guo, Lei; Gyurjyan, Vardan; Hadjidakis, Cynthia; Hafidi, Kawtar; Hakobyan, Hayk; Hanretty, Charles; Hardie, John; Hassall, Neil; Heddle, David; Hersman, F.; Hicks, Kenneth; Hleiqawi, Ishaq; Holtrop, Maurik; Huertas, Marco; Hyde, Charles; Ilieva, Yordanka; Ireland, David; Ishkhanov, Boris; Isupov, Evgeny; Ito, Mark; Jenkins, David; Jo, Hyon-Suk; Johnstone, John; Joo, Kyungseon; Juengst, Henry; Kalantarians, Narbe; Keith, Christopher; Kellie, James; Khandaker, Mahbubul; Kim, Kui; Kim, Kyungmo; Kim, Wooyoung; Klein, Andreas; Klein, Franz; Klusman, Mike; Kossov, Mikhail; Krahn, Zebulun; Kramer, Laird; Kubarovsky, Valery; Kuhn, Joachim; Kuleshov, Sergey; Kuznetsov, Viacheslav; Lachniet, Jeff; Laget, Jean; Langheinrich, Jorn; Lawrence, Dave; Lima, Ana; Livingston, Kenneth; Lu, Haiyun; Lukashin, K.; MacCormick, Marion; Marchand, Claude; Markov, Nikolai; Mattione, Paul; McAleer, Simeon; McKinnon, Bryan; McNabb, John; Mecking, Bernhard; Mestayer, Mac; Meyer, Curtis; Mibe, Tsutomu; Mikhaylov, Konstantin; Mirazita, Marco; Miskimen, Rory; Mokeev, Viktor; Morand, Ludyvine; Moreno, Brahim; Moriya, Kei; Morrow, Steven; Moteabbed, Maryam; Mueller, James; Munevar Espitia, Edwin; Mutchler, Gordon; Nadel-Turonski, Pawel; Nasseripour, Rakhsha; Niccolai, Silvia; Niculescu, Gabriel; Niculescu, Maria-Ioana; Niczyporuk, Bogdan; Niroula, Megh; Niyazov, Rustam; Nozar, Mina; O' Rielly, Grant; Osipenko, Mikhail; Ostrovidov, Alexander; Park, Kijun; Pasyuk, Evgueni; Paterson, Craig; Anefalos Pereira, S.; Philips, Sasha; Pierce, J.; Pivnyuk, Nikolay; Pocanic, Dinko; Pogorelko, Oleg; Popa, Iulian; Pozdnyakov, Sergey; Preedom, Barry; Price, John; Procureur, Sebastien; Protopopescu, Dan; Qin, Liming; Raue, Brian; Riccardi, Gregory; Ricco, Giovanni; Ripani, Marco; Ritchie, Barry; Rosner, Guenther; Rossi, Patrizia; Rowntree, David; Rubin, Philip; Sabatie, Franck; Salamanca, Julian; Salgado, Carlos; Santoro, Joseph; Sapunenko, Vladimir; Schumacher, Reinhard; Seely, Mikell; Serov, Vladimir; Sharabian, Youri; Sharov, Dmitri; Shaw, Jeffrey; Shvedunov, Nikolay; Skabelin, Alexander; Smith, Elton; Smith, Lee; Sober, Daniel; Sokhan, Daria; Stavinskiy, Aleksey; Stepanyan, Samuel; Stepanyan, Stepan; Stokes, Burnham; Stoler, Paul; Strakovski, Igor; Strauch, Steffen; Suleiman, Riad; Taiuti, Mauro; Tedeschi, David; Tkabladze, Avtandil; Tkachenko, Svyatoslav; Todor, Luminita; Ungaro, Maurizio; V

2009-02-01

The spin structure functions $g_1$ for the proton and the deuteron have been measured over a wide kinematic range in $x$ and \\Q2 using 1.6 and 5.7 GeV longitudinally polarized electrons incident upon polarized NH$_3$ and ND$_3$ targets at Jefferson Lab. Scattered electrons were detected in the CEBAF Large Acceptance Spectrometer, for $0.05 < Q^2 < 5 $\\ GeV$^2$ and $W < 3$ GeV. The first moments of $g_1$ for the proton and deuteron are presented -- both have a negative slope at low \\Q2, as predicted by the extended Gerasimov-Drell-Hearn sum rule. The first result for the generalized forward spin polarizability of the proton $\\gamma_0^p$ is also reported, and shows evidence of scaling above $Q^2$ = 1.5 GeV$^2$. Although the first moments of $g_1$ are consistent with Chiral Perturbation Theory (\\ChPT) calculations up to approximately $Q^2 = 0.06$ GeV$^2$, a significant discrepancy is observed between the $\\gamma_0^p$ data and \\ChPT\\ for $\\gamma_0^p$,even at the lowest \\Q2.

Nuclear spectroscopy of doubly-even130,132Ba

Science.gov (United States)

Gupta, Anuradha; Gupta, Surbhi; Singh, Suram; Bharti, Arun

2018-05-01

A comparative study of some high-spin characteristic nuclear structure properties of doubly-even 130,132Ba nuclei has been made using two microscopic frameworks - CHFB and PSM. The yrast spectra, intrinsic quadrupole moment and deformation systematics of these nuclei have been successfully calculated. Further, the calculated data from both the frameworks is also compared with the available experimental data and a good agreement has been obtained. The present CHFB calculations describes very well the low spin structure of even-even 130,132Ba nuclei whereas PSM calculations provide a qualitative description of the high-spin band structure of doubly-even 130,132Ba nuclei.

On line nuclear orientation: opportunity and challenge

International Nuclear Information System (INIS)

Stone, N.J.

1985-01-01

The development of the on-line nuclear orientation (OLNO) technique is reviewed. The present potential of the technique is discussed in the light of the attainable temperatures, the use of ion implantation and the required isotope flux. Limitations associated with spin-lattice relaxation are considered in some detail and a survey of accessible nuclei is presented. An outline comparison is given between OLNO and other methods for producing orientation of nuclei, for measuring nuclear spins and static moments and for the study of level structure and transition probabilities. The conclusion is drawn that the method in its present form has extensive potential over a wide range of nuclei. Future prospects for in-beam polarisation giving access to nuclei of shorter half lives are referred to briefly. (Auth.)

Comparison of exact-exchange calculations for solids in current-spin-density- and spin-density-functional theory

DEFF Research Database (Denmark)

Sharma, S.; Pittalis, S.; Kurth, S.

2007-01-01

The relative merits of current-spin-density- and spin-density-functional theory are investigated for solids treated within the exact-exchange-only approximation. Spin-orbit splittings and orbital magnetic moments are determined at zero external magnetic field. We find that for magnetic (Fe, Co......, and Ni) and nonmagnetic (Si and Ge) solids, the exact-exchange current-spin-density functional approach does not significantly improve the accuracy of the corresponding spin-density functional results....

