publicationDate stringlengths 10 10 | abstract stringlengths 0 37.3k | title stringlengths 1 5.74k | doi stringlengths 11 47 ⌀ |
|---|---|---|---|
2001-12-01 | The use of high-field electron paramagnetic resonance (EPR) made possible for the first time to obtain detailed information on the anisotropy of integer-spin systems, which are usually silent at conventional EPR frequencies. The data obtained so far by different research groups on non-Kramers ions are reviewed within t... | High-frequency EPR: An occasion for revisiting ligand field theory | null |
2001-12-01 | High-frequency and -field electron paramagnetic resonance (HFEPR) has been used to study several complexes of high-spin manganese(III) (3d^4, S = 2): [Mn(Me_2dbm)X] and [Mn(OEP)X] (X = Cl^−, Br^−), where Me_2dbm^− is the anion of 4,4′-dimethyldibenzoylmethane and OEP^2− is the dianion of 2,3,7,8,12,13,17,18-octaethylpo... | High-frequency and -field electron paramagnetic resonance of high-spin manganese(III) in axially symmetric coordination complexes | null |
2001-12-01 | The ground state and several low-lying excited states of the Mg_2 dimer have been studied by means of a combination of the complete-active-space multiconfiguration self-consistent-field (CASSCF)/CAS multireference second-order perturbation theory (CASPT2) method and coupled-cluster with single and double excitations a... | Ab initio calculations for the potential curves and spin–orbit coupling of Mg2 | null |
2001-09-01 | The spin orientation of two-dimensional (2D) electrons by a lateral electric field is considered. The electron dispersion law is assumed to contain linear terms due to the spin-orbit band splitting in an asymmetric quantum well. The coefficient of spin orientation in a DC electric field is found. The mean electron spin... | Spin response of 2D electrons to a lateral electric field | null |
2001-08-01 | The ion and electron plasma experiment on the Fast Auroral Snapshot satellite (FAST) is designed to measure pitch-angle distributions of suprathermal auroral electrons and ions with high sensitivity, wide dynamic range, good energy and angular resolution, and exceptional time resolution. These measurements support the ... | The Electron and ion Plasma Experiment for Fast | null |
2001-08-01 | We have studied in detail the crystal and magnetic structures of the oxyphosphates MFePO_5 (M: divalent transition metal) using neutron powder diffraction as a function of temperature. All of them are isomorphic to the mixed valence compound α -Fe_2PO_5 with space-group Pnma. No disorder exists between the two metallic... | Crystal and magnetic structures of the oxyphosphates MFePO_
5
(M = Fe, Co, Ni, Cu). Analysis of the magnetic ground state in terms of superexchange interactions | null |
2001-07-01 | Excited states of atomic nuclei can have long half lives, due to the angular-momentum couplings of unpaired nucleons. Such isomeric states provide opportunities for exploring novel nuclear physics, astrophysics and physics at the atomic/nuclear interface. This review focuses on the properties of isomers in deformed nuc... | Exotic Isomers in Deformed Atomic Nuclei | null |
2001-06-01 | In the U_xLa_1-xS system there is an abrupt loss of the long-range ferromagnetic ordering found in pure US at a critical concentration x _ c ∼ 0.57 , which is far above the percolation limit. As the magnetic ground state in such a system can be strongly affected by small variations of the 5 f localization, we have inve... | On the evolution of the ground state in the system U_
x
La_
1 - x
S: Polarized neutron diffraction and X-ray magnetic circular dichroism study | null |
2001-04-01 | Recently, efficient spin injection, being the first step towards semiconductor spin electronics, by using BeMnZnSe as a spin filter was accomplished. Such a spin filter made it possible to align the spin orientation of conduction electrons and subsequently inject them into GaAs. However, controlling spin orientation of... | Spin Manipulation Using Magnetic II–VI Semiconductors | null |
2001-03-01 | Sum rule, especially the energy-weighted sum rule (EWSR) of the spin-dipole transition strength is discussed, and the effects of the spin-orbit interaction as well as the kinetic energy term and the tensor interaction on the splitting and distribution of the strength are investigated. Light nuclei such as ^12C and ^16O... | Spin and isospin modes | null |