Measurement of single electron and nuclear spin states based on optically detected magnetic resonance

Energy Technology Data Exchange (ETDEWEB)

Berman, Gennady P [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Bishop, Alan R [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Chernobrod, Boris M [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Hawley, Marilyn E [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Brown, Geoffrey W [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Tsifrinovich, Vladimir I [Polytechnic University, Brooklyn, NY 11201 (United States)

2006-05-15

A novel approach for measurement of single electron and nuclear spin states is suggested. Our approach is based on optically detected magnetic resonance in a nano-probe located at the apex of an AFM tip. The method provides single electron spin sensitivity with nano-scale spatial resolution.

Measurement of single electron and nuclear spin states based on optically detected magnetic resonance

International Nuclear Information System (INIS)

Berman, Gennady P; Bishop, Alan R; Chernobrod, Boris M; Hawley, Marilyn E; Brown, Geoffrey W; Tsifrinovich, Vladimir I

2006-01-01

A novel approach for measurement of single electron and nuclear spin states is suggested. Our approach is based on optically detected magnetic resonance in a nano-probe located at the apex of an AFM tip. The method provides single electron spin sensitivity with nano-scale spatial resolution

Beyond RPA in nuclear rotation and wobbling motion at high spin

International Nuclear Information System (INIS)

Kaneko, Kazunari

1991-01-01

A quantum mechanical method of the nuclear rotation and the wobbling motion at high spin beyond the small-oscillation approximation is represented within the framework of time-dependent mean-field theory with some constraints. The constraints which determine the choice of the rotating reference frame are considered in the spin-orientation frame and the principal-axis frame. The quantization under such constraints is performed by making use of the Dirac bracket. Then the commutation relations of the angular momentum are derived. (orig.)

Transition quadrupole moments in the superdeformed band of 40Ca

International Nuclear Information System (INIS)

Chiara, C.J.; Ideguchi, E.; Devlin, M.; LaFosse, D.R.; Lerma, F.; Reviol, W.; Ryu, S.K.; Sarantites, D.G.; Baktash, C.; Galindo-Uribarri, A.; Carpenter, M.P.; Janssens, R.V.F.; Lauritsen, T.; Lister, C.J.; Reiter, P.; Seweryniak, D.; Fallon, P.; Goergen, A.; Macchiavelli, A.O.; Rudolph, D.

2003-01-01

The transition quadrupole moments Q t for the superdeformed band in 40 Ca have been determined through thin-target Doppler-shift attenuation analyses. A best-fit value of Q t =1.30±0.05 e b is obtained when a single value is assumed for the entire band. Fitting separate quadrupole moments for in-band transitions decaying from the high-spin states and the presumably admixed low-spin states results in Q t (high)=1.81 -0.26 +0.41 e b and Q t (low)=1.18 -0.05 +0.06 e b, respectively. Q t values extracted for individual transitions in a Doppler-broadened line-shape analysis also indicate smaller Q t values at lower spins. These results are consistent with the interpretation of this band as an eight-particle-eight-hole superdeformed band with a significant admixture of less-collective configurations at low spins

Spin Modes in Nuclei and Nuclear Forces

International Nuclear Information System (INIS)

Suzuki, Toshio; Otsuka, Takaharu

2011-01-01

Spin modes in stable and unstable exotic nuclei are studied and important roles of tensor and three-body forces on nuclear structure are discussed. New shell model Hamiltonians, which have proper tensor components, are shown to explain shell evolutions toward drip-lines and spin properties of both stable and exotic nuclei, for example, Gamow-Teller transitions in 12 C and 14 C and an anomalous M1 transition in 17 C. The importance and the necessity of the repulsive monopole corrections in isospin T = 1 channel to the microscopic two-body interactions are pointed out. The corrections are shown to lead to the proper shell evolutions in neutron-rich isotopes. The three-body force, in particular the Fujita-Miyazawa force induced by Δ excitations, is pointed out to be responsible for the repulsive corrections among the valence neutrons. The important roles of the three-body force on the energies and transitions in exotic oxygen and calcium isotopes are demonstrated.

Moments of inertia in a semiclassical approach

International Nuclear Information System (INIS)

Benchein, K.

1993-01-01

Semiclassical calculations have been performed for 31 nuclei. As a result of preliminary non-fully self-consistent calculations, the moments of inertia in investigated nuclei abd spin degrees of freedom are found

Simulation of spin dynamics to measure electric dipole moments in storage rings

Energy Technology Data Exchange (ETDEWEB)

Rosenthal, Marcel; Lehrach, Andreas [Forschungszentrum Juelich GmbH (Germany). Inst. fuer Kernphysik; Collaboration: JEDI-Collaboration

2013-07-01

CP violation in the baryon sector, which is predicted by the Standard Model of Particle Physics, is too small to explain the matter and antimatter asymmetry in our universe. Permanent Electric Dipole Moments (EDMs) violate both P and T symmetries and are therefore, through the CPT theorem, also CP violating. No direct EDM measurements for protons, deuterons and light nuclei have been performed up to now. The JEDI collaboration at Forschungszentrum Juelich (FZJ) and the BNL-EDM collaboration at Brookhaven National Laboratory (BNL) pursue the goal to measure the EDMs of these particles in dedicated storage rings. Therefore different approaches are studied to reach an ultimate sensitivity of 10{sup -29} e.cm. A first direct measurement of the proton and deuteron EDM at a sensitivity level of 10{sup -24} e.cm will be performed in the existing conventional storage ring at FZJ, the Cooler Synchrotron COSY. Particle tracking simulations to explore the motion-correlated spin dynamics are a crucial part of feasibility studies of the planned storage ring EDM experiments. In a first step, a benchmarking of simulation codes with measurements at the Cooler Synchrotron COSY is performed.

Elementary quantum mechanics of the neutron with an electric dipole moment.

Science.gov (United States)

Baym, Gordon; Beck, D H

2016-07-05

The neutron, in addition to possibly having a permanent electric dipole moment as a consequence of violation of time-reversal invariance, develops an induced electric dipole moment in the presence of an external electric field. We present here a unified nonrelativistic description of these two phenomena, in which the dipole moment operator, [Formula: see text], is not constrained to lie along the spin operator. Although the expectation value of [Formula: see text] in the neutron is less than [Formula: see text] of the neutron radius, [Formula: see text], the expectation value of [Formula: see text] is of order [Formula: see text] We determine the spin motion in external electric and magnetic fields, as used in past and future searches for a permanent dipole moment, and show that the neutron electric polarizability, although entering the neutron energy in an external electric field, does not affect the spin motion. In a simple nonrelativistic model we show that the expectation value of the permanent dipole is, to lowest order, proportional to the product of the time-reversal-violating coupling strength and the electric polarizability of the neutron.

Neutrino magnetic moments and the solar neutrino problem

Energy Technology Data Exchange (ETDEWEB)

Akhmedov, E.Kh. [Washington Univ., Seattle, WA (United States). Inst. for Nuclear Theory]|[Valencia Univ. (Spain). Dept. de Fisica Teorica

1994-08-01

Present status of the neutrino magnetic moment solutions of the solar neutrino problem is reviewed. In particular, we discuss a possibility of reconciling different degrees of suppression and time variation of the signal (or lack of such a variation) observed in different solar neutrino experiments. It is shown that the resonant spin-flavor precession of neutrinos due to the interaction of their transitions magnetic moments with solar magnetic field can account for all the available solar neutrino data. For not too small neutrino mixing angles (sin 2{theta}{sub o} {approx_gt} 0.2 the combined effect of the resonant spin-flavor precession and neutrino oscillations can result in an observable flux of solar {bar {nu}}{sub e}`s.

Neutrino magnetic moments and the solar neutrino problem

International Nuclear Information System (INIS)

Akhmedov, E.Kh.; Valencia Univ.

1994-01-01

Present status of the neutrino magnetic moment solutions of the solar neutrino problem is reviewed. In particular, we discuss a possibility of reconciling different degrees of suppression and time variation of the signal (or lack of such a variation) observed in different solar neutrino experiments. It is shown that the resonant spin-flavor precession of neutrinos due to the interaction of their transitions magnetic moments with solar magnetic field can account for all the available solar neutrino data. For not too small neutrino mixing angles (sin 2θ o approx-gt 0.2 the combined effect of the resonant spin-flavor precession and neutrino oscillations can result in an observable flux of solar bar ν e 's

On the Convergence of the ccJ-pVXZ and pcJ-n Basis Sets in CCSD Calculations of Nuclear Spin-Spin Coupling Constants

DEFF Research Database (Denmark)

Faber, Rasmus; Sauer, Stephan P. A.

2018-01-01

The basis set convergence of nuclear spin-spin coupling constants (SSCC) calculated at the coupled cluster singles and doubles (CCSD) level has been investigated for ten difficult molecules. Eight of the molecules contain fluorine atoms and nine contain double or triple bonds. Results obtained...

High-spin nuclear structure studies with radioactive ion beams

International Nuclear Information System (INIS)

Baktash, C.

1992-01-01

Two important developments in the sixties, namely the advent of heavy-ion accelerators and fabrication of Ge detectors, opened the way for the experimental studies of nuclear properties at high angular momentum. Addition of a new degree of freedom, namely spin, made it possible to observe such fascinating phenomena as occurrences and coexistence of a variety of novel shapes, rise, fall and occasionally rebirth of nuclear collectivity, and disappearance of pairing correlations. Today, with the promise of development of radioactive ion beams (RIB) and construction of the third-generation Ge-detection systems (GAMMASPHERE and EUROBALL), nuclear physicists are poised to explore new and equally fascinating phenomena that have been hitherto inaccessible. With the addition of yet another dimension, namely the isospin, they will be able to observe and verify predictions for exotic shapes as varied as rigid triaxiality, hyperdeformation and triaxial-octupole shapes, or to investigate the T=O pairing correlations. In this paper, the author reviews, separately for neutron-deficient and neutron-rich nuclei, these and a few other new high-spin physics opportunities that may be realized with RIB. Following this discussion, a list of the beam species, intensities and energies that are needed to fulfill these goals is presented. The paper concludes with a description of the experimental techniques and instrumentations that are required for these studies

Transient nutation electron spin resonance spectroscopy on spin-correlated radical pairs: A theoretical analysis on hyperfine-induced nuclear modulations

Science.gov (United States)

Weber, Stefan; Kothe, Gerd; Norris, James R.

1997-04-01

The influence of anisotropic hyperfine interaction on transient nutation electron paramagnetic resonance (EPR) of light-induced spin-correlated radical pairs is studied theoretically using the density operator formalism. Analytical expressions for the time evolution of the transient EPR signal during selective microwave excitation of single transitions are derived for a model system comprised of a weakly coupled radical pair and one hyperfine-coupled nucleus with I=1/2. Zero-quantum electron coherence and single-quantum nuclear coherence are created as a result of the sudden light-induced generation of the radical pair state from a singlet-state precursor. Depending on the relative sizes of the nuclear Zeeman frequency and the secular and pseudo-secular parts of the hyperfine coupling, transitions between levels with different nuclear spin orientations are predicted to modulate the time-dependent EPR signal. These modulations are in addition to the well-known transient nutations and electron zero-quantum precessions. Our calculations provide insight into the mechanism of recent experimental observations of coherent nuclear modulations in the time-resolved EPR signals of doublets and radical pairs. Two distinct mechanisms of the modulations are presented for various microwave magnetic field strengths. The first modulation scheme arises from electron and nuclear coherences initiated by the laser excitation pulse and is "read out" by the weak microwave magnetic field. While the relative modulation depth of these oscillations with respect to the signal intensity is independent of the Rabi frequency, ω1, the frequencies of this coherence phenomenon are modulated by the effective microwave amplitude and determined by the nuclear Zeeman interaction and hyperfine coupling constants as well as the electron-electron spin exchange and dipolar interactions between the two radical pair halves. In a second mechanism the modulations are both created and detected by the microwave

Spin Conference

International Nuclear Information System (INIS)

Anon.

1983-01-01

The 5th International Symposium on High Energy Spin Physics met in September at Brookhaven. The symposium has evolved to include a number of diverse specialities: theory, including parity violations and proposed quantum chromodynamics (QCD) tests with polarized beams; experiment, including the large spin effects discovered in high transverse momentum elastic scattering and hyperon production, dibaryons, and magnetic moments; acceleration and storage of polarized protons and electrons; and development of polarized sources and targets

Nuclear scales

Energy Technology Data Exchange (ETDEWEB)

Friar, J.L.

1998-12-01

Nuclear scales are discussed from the nuclear physics viewpoint. The conventional nuclear potential is characterized as a black box that interpolates nucleon-nucleon (NN) data, while being constrained by the best possible theoretical input. The latter consists of the longer-range parts of the NN force (e.g., OPEP, TPEP, the {pi}-{gamma} force), which can be calculated using chiral perturbation theory and gauged using modern phase-shift analyses. The shorter-range parts of the force are effectively parameterized by moments of the interaction that are independent of the details of the force model, in analogy to chiral perturbation theory. Results of GFMC calculations in light nuclei are interpreted in terms of fundamental scales, which are in good agreement with expectations from chiral effective field theories. Problems with spin-orbit-type observables are noted.

Nuclear scales

International Nuclear Information System (INIS)

Friar, J.L.

1998-01-01

Nuclear scales are discussed from the nuclear physics viewpoint. The conventional nuclear potential is characterized as a black box that interpolates nucleon-nucleon (NN) data, while being constrained by the best possible theoretical input. The latter consists of the longer-range parts of the NN force (e.g., OPEP, TPEP, the π-γ force), which can be calculated using chiral perturbation theory and gauged using modern phase-shift analyses. The shorter-range parts of the force are effectively parameterized by moments of the interaction that are independent of the details of the force model, in analogy to chiral perturbation theory. Results of GFMC calculations in light nuclei are interpreted in terms of fundamental scales, which are in good agreement with expectations from chiral effective field theories. Problems with spin-orbit-type observables are noted

Nuclear collectivity and complex alignment mechanisms in light tungsten and osmium nuclei

International Nuclear Information System (INIS)

Johnson, N.R.