2001-02-01 | Room temperature Mössbauer spectra of tris( N , N ′-dialkyldithiocarbamato)iron(III) complexes [(R_2NCS_2)_3Fe] (R = Me, Et, n -Pr, i -Pr, n -Bu and i -Bu) exhibit an asymmetric doublet which can be resolved into two doublets, each corresponding to high and low spin states in equilibrium. The quadrupole splitting (Δ E ... | Magnetic moment and Mössbauer spectral studies of spin-crossover in tris(N,N′-dialkyldithiocarbamato)iron(III) complexes and their thermal decomposition | null |
2001-02-01 | The irreducible bases of the icosahedral double groups I′ and I′_h are explicitly presented in their respective group spaces. Applying these bases to the spin states |j, μ〉, we obtain a simple formula for combining the spin states into the symmetry-adapted bases which belong to a given row of given irreducible represen... | Correlations of Spin States for Icosahedral Double Group | null |
2001-01-01 | In quasi two-dimensional electron and hole systems spin-orbit (SO) coupling strongly influences both the orbital and spin components of motion. In inversion asymmetric systems SO coupling causes a spin splitting even at magnetic field B = 0. Often this is analyzed by measuring the Shubnikov-de Haas (SdH) oscillations a... | Spin-Orbit Coupling in Two-Dimensional Electron and Hole Systems | null |
2001-01-01 | The theories connecting the observed NMR chemical shifts and nuclear spin—spin coupling constants to electronic wave functions were published by Norman Ramsey in eight connected Physical Review papers from 1950 to 1953. At the nonrelativistic limit these expressions still stand as the final answer. | Perspective on Norman Ramsey’s theories of NMR chemical shifts and nuclear spin—spin coupling | null |
2001-01-01 | The ion and electron plasma experiment on the Fast Auroral Snapshot satellite (FAST) is designed to measure pitch-angle distributions of suprathermal auroral electrons and ions with high sensitivity, wide dynamic range, good energy and angular resolution, and exceptional time resolution. These measurements support the ... | The Electron and Ion Plasma Experiment for Fast | null |
2001-01-01 | In the formalism of reduced density matrices and functions, using the irreducible tensor-operator technique and the space-spin separation scheme, the matrix elements of one of the main spin-relativistic corrections of the Breit-Pauli Hamiltonian, the spin-orbit interactions, are expressed in a form suitable for numeric... | Reduced Density-matrix Treatment of Spin-orbit Interaction Terms in Many-electron Systems | null |
2001-01-01 | We measured high-quality Co 2 p magnetic circular dichroism (MCD) spectra in photoemission for > 5 ML Co films grown on Cu(1 1 13) using a “complete” experiment, where the sample magnetization and the light helicity vector were reversed separately. We show how the four measured spectra, M^±P^±, can be used to make new ... | Magnetic circular dichroism in Co 2p photoemission of Co/Cu(1 1 13): Separation of the fundamental spectra | null |
2001-01-01 | In this paper, we review a double quantum dot each dot of which is tunnelcoupled to superconducting leads. In the Coulomb blockade regime, a spin-dependent Josephson coupling between two superconductors is induced, as well as an antiferromagnetic Heisenberg exchange coupling between the spins on the double dot which ca... | Superconductors, Quantum Dots, and Spin Entanglement | null |
2001-01-01 | The spin-coupling model of zero-field splitting (ZFS) is developed for trimeric and tetrameric clusters. The spin-dependent correlations between the cluster ZFS parameters D_s and E_s and ZFS parameters D_i and E_i of individual ions were obtained for the mixed-valent (MV) and monovalent trimeric [3Fe-4S] and tetrameri... | Exchange Variation of Zero-Field Splitting in Polynuclear Clusters with High-Spin Ground State | null |
2001-01-01 | This last part of the book sets out to explore several interfaces between noncommutative geometry (NCG) and physics. We have chosen to report on the avenues that look more promising, as the century draws to a close, rather than on the more established “applications”. | Tori | null |
2001-01-01 | Ion Radical Reactions of Fullerenes | null | |
2001-01-01 | Triple differential cross sections, spin asymmetries and branching ratios for (e, 2e) reactions of the 5p 1/2 and 5p3/2 states of Xenon in coplanar asymmetric geometry are analysed within the relativistic distorted wave Born approximation. Our calculations demonstrate unambiguously that relativistic effects in the scat... | Effective Potential Study of (E,2E) Processes with Polarized Electrons | null |