1989-01-01

During the past few years there have been significant advances in our understanding of nuclei excited into states of high angular momentum. The development of large multi-detector arrays for γ-γ coincidence spectroscopy studies has propelled the amount of new experimental information available and this has been complemented by notable advances in the theoretical treatments of high-spin phenomena. To provide yet a more detailed understanding of the structure of these high-spin states and to provide a stringent test of these models, we have resorted to measurements of their dynamic electromagnetic multipole moments which are a direct reflection of the collective aspects of the nuclear wave functions. For the most part, these multipole moments are obtained by lifetime measurements utilizing Doppler-shift techniques. Let me stress that the great value of lifetime measurements is that they provide the transition matrix elements without the necessity to rely on nuclear models. 24 refs., 10 figs

Spin-orbit interaction driven dimerization in one dimensional frustrated magnets

Science.gov (United States)

Zhang, Shang-Shun; Batista, Cristian D.

Spin nematic ordering has been proposed to emerge near the saturation of field of a class of frustrated magnets. The experimental observation of this novel phase is challenging for the traditional experimental probes. Nematic spin ordering is expected to induce a local quadrupolar electric moment via the spin-orbit coupling. However, a finite spin-orbit interaction explicitly breaks the U(1) symmetry of global spin rotations down to Z2, which renders the traditional nematic order no longer well-defined. In this work we investigate the relevant effect of spin-orbit interaction on the 1D frustrated J1 -J2 model. The real and the imaginary parts of the nematic order parameter belong to different representations of the discrete symmetry group of the new Hamiltonian. We demonstrate that spin-orbit coupling stabilizes the real component and simultaneously induces bond dimerization in most of the phase diagram. Such a bond dimerization can be observed with X-rays or nuclear magnetic resonance. In addition, an incommensurate bond-density wave (ICBDW) appears for smaller values of J2 / |J1 | . The experimental fingerprint of the ICBDW is a double-horn shape of the the NMR line. These conclusions can shed light on the experimental search of this novel phase.

Solid-state nuclear-spin quantum computer based on magnetic resonance force microscopy

International Nuclear Information System (INIS)

Berman, G. P.; Doolen, G. D.; Hammel, P. C.; Tsifrinovich, V. I.

2000-01-01

We propose a nuclear-spin quantum computer based on magnetic resonance force microscopy (MRFM). It is shown that an MRFM single-electron spin measurement provides three essential requirements for quantum computation in solids: (a) preparation of the ground state, (b) one- and two-qubit quantum logic gates, and (c) a measurement of the final state. The proposed quantum computer can operate at temperatures up to 1 K. (c) 2000 The American Physical Society

Nuclear spin optical rotation and Faraday effect in gaseous and liquid water.

Science.gov (United States)

Pennanen, Teemu S; Ikäläinen, Suvi; Lantto, Perttu; Vaara, Juha

2012-05-14

Nuclear spin optical rotation (NSOR) of linearly polarized light, due to the nuclear spins through the Faraday effect, provides a novel probe of molecular structure and could pave the way to optical detection of nuclear magnetization. We determine computationally the effects of the liquid medium on NSOR and the Verdet constant of Faraday rotation (arising from an external magnetic field) in water, using the recently developed theory applied on a first-principles molecular dynamics trajectory. The gas-to-liquid shifts of the relevant antisymmetric polarizability and, hence, NSOR magnitude are found to be -14% and -29% for (1)H and (17)O nuclei, respectively. On the other hand, medium effects both enhance the local electric field in water and, via bulk magnetization, the local magnetic field. Together these two effects partially cancel the solvation influence on the single-molecular property. We find a good agreement for the hydrogen NSOR with a recent pioneering experiment on H(2)O(l).

Nuclear scissors modes and hidden angular momenta

Energy Technology Data Exchange (ETDEWEB)

Balbutsev, E. B., E-mail: balbuts@theor.jinr.ru; Molodtsova, I. V. [Joint Institute for Nuclear Research (Russian Federation); Schuck, P. [Université Paris-Sud, Institut de Physique Nucléaire, IN2P3–CNRS (France)

2017-01-15

The coupled dynamics of low-lying modes and various giant resonances are studied with the help of the Wigner Function Moments method generalized to take into account spin degrees of freedom and pair correlations simultaneously. The method is based on Time-Dependent Hartree–Fock–Bogoliubov equations. The model of the harmonic oscillator including spin–orbit potential plus quadrupole–quadrupole and spin–spin interactions is considered. New low-lying spin-dependent modes are analyzed. Special attention is paid to the scissors modes. A new source of nuclear magnetism, connected with counter-rotation of spins up and down around the symmetry axis (hidden angular momenta), is discovered. Its inclusion into the theory allows one to improve substantially the agreement with experimental data in the description of energies and transition probabilities of scissors modes.

Increasing Spin Coherence in Nanodiamond via Dynamic Nuclear Polarization

Science.gov (United States)

Gaebel, Torsten; Rej, Ewa; Boele, Thomas; Waddington, David; Reilly, David

Nanodiamonds are of interest for quantum information technology, as metrological sensors, and more recently as a probe of biological environments. Here we present results examining how intrinsic defects can be used for dynamic nuclear polarization that leads to a dramatic increase in both T1 and T2 for 13C spins in nanodiamond. Mechanisms to explain this enhancement are discussed.

Boundary layer stability on a yawed spinning body of revolution and its effect on the magnus force and moment

Science.gov (United States)

Jacobson, I. D.; Morton, J. B.

1972-01-01

The parameters are established which are important to the stability of a boundary layer flow over a yawed spinning cylinder in a uniform stream. It is shown that transition occurs asymmetrically in general and this asymmetry can be important for the prediction of aerodynamic forces and moments (e.g., the Magnus effect). Instability of the steady-state boundary layer flow is determined using small disturbance theory. Although the approach is strictly valid only for the calculation of the conditions for stability in the small, experimental data indicate that in many problems, it provides a good estimate for the transition to turbulence.

Novel spin effects in quantum chromodynamics

International Nuclear Information System (INIS)

Brodsky, S.J.

1993-02-01

This report discusses a number of interesting hadronic spin effects which test fundamental features of perturbative and non-perturbative QCD. These include constraints on the shape and normalization of the polarized quark and gluon structure functions of the proton; the principle of hadron helicity retention in high x F inclusive reactions; predictions based on total hadron helicity conservation in high momentum transfer exclusive reactions; the dependence of nuclear structure functions and shadowing on virtual photon polarization; and general constraints on the magnetic moment of hadrons. I also will discuss the implications of several measurements which are in striking conflict with leading-twist perturbative QCD predictions, such as the extraordinarily large spin correlation A NN observed in large angle proton-proton scattering, the anomalously large ρπ branching ratio of the J/ψ, and the rapidly changing polarization dependence of both J/ψ and continuum lepton pair hadroproduction observed at large x F

Dynamical spin accumulation in large-spin magnetic molecules

Science.gov (United States)

Płomińska, Anna; Weymann, Ireneusz; Misiorny, Maciej

2018-01-01

The frequency-dependent transport through a nanodevice containing a large-spin magnetic molecule is studied theoretically in the Kondo regime. Specifically, the effect of magnetic anisotropy on dynamical spin accumulation is of primary interest. Such accumulation arises due to finite components of frequency-dependent conductance that are off diagonal in spin. Here, employing the Kubo formalism and the numerical renormalization group method, we demonstrate that the dynamical transport properties strongly depend on the relative orientation of spin moments in electrodes of the device, as well as on intrinsic parameters of the molecule. In particular, the effect of dynamical spin accumulation is found to be greatly affected by the type of magnetic anisotropy exhibited by the molecule, and it develops for frequencies corresponding to the Kondo temperature. For the parallel magnetic configuration of the device, the presence of dynamical spin accumulation is conditioned by the interplay of ferromagnetic-lead-induced exchange field and the Kondo correlations.

High-spin nuclear target of 178m2Hf: creation and nuclear reaction studies

International Nuclear Information System (INIS)

Oganessyan, Yu.Ts.; Karamyan, S.A.; Gangrskij, Yu.P.

1993-01-01

A long-lived (31 years) four-quasiparticle isomer 178m 2 Hf(I,K π =16,16 + ) was produced in microweight quantities using the nuclear reaction 176 Yb( 4 He, 2n). Methods of precision chemistry and mass-separation for the purification of the produced Hf material have been developed. Thin targets of isomeric hafnium-178 on carbon backings were prepared and used in experiments on a neutron, proton and deuteron beams. First results on nuclear reactions on a high-spin exotic target were obtained. Experiments on electromagnetic interactions of the isomeric hafnium using methods of the collinear laser spectroscopy as well as of the nuclear orientation of hafnium implanted into a crystalline media were started. 11 refs.; 11 figs.; 2 tabs

Electric and magnetic dipole moments of the neutron

International Nuclear Information System (INIS)

Ramsey, N.F.

1977-01-01

Experiments to measure the electric and magnetic dipole moments of the neutron are described. The apparatus used in this experiment is one to measure with high precision the precessional frequency of the neutron spin in a weak magnetic field with a neutron beam magnetic resonance apparatus similar to that used for measuring the magnetic moment of the neutron. Results of the measurement are presented. 52 references

Uncertainties for seismic moment tensors and applications to nuclear explosions, volcanic events, and earthquakes

Science.gov (United States)

Tape, C.; Alvizuri, C. R.; Silwal, V.; Tape, W.

2017-12-01

When considered as a point source, a seismic source can be characterized in terms of its origin time, hypocenter, moment tensor, and source time function. The seismologist's task is to estimate these parameters--and their uncertainties--from three-component ground motion recorded at irregularly spaced stations. We will focus on one portion of this problem: the estimation of the moment tensor and its uncertainties. With magnitude estimated separately, we are left with five parameters describing the normalized moment tensor. A lune of normalized eigenvalue triples can be used to visualize the two parameters (lune longitude and lune latitude) describing the source type, while the conventional strike, dip, and rake angles can be used to characterize the orientation. Slight modifications of these five parameters lead to a uniform parameterization of moment tensors--uniform in the sense that equal volumes in the coordinate domain of the parameterization correspond to equal volumes of moment tensors. For a moment tensor m that we have inferred from seismic data for an earthquake, we define P(V) to be the probability that the true moment tensor for the earthquake lies in the neighborhood of m that has fractional volume V. The average value of P(V) is then a measure of our confidence in our inference of m. The calculation of P(V) requires knowing both the probability P(w) and the fractional volume V(w) of the set of moment tensors within a given angular radius w of m. We apply this approach to several different data sets, including nuclear explosions from the Nevada Test Site, volcanic events from Uturuncu (Bolivia), and earthquakes. Several challenges remain: choosing an appropriate misfit function, handling time shifts between data and synthetic waveforms, and extending the uncertainty estimation to include more source parameters (e.g., hypocenter and source time function).

Dynamic-angle spinning and double rotation of quadrupolar nuclei

International Nuclear Information System (INIS)

Mueller, K.T.; California Univ., Berkeley, CA

1991-07-01

Nuclear magnetic resonance (NMR) spectroscopy of quadrupolar nuclei is complicated by the coupling of the electric quadrupole moment of the nucleus to local variations in the electric field. The quadrupolar interaction is a useful source of information about local molecular structure in solids, but it tends to broaden resonance lines causing crowding and overlap in NMR spectra. Magic- angle spinning, which is routinely used to produce high resolution spectra of spin-1/2 nuclei like carbon-13 and silicon-29, is incapable of fully narrowing resonances from quadrupolar nuclei when anisotropic second-order quadrupolar interactions are present. Two new sample-spinning techniques are introduced here that completely average the second-order quadrupolar coupling. Narrow resonance lines are obtained and individual resonances from distinct nuclear sites are identified. In dynamic-angle spinning (DAS) a rotor containing a powdered sample is reoriented between discrete angles with respect to high magnetic field. Evolution under anisotropic interactions at the different angles cancels, leaving only the isotropic evolution of the spin system. In the second technique, double rotation (DOR), a small rotor spins within a larger rotor so that the sample traces out a complicated trajectory in space. The relative orientation of the rotors and the orientation of the larger rotor within the magnetic field are selected to average both first- and second-order anisotropic broadening. The theory of quadrupolar interactions, coherent averaging theory, and motional narrowing by sample reorientation are reviewed with emphasis on the chemical shift anisotropy and second-order quadrupolar interactions experienced by half-odd integer spin quadrupolar nuclei. The DAS and DOR techniques are introduced and illustrated with application to common quadrupolar systems such as sodium-23 and oxygen-17 nuclei in solids

Dynamic-angle spinning and double rotation of quadrupolar nuclei

Energy Technology Data Exchange (ETDEWEB)

Mueller, K.T. (Lawrence Berkeley Lab., CA (United States) California Univ., Berkeley, CA (United States). Dept. of Chemistry)

1991-07-01

Nuclear magnetic resonance (NMR) spectroscopy of quadrupolar nuclei is complicated by the coupling of the electric quadrupole moment of the nucleus to local variations in the electric field. The quadrupolar interaction is a useful source of information about local molecular structure in solids, but it tends to broaden resonance lines causing crowding and overlap in NMR spectra. Magic- angle spinning, which is routinely used to produce high resolution spectra of spin-{1/2} nuclei like carbon-13 and silicon-29, is incapable of fully narrowing resonances from quadrupolar nuclei when anisotropic second-order quadrupolar interactions are present. Two new sample-spinning techniques are introduced here that completely average the second-order quadrupolar coupling. Narrow resonance lines are obtained and individual resonances from distinct nuclear sites are identified. In dynamic-angle spinning (DAS) a rotor containing a powdered sample is reoriented between discrete angles with respect to high magnetic field. Evolution under anisotropic interactions at the different angles cancels, leaving only the isotropic evolution of the spin system. In the second technique, double rotation (DOR), a small rotor spins within a larger rotor so that the sample traces out a complicated trajectory in space. The relative orientation of the rotors and the orientation of the larger rotor within the magnetic field are selected to average both first- and second-order anisotropic broadening. The theory of quadrupolar interactions, coherent averaging theory, and motional narrowing by sample reorientation are reviewed with emphasis on the chemical shift anisotropy and second-order quadrupolar interactions experienced by half-odd integer spin quadrupolar nuclei. The DAS and DOR techniques are introduced and illustrated with application to common quadrupolar systems such as sodium-23 and oxygen-17 nuclei in solids.