2001-01-01 | The local and average orbital magnetic moments ( L ) of several low-dimensional systems are determined in the framework of a self-consistent tight-binding theory. For transition metal surfaces, results for the local orbital magnetic moments L _δ(i) at different layers i and magnetization directions 8 are discussed. It ... | Orbital Magnetism in Low Dimensional Systems: Surfaces, Thin Films and Clusters | null |
2001-01-01 | When electronic correlations in magnetism and pairing in superconductivity are described in the simplest fashion by the Hubbard model and the BCS model one finds remarkable properties of small systems which are absent in the bulk. We discuss here (for a few selected examples) the present status of the theory of cluster... | Magnetism and Superconductivity in Ultra-Small Particles | null |
2001-01-01 | Rare earths have been used widely in various fields, such as phosphor, magnetic material and superconductor. The effect of rare-earth ions can be divided into two parts: one due to the electron configuration of their 4f orbit, and the other due to their chemical bonding state, e.g. ion radius and chemical bond length. ... | Generation of Induced Structures in Rare-Earth-Ions-Doped Glasses | null |
2001-01-01 | Investigations of the electronic structure of transition-metal oxides with incompletely filled 3d shells have a long history [15]. With the discovery of their insulating behavior, presented at a conference in Bristol in 1937 [27], they were among the first highly correlated systems found, where band theory fails to des... | Electronic Structure of MnO, CoO, and NiO | null |
2001-01-01 | In this chapter, our goal is to construct geometries on commutative spaces. That is to say, given a noncommutative space admitting a differential calculus that is in fact commutative —in other words, an algebra A= C ∞ ( M ) for some differential manifold M — we shall find the extra structures that give rise to geometri... | Commutative Geometries | null |
2001-01-01 | We compare the predictions of recent single and binary star models with respect to several observable features. First, we find that rotationally induced mixing and accretion from a close binary component may lead to almost identical surface abundance patterns — with the boron to nitrogen ratio as a marked exception. We... | Massive Single and Binary Star Models: A Comparison | null |
2001-01-01 | From the degree of circular polarization of the time-resolved radiative recombination of 2D-electrons with photo-excited holes bound to acceptors we have measured the magnetic field dependence of the electron spin polarization for various fractional and Composite Fermions (CF) states. The Fermi energies of these CF sta... | Magneto-optics of Composite Fermions | null |
2001-01-01 | We now come to fulfill the program formulated in chap. 6: to find and classify all quantities that behave linearly under Lorentz transformations just as tensors door in other words, to construct all finite-dimensional representations of the Lorentz group. From the commutation relations one reads off the adjoint represe... | Representation Theory of the Lorentz Group | null |
2000-11-01 | X-ray absorption spectroscopy (XAS) and soft-X-ray magnetic circular dichroism (SXMCD) at the Mn L_2,3-, Cr L_2,3- and O-K edges of Sm_0.5Ca_0.5Mn_1-xCr_xO_3 ( ) bulk polycrystalline samples have been performed at T =20 K below the ferromagnetic Curie temperature. We show the existence of a magnetic sublattice on each ... | Chromium doped manganites: evidence for electronically phase-separated systems | null |
2000-10-01 | A bidentate ligand derived from cinnamaldehyde and acetylacetone and its copper(II) complex have been synthesized and characterized by elemental analysis, UV-Vis, IR, ESR and magnetic susceptibility measurements. Magnetic susceptibility measurements, ESR and electronic spectral data indicate the presence of six coordin... | Copper(II) complex of 3-cinnamalideneacetylacetone: Synthesis and characterisation | null |
2000-09-01 | It is shown that the layered antiferromagnetic order in stoechiometric LaMn0_3 cannot be understood purely from electronic interactions. On the contrary, it mainly results from strong cooperative Jahn-Teller deformation. Those involve a compression of the Mn-O octahedron along the c -axis (mode Q _ 3 < 0 ), while alter... | Stabilization of A-type layered antiferromagnetic phase in LaMnO_3 by cooperative Jahn-Teller deformations | null |
2000-07-01 | We discuss the effects of an applied magnetic field on the low-energy excitations in the low temperature phase of Yb_4As_3. We show also why the magnetic interaction of the Yb^3+ ions is nearly of an isotropic Heisenberg spin-1/2 type. A small anisotropy due to an intrachain dipolar interaction leads to the opening of ... | Low-energy excitations of Yb
As
in a magnetic field | null |
2000-07-01 | We argue that compatibility with elementary particle physics requires gravitational theories with torsion to be unable to distinguish between orbital angular momentum and spin. An important consequence of this principle is that spinless particles must move along autoparallel trajectories, not along geodesics. | Universality Principle for Orbital Angular Momentum and Spin in Gravity with Torsion | null |
2000-05-01 | A relativistic pseudopotential of the energy-consistent variety simulating the Tl^21+ (1 s – 4 f ) core has been generated by adjustment to multiconfiguration Dirac–Hartree–Fock data based on the Dirac–Coulomb–Breit Hamiltonian. Valence ab initio calculations using this pseudopotential have been performed for atomic e... | A small-core multiconfiguration Dirac–Hartree–Fock-adjusted pseudopotential for Tl – application to TlX (X = F, Cl, Br, I) | null |
2000-05-01 | The reaction of nitric oxide with ZSM-5 zeolite ion-exchanged by Co(II) (Co-ZSM-5) has been studied by electron spin resonance (ESR), Fourier transform infrared (FTIR) and diffuse reflectance ultraviolet-visible spectroscopy. When dehydrated Co-ZSM-5 reacts at room temperature with nitric oxide, the ESR spectrum of Co(... | Electron spin resonance and optical spectroscopic studies of Co-ZSM-5 with nitric oxide | null |
2000-03-01 | Results of high-energy magnetic X-ray diffraction on pure antiferromagnetic chromium are presented. The temperature dependence of the propagation vector of the spin-density wave (SDW) and the strain-wave (SW) could be reproduced. The temperature dependence of the magnetic integrated intensity could be measured in the t... | Form-factor measurements on chromium with high-energy synchrotron radiation | null |
2000-03-01 | The ESR spectra from Mo^5+ ions in KTiOPO_4 single crystal were studied at 77 K. The ESR spectra reveal two different types of paramagnetic centers, one due to Mo^5+ which occupy the Ti(1) position in the crystal and the other, due to Ti^3+, formed at position Ti(2) in the crystal. The principal values and direction co... | Electron spin resonance of MO5+ in KTiOPO4 | null |
2000-02-01 | The theories connecting the observed NMR chemical shifts and nuclear spin–spin coupling constants to electronic wave functions were published by Norman Ramsey in eight connected Physical Review papers from 1950 to 1953. At the nonrelativistic limit these expressions still stand as the final answer. | Perspective on Norman Ramsey's theories of NMR chemical shifts and nuclear spin–spin coupling
| null |
2000-02-01 | The reorientation of the magnetization of a ferromagnetic monolayer is calculated with the help of many-body Green's function theory. This allows, in contrast to other spin wave theories, a satisfactory calculation of magnetic properties over the entire temperature range of interest since interactions between spin wave... | Field-induced magnetic reorientation and effective anisotropy of a ferromagnetic monolayer within spin wave theory | null |
2000-01-01 | This is a slightly updated summary of the new results which were presented at the 13^th International Symposium on High Energy Spin Physics, that was held at IHEP-Protvino during 7–12, September 1998. I subdivided the results into the topics of: spin physics history; polarized beams and Siberian snakes; polarized targe... | Status of spin physics | null |
2000-01-01 | A nuclear resonance fluorescence experiment on ^88Sr has been performed with bremsstrahlung of 6.7 MeV endpoint energy. The γ-ray linear polarisation has been measured with a EUROBALL CLUSTER detector used as a Compton polarimeter. The results indicate positive parity for the J= 1 state at 4.742 MeV in ^88Sr, in contra... | Is the 4.742 MeV state in ^88Sr the 1^− two-phonon state? | null |