{beta}-Ray angular distribution from purely nuclear spin aligned {sup 20}F

Energy Technology Data Exchange (ETDEWEB)

Nagatomo, T., E-mail: nagatomo@riken.jp [RIKEN Nishina Center (Japan); Matsuta, K. [Osaka University (Japan); Minamisono, K. [NSCL/MSU (United States); Sumikama, T. [Tokyo University of Science (Japan); Mihara, M. [Osaka University (Japan); Ozawa, A.; Tagishi, Y. [University of Tsukuba (Japan); Ogura, M.; Matsumiya, R.; Fukuda, M. [Osaka University (Japan); Yamaguchi, M.; Yasuno, T.; Ohta, H.; Hashizume, Y. [University of Tsukuba (Japan); Fujiwara, H. [Osaka University (Japan); Chiba, A. [University of Tsukuba (Japan); Minamisono, T. [Fukui University of Technology (Japan)

2007-11-15

The alignment correlation term in the {beta}-ray angular distribution from purely nuclear spin aligned {sup 20}F has been measured to test the G-parity conservation law which is one of the fundamental symmetries in the weak nucleon current. We utilized the hyperfine interaction of {sup 20}F in an MgF{sub 2} single crystal and successfully created the pure alignment from the polarization by means of the spin manipulation technique based on the {beta}-NMR method.

Cooper pairs' magnetic moment in MCFL color superconductivity

International Nuclear Information System (INIS)

Feng Bo; Ferrer, Efrain J.; Incera, Vivian de la

2011-01-01

We investigate the effect of the alignment of the magnetic moments of Cooper pairs of charged quarks that form at high density in three-flavor quark matter. The high-density phase of this matter in the presence of a magnetic field is known to be the Magnetic Color-Flavor-Locked (MCFL) phase of color superconductivity. We derive the Fierz identities of the theory and show how the explicit breaking of the rotational symmetry by the uniform magnetic field opens new channels of interactions and allows the formation of a new diquark condensate. The new order parameter is a spin-1 condensate proportional to the component in the field direction of the average magnetic moment of the pairs of charged quarks. The magnitude of the spin-1 condensate becomes comparable to the larger of the two scalar gaps in the region of large fields. The existence of the spin-1 condensate is unavoidable, as in the presence of a magnetic field there is no solution of the gap equations with nonzero scalar gaps and zero magnetic moment condensate. This is consistent with the fact that the extra condensate does not break any symmetry that has not already been broken by the known MCFL gaps. The spin-1 condensate enhances the condensation energy of pairs formed by charged quarks and the magnetization of the system. We discuss the possible consequences of the new order parameter on the issue of the chromomagnetic instability that appears in color superconductivity at moderate density.

Collinear Laser Spectroscopy of Potassium Nuclear Charge Radii beyond N = 28

CERN Document Server

AUTHOR|(CDS)2078903; Jochim, Selim

Nuclear ground-state properties, such as spin, charge radius, and magnetic dipole and electric quadrupole moments are important quantities to describe the nucleus. The comparison of experimental data to shell-model calculations gives insight in the underlying nuclear structure and composition of ground-state wave functions. Spins and charge radii can also be used to test the predictions of state-of-the-art microscopic models. This work contributes to these studies providing new measurements in the region of the nuclear chart around the magic proton number Z = 20. The data have been obtained at the collinear laser spectroscopy setup COLLAPS located at the radioactive-ion-beam facility ISOLDE at CERN. Using bunched-beam laser spectroscopy hyperne structure spectra of the potassium isotopes with mass number A = 48 51 could be recorded for the first time. Ground-state spins and isotope shifts could be deduced for 4851K contributing to the evolution of the d3=2 orbital beyond the shell closure at the magi...

Restricted magnetically balanced basis applied for relativistic calculations of indirect nuclear spin-spin coupling tensors in the matrix Dirac-Kohn-Sham framework

International Nuclear Information System (INIS)

Repisky, Michal; Komorovsky, Stanislav; Malkina, Olga L.; Malkin, Vladimir G.

2009-01-01

The relativistic four-component density functional approach based on the use of restricted magnetically balanced basis (mDKS-RMB), applied recently for calculations of NMR shielding, was extended for calculations of NMR indirect nuclear spin-spin coupling constants. The unperturbed equations are solved with the use of a restricted kinetically balanced basis set for the small component while to solve the second-order coupled perturbed DKS equations a restricted magnetically balanced basis set for the small component was applied. Benchmark relativistic calculations have been carried out for the X-H and H-H spin-spin coupling constants in the XH 4 series (X = C, Si, Ge, Sn and Pb). The method provides an attractive alternative to existing approximate two-component methods with transformed Hamiltonians for relativistic calculations of spin-spin coupling constants of heavy-atom systems. In particular, no picture-change effects arise in our method for property calculations

The role of spin-orbit potential in nuclear prolate-shape dominance

Energy Technology Data Exchange (ETDEWEB)

Takahara, Satoshi, E-mail: staka@ks.kyorin-u.ac.jp [Kyorin University, School of Medicine, Mitaka, Tokyo 181-8611 (Japan); Onishi, Naoki [University of Tokyo (Japan); University of Yamanashi (Japan); Shimizu, Yoshifumi R. [Department of Physics, Graduate School of Science, Kyushu University, Fukuoka 812-8581 (Japan); Tajima, Naoki [Department of Applied Physics, University of Fukui, 3-9-1 Bunkyo, Fukui 910-8507 (Japan)

2011-08-26

It is confirmed, in terms of the Woods-Saxon-Strutinsky method, that the spin-orbit potential plays a decisive role in the predominance of prolate deformation, which has been a long standing problem in nuclear physics. It is originated from the combined effects of the spin-orbit coupling and the diffused surface of the potential, in agreement with the previous work based on a more schematic Nilsson-Strutinsky method. The degree of prolate-shape dominance exhibits an oscillatory behavior with respect to the strength of spin-orbit potential and, the prolate-shape dominance is realized at the proper strength of the spin-orbit potential together with the standard surface diffuseness; this oscillatory behavior disappears in case of small diffuseness corresponding to ellipsoidal cavity. The calculated energy differences between oblate and prolate minima in this Letter are consistent with those of our extensive self-consistent calculations of the Hartree-Fock + BCS method with the Skyrme interaction.