2000-01-01 | Following van der Waerden, the Dirac equation is derived from linearization of the Klein-Gordon equation using the algebraic properties of the Pauli spin matrices. As the algebra of these matrices is identical to that of quaternions, the Dirac equation can be reformulated in terms of quaternion algebra and therefore wi... | Quaternion symmetry of the Dirac equation | null |
2000-01-01 | In 1930 W. Pauli postulated the existence of the neutrino in order to guarantee the energy and momentum conservation for the weak interaction, which at that time seemed to be violated in the β -decay experiments. Since the energy of the neutrino could not be determined even in the most sensitive measurements of the β d... | The Weyl Equation — The Neutrino | null |
2000-01-01 | For a system built from state vectors, ❘ j _1 m _1〉 and ❘ j _2m_2〉 express the angular momentum—coupled state vector ❘ j _1 j _2 jm 〉 for the rotated system in terras of the uncoupled state vectors, also in the rotated system | The Clebsch—Gordan Series | null |
2000-01-01 | The s -wave differential equations for the Yakubovsky components characterizing the nnpp system have been solved by the method of cluster reduction. Two-cluster scattering at energies below the three-particle threshold in the singlet and triplet spin states has been considered. The MT I–III potential model has been use... | Investigation of low-energy scattering in the nnpp system on the basis of differential equations for Yakubovsky components in configuration space | null |
1999-12-01 | We report ab initio calculations of the indirect nuclear spin–spin coupling constants of PbH_4 using a basis set which was specially optimized for correlated calculations of spin–spin coupling constants. All nonrelativistic contributions and the most important part of the spin–orbit correction were evaluated at the lev... | Calculations of the indirect nuclear spin–spin coupling constants of PbH4 | null |
1999-12-01 | We study the electron transmission tuned by quantum gate in an Aharonov-Casher (AC) ring. Transmission probability is obtained as a function of the normalized textured electric fields and Fermi energy. We find that modulating electron wavefunction in the stub can drastically affects electron transmission through the ri... | Transmission modulated by quantum gate in aharonov-casher ring | null |
1999-12-01 | The isotherms of adsorption of MeX_2 (Me = Cu^2+, Co^2+; X = Cl^−, Br^−, ClO _4 ^− ) by silica gel chemically modified with 2-mercaptoimidazole (SiMI) were studied in acetone and ethanol solutions, at 25 °C. Covalently attached 2-mercaptoimidazole molecule to silica gel surface adsorbs MeX_2 from solvent by forming a s... | Adsorption of Cu(II) and Co(II) complexes on a silica gel surface chemically modified with 2-mercaptoimidazole | null |
1999-12-01 | A model heme complex, bis(3-aminopyrazole)tetraphenylporphinatoiron(III) chloride, [TPPFe (NH_2PzH)_2]Cl, for which the EPR g -values lead to a rhombicity V /Δ=1.2 if g _ zz is the largest g -value, have been investigated by electron spin echo envelope modulation (ESEEM) and Mössbauer spectroscopies. The ESEEM studies... | ESEEM and Mössbauer studies of the ferriheme model compound bis(3-aminopyrazole)tetraphenylporphyrinatoiron(III) chloride, [TPPFe(NH_2PzH)_2]Cl | null |
1999-10-01 | The magnetic properties of (La_1 − x Sr_ x )MnO_3 crystals have been studied. The ac susceptibility χ = χ ′ + i χ ″ has been measured at frequencies ranging from 10 Hz to 1 000 Hz. The x = 0.25 crystal shows a typical ferromagnetic behaviour with a dimensionless SI susceptibility of 6 below T _c = 350 K limited by the ... | Weak ferromagnetism in LaMnO_3
| null |
1999-10-01 | Due to the outstanding brightness of Comet Hale-Bopp measurements of water production rates were possible over a wide range of heliocentric distances (up to 5 AU). A variety of observing techniques have been used, including radio observations, IR- and UV-measurements. The H_2O-production of a comet is closely connected... | H2O-Activity of Comet Hale-Bopp | null |
1999-08-01 | We review the experimental evidence for spin-triplet superconductivity in Sr_2RuO_4. The Knight shift experiments decisively demonstrated that the Cooper-pair symmetry is spin triplet. We discuss the most probable wave function of the Cooper pairs on the basis of the results of a number of key experiments. We point out... | Experimental Evidence for Spin-Triplet Superconductivity in Sr2RuO4 | null |