The role of spin-orbit potential in nuclear prolate-shape dominance

International Nuclear Information System (INIS)

Takahara, Satoshi; Onishi, Naoki; Shimizu, Yoshifumi R.; Tajima, Naoki

2011-01-01

It is confirmed, in terms of the Woods-Saxon-Strutinsky method, that the spin-orbit potential plays a decisive role in the predominance of prolate deformation, which has been a long standing problem in nuclear physics. It is originated from the combined effects of the spin-orbit coupling and the diffused surface of the potential, in agreement with the previous work based on a more schematic Nilsson-Strutinsky method. The degree of prolate-shape dominance exhibits an oscillatory behavior with respect to the strength of spin-orbit potential and, the prolate-shape dominance is realized at the proper strength of the spin-orbit potential together with the standard surface diffuseness; this oscillatory behavior disappears in case of small diffuseness corresponding to ellipsoidal cavity. The calculated energy differences between oblate and prolate minima in this Letter are consistent with those of our extensive self-consistent calculations of the Hartree-Fock + BCS method with the Skyrme interaction.

Zn and Ni substitutional effects on spin fluctuations in YBa sub 2 Cu sub 3 O sub 7 by sup 6 sup 3 sup , sup 6 sup 5 Cu NQR

CERN Document Server

Han, K S; Mean, B J; Lee, K H; Seo, S W; Lee, M H; Lee, W C

2000-01-01

We have prepared Zn- and Ni-substituted YBa sub 2 Cu sub 3 O sub 7 (YBa sub 2 Cu sub 3 sub - sub x M sub x O sub 7 , M=Zn or Ni, x=0.00 approx 0.09) and performed sup 6 sup 3 sup , sup 6 sup 5 Cu nuclear quadrupole resonance (NQR) measurements for the plane site at 300 and 100 K. Substitutional effects on the relaxation rates are markedly different. Both the spin-lattice and the spin-spin relaxation rates decrease for Zn-doped YBCO. However, those increase for Ni-doped YBCO. This contrast in local electronic dynamics provides clear microscopic evidence that Zn forms no local moment while Ni develops a local moment. Consequently, the antiferromagnetic spin fluctuation is suppressed by Zn doping whereas it is preserved by Ni doping. This is also confirmed by the ratio of the sup 6 sup 3 sup , sup 6 sup 5 Cu spin-lattice relaxation rates for the plane coppers.

Applications of computed nuclear structure functions to inclusive scattering, R-ratios and their moments

International Nuclear Information System (INIS)

Rinat, A.S.

2000-01-01

We discuss applications of previously computed nuclear structure functions (SF) to inclusive cross sections, compare predictions with recent CEBAF data and perform two scaling tests. We mention that the large Q 2 plateau of scaling functions may only in part be due to the asymptotic limit of SF, which prevents the extraction of the nucleon momentum distribution in a model- independent way. We show that there may be sizable discrepancies between computed and semi-heuristic estimates of SF ratios. We compute ratios of moments of nuclear SF and show these to be in reasonable agreement with data. We speculate that an effective theory may underly the model for the nuclear SF, which produces overall agreement with several observables. (author)

Measurement of the Q^{2} Dependence of the Deuteron Spin Structure Function g_{1} and its Moments at Low Q^{2} with CLAS.

Science.gov (United States)

Adhikari, K P; Deur, A; El Fassi, L; Kang, H; Kuhn, S E; Ripani, M; Slifer, K; Zheng, X; Adhikari, S; Akbar, Z; Amaryan, M J; Avakian, H; Ball, J; Balossino, I; Barion, L; Battaglieri, M; Bedlinskiy, I; Biselli, A S; Bosted, P; Briscoe, W J; Brock, J; Bültmann, S; Burkert, V D; Thanh Cao, F; Carlin, C; Carman, D S; Celentano, A; Charles, G; Chen, J-P; Chetry, T; Choi, S; Ciullo, G; Clark, L; Cole, P L; Contalbrigo, M; Crede, V; D'Angelo, A; Dashyan, N; De Vita, R; De Sanctis, E; Defurne, M; Djalali, C; Dodge, G E; Drozdov, V; Dupre, R; Egiyan, H; El Alaoui, A; Elouadrhiri, L; Eugenio, P; Fedotov, G; Filippi, A; Ghandilyan, Y; Gilfoyle, G P; Golovatch, E; Gothe, R W; Griffioen, K A; Guidal, M; Guler, N; Guo, L; Hafidi, K; Hakobyan, H; Hanretty, C; Harrison, N; Hattawy, M; Heddle, D; Hicks, K; Holtrop, M; Hyde, C E; Ilieva, Y; Ireland, D G; Isupov, E L; Jenkins, D; Jo, H S; Johnston, S C; Joo, K; Joosten, S; Kabir, M L; Keith, C D; Keller, D; Khachatryan, G; Khachatryan, M; Khandaker, M; Kim, W; Klein, A; Klein, F J; Konczykowski, P; Kovacs, K; Kubarovsky, V; Lanza, L; Lenisa, P; Livingston, K; Long, E; MacGregor, I J D; Markov, N; Mayer, M; McKinnon, B; Meekins, D G; Meyer, C A; Mineeva, T; Mirazita, M; Mokeev, V; Movsisyan, A; Munoz Camacho, C; Nadel-Turonski, P; Niculescu, G; Niccolai, S; Osipenko, M; Ostrovidov, A I; Paolone, M; Pappalardo, L; Paremuzyan, R; Park, K; Pasyuk, E; Payette, D; Phelps, W; Phillips, S K; Pierce, J; Pogorelko, O; Poudel, J; Price, J W; Prok, Y; Protopopescu, D; Raue, B A; Rizzo, A; Rosner, G; Rossi, P; Sabatié, F; Salgado, C; Schumacher, R A; Sharabian, Y G; Shigeyuki, T; Simonyan, A; Skorodumina, Iu; Smith, G D; Sparveris, N; Sokhan, D; Stepanyan, S; Strakovsky, I I; Strauch, S; Sulkosky, V; Taiuti, M; Tan, J A; Ungaro, M; Voutier, E; Wei, X; Weinstein, L B; Zhang, J; Zhao, Z W

2018-02-09

We measured the g_{1} spin structure function of the deuteron at low Q^{2}, where QCD can be approximated with chiral perturbation theory (χPT). The data cover the resonance region, up to an invariant mass of W≈1.9  GeV. The generalized Gerasimov-Drell-Hearn sum, the moment Γ_{1}^{d} and the spin polarizability γ_{0}^{d} are precisely determined down to a minimum Q^{2} of 0.02  GeV^{2} for the first time, about 2.5 times lower than that of previous data. We compare them to several χPT calculations and models. These results are the first in a program of benchmark measurements of polarization observables in the χPT domain.

Collective properties and shapes of nuclei at very high spins

International Nuclear Information System (INIS)

Johnson, N.R.

1991-01-01

A topic which has been of major interest to us for some years now involves the evolution of nuclear collectivity at high rotational frequencies and the accompanying changes in the shapes of nuclei in these extreme conditions. We carry out these studies by determining the dynamic electromagnetic multipole moments which are a reflection of the collective aspects of the nuclear wave functions. The most direct way to get these multipole moments is by measurements of excited-state lifetimes which provide the transition matrix elements in a fairly straightforward fashion. Although the primary emphasis of this paper is on the collectivity of the high-spin states in 160 Yb and 164 Yb, it is important to review briefly some work we began about ten years ago lifetime studies of moderately high spins in nuclei near N=90 using the recoil-distance (RD) method. These nuclei are just at the onset of permanent deformation and are known to be very soft with respect to deformation changes. This softness is clearly illustrated in contour diagrams of their potential-energy surfaces. For example, the potential energy surface of 160 Yb reveals that the minimum in the potential occurs around var-epsilon ∼ 0.2 and that it is very shallow in the γ degree of freedom. Because of their γ softness, we have studied several nuclei near N=90 to assess to what extent the polarization effects induced by rotation alignment of high-j quasiparticles affect their collectivity

Giant titanium electron wave function in gallium oxide: A potential electron-nuclear spin system for quantum information processing

Science.gov (United States)

Mentink-Vigier, Frédéric; Binet, Laurent; Vignoles, Gerard; Gourier, Didier; Vezin, Hervé

2010-11-01

The hyperfine interactions of the unpaired electron with eight surrounding G69a and G71a nuclei in Ti-doped β-Ga2O3 were analyzed by electron paramagnetic resonance (EPR) and electron-nuclear double resonance (ENDOR) spectroscopies. They are dominated by strong isotropic hyperfine couplings due to a direct Fermi contact interaction with Ga nuclei in octahedral sites of rutile-type chains oriented along b axis, revealing a large anisotropic spatial extension of the electron wave function. Titanium in β-Ga2O3 is thus best described as a diffuse (Ti4+-e-) pair rather than as a localized Ti3+ . Both electron and G69a nuclear spin Rabi oscillations could be observed by pulsed EPR and pulsed ENDOR, respectively. The electron spin decoherence time is about 1μs (at 4 K) and an upper bound of 520μs (at 8 K) is estimated for the nuclear decoherence time. Thus, β-Ga2O3:Ti appears to be a potential spin-bus system for quantum information processing with a large nuclear spin quantum register.

Development of a 3He nuclear spin flip system on an in-situ SEOP 3He spin filter and demonstration for a neutron reflectometer and magnetic imaging technique

International Nuclear Information System (INIS)

Hayashida, H; Kira, H; Miyata, N; Akutsu, K; Mizusawa, M; Parker, J D; Matsumoto, Y; Oku, T; Sakai, K; Hiroi, K; Shinohara, T; Takeda, M; Yamazaki, D; Oikawa, K; Harada, M; Ino, T; Imagawa, T; Ohkawara, M; Ohoyama, K; Kakurai, K

2016-01-01

We have been developing a 3 He neutron spin filter (NSF) using the spin exchange optical pumping (SEOP) technique. The 3 He NSF provides a high-energy polarized neutron beam with large beam size. Moreover the 3 He NSF can work as a π-flipper for a polarized neutron beam by flipping the 3 He nuclear spin using a nuclear magnetic resonance (NMR) technique. For NMR with the in-situ SEOP technique, the polarization of the laser must be reversed simultaneously because a non-reversed laser reduces the polarization of the spin-flipped 3 He. To change the polarity of the laser, a half-wavelength plate was installed. The rotation angle of the half-wavelength plate was optimized, and a polarization of 97% was obtained for the circularly polarized laser. The 3 He polarization reached 70% and was stable over one week. A demonstration of the 3 He nuclear spin flip system was performed at the polarized neutron reflectometer SHARAKU (BL17) and NOBORU (BL10) at J-PARC. Off-specular measurement from a magnetic Fe/Cr thin film and magnetic imaging of a magnetic steel sheet were performed at BL17 and BL10, respectively. (paper)

Observation of Gravitationally Induced Vertical Striation of Polarized Ultracold Neutrons by Spin-Echo Spectroscopy.

Science.gov (United States)

Afach, S; Ayres, N J; Ban, G; Bison, G; Bodek, K; Chowdhuri, Z; Daum, M; Fertl, M; Franke, B; Griffith, W C; Grujić, Z D; Harris, P G; Heil, W; Hélaine, V; Kasprzak, M; Kermaidic, Y; Kirch, K; Knowles, P; Koch, H-C; Komposch, S; Kozela, A; Krempel, J; Lauss, B; Lefort, T; Lemière, Y; Mtchedlishvili, A; Musgrave, M; Naviliat-Cuncic, O; Pendlebury, J M; Piegsa, F M; Pignol, G; Plonka-Spehr, C; Prashanth, P N; Quéméner, G; Rawlik, M; Rebreyend, D; Ries, D; Roccia, S; Rozpedzik, D; Schmidt-Wellenburg, P; Severijns, N; Thorne, J A; Weis, A; Wursten, E; Wyszynski, G; Zejma, J; Zenner, J; Zsigmond, G

2015-10-16

We describe a spin-echo method for ultracold neutrons (UCNs) confined in a precession chamber and exposed to a |B0|=1  μT magnetic field. We have demonstrated that the analysis of UCN spin-echo resonance signals in combination with knowledge of the ambient magnetic field provides an excellent method by which to reconstruct the energy spectrum of a confined ensemble of neutrons. The method takes advantage of the relative dephasing of spins arising from a gravitationally induced striation of stored UCNs of different energies, and also permits an improved determination of the vertical magnetic-field gradient with an exceptional accuracy of 1.1  pT/cm. This novel combination of a well-known nuclear resonance method and gravitationally induced vertical striation is unique in the realm of nuclear and particle physics and should prove to be invaluable for the assessment of systematic effects in precision experiments such as searches for an electric dipole moment of the neutron or the measurement of the neutron lifetime.

Spin-rotation and NMR shielding constants in HCl

Energy Technology Data Exchange (ETDEWEB)

Jaszuński, Michał, E-mail: michal.jaszunski@icho.edu.pl [Institute of Organic Chemistry, Polish Academy of Sciences, 01-224 Warszawa, Kasprzaka 44 (Poland); Repisky, Michal; Demissie, Taye B.; Komorovsky, Stanislav; Malkin, Elena; Ruud, Kenneth [Centre for Theoretical and Computational Chemistry, University of Tromsø—The Arctic University of Norway, N-9037 Tromsø (Norway); Garbacz, Piotr; Jackowski, Karol; Makulski, Włodzimierz [Laboratory of NMR Spectroscopy, Department of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw (Poland)

2013-12-21

The spin-rotation and nuclear magnetic shielding constants are analysed for both nuclei in the HCl molecule. Nonrelativistic ab initio calculations at the CCSD(T) level of approximation show that it is essential to include relativistic effects to obtain spin-rotation constants consistent with accurate experimental data. Our best estimates for the spin-rotation constants of {sup 1}H{sup 35}Cl are C{sub Cl}  = −53.914 kHz and C{sub H}  = 42.672 kHz (for the lowest rovibrational level). For the chlorine shielding constant, the ab initio value computed including the relativistic corrections, σ(Cl) = 976.202 ppm, provides a new absolute shielding scale; for hydrogen we find σ(H) = 31.403 ppm (both at 300 K). Combining the theoretical results with our new gas-phase NMR experimental data allows us to improve the accuracy of the magnetic dipole moments of both chlorine isotopes. For the hydrogen shielding constant, including relativistic effects yields better agreement between experimental and computed values.