1999-06-01 | Angularly and temperature-dependent electron spin resonance (ESR) measurements on single crystals of the organic superconductor κ-(bis(ethylenedithiolo)-tetrathiafulvalene)_2I_3 are reported. The results on the anisotropy of the g -value, the temperature dependence of the susceptibility as well as of the ESR linewidth ... | Electron spin resonance measurements on single crystals of the organic superconductor κ-(BEDT-TTF)_2I_3
| null |
1999-05-01 | Electron spin resonance on samarium ions with stabilized valence Sm^3+ is investigated in the fluctuating-valence semiconductor SmB_6, both pure and doped with the rare-earth ions Eu^2+, Er^3+, and Gd_3+. The dynamic and static Jahn-Teller effects have been observed for the first time on rare-earth ions. The relation b... | Jahn-Teller effect on Sm^3+ ions in SmB_6
| null |
1999-02-01 | An internal polarized gas target in conjunction with a beam of polarized protons stored in the IUCF Cooler storage ring has been used to measure analyzing power and spin correlation parameters between 200 MeV and 450 MeV over a wide range of angles. A consistent absolute beam and target polarization calibration was est... | Spin correlation in pp elastic scattering and in pion production near threshold | null |
1999-01-01 | In this talk I give a brief update on the recent progress in the SO (5) theory of high T_c superconductivity [1]. Reviewed topics include SO (5) ladders, the unification of BCS and SDW quasi-particles in the SO (5) theory and the microscopic origin of the condensation energy. | A Progress Report on the SO(5) Theory of High T_c Superconductivity | null |
1999-01-01 | In high T _ c superconductors grain boundary junctions are important as weak links, and can be used to construct superconducting rings exhibiting half-integer flux quantisation. We investigate supercurrent flow in such junctions for both s-wave and d-wave pairing scenarios. We show that the supercurrent is an approxima... | Junctions and interfaces in D-wave superconductors | null |
1999-01-01 | Electron impact ionization of atoms is an important collision process whose knowledge is of relevance in several fields, e.g. in the physics of the upper atmosphere, in plasma formation, and in gas discharges. The understanding of the ionization reaction, e ^- + A → A ^+ + e ^- + e ^-, has seen continuous improvement t... | (e,2e) Measurements on Lithium with Spin — Polarized Beams of Electrons and Atoms | null |
1999-01-01 | We discuss the electronic properties of a system of interacting electrons in a narrow channel in the quantum Hall effect regime. We demonstrate that the system undergoes phase transitions when then strength of the interaction or the geometry of the channel is varied. The resulting phase diagram contains odd-denominator... | Interacting electrons in a narrow quantum hall system | null |
1998-12-01 | We present correlated calculations of the indirect nuclear spin-spin coupling constants of HD, HF, H_2O, CH_4, C_2H_2, BH, AlH, CO and N_2 at the level of the second-order polarization propagator approximation (SOPPA) and the second-order polarization propagator approximation with coupled-cluster singles and doubles am... | Correlated calculations of indirect nuclear spin-spin coupling constants using second-order polarization propagator approximations: SOPPA and SOPPA(CCSD) | null |
1998-11-01 | The spin-orbit and the spin-spin coupling constants of the ^4Π_g state of the He_2 ^− ion, of the parent a^3Σ_u ^+, and of the b^3Π_g states of He_2 have been evaluated by a multireference configuration interaction method. The theoretical spin-spin splittings of the a^3Σ_u ^+ state and the R -dependent spin-spin functi... | Spin-orbit and spin-spin couplings in He2 and He2− | null |
1998-11-01 | This paper solves the problem of the interaction, via the field of virtual photon field with the emission or absorption of a real photon, of two atomic electrons located at arbitrary distances from one another. The interaction is interpreted as a third-order QED effect in the coordinate representation. The role of inte... | The problem of two electrons in an external field and the method of integral equations in optics | null |
1998-11-01 | An implementation of analytic open-shell UHF-CCSD(T) second derivatives is presented. To demonstrate applicability and test the accuracy of the UHF-CCSD(T) approach for the determination of spectroscopical parameters, vibration-rotation interaction constants were calculated for the ground (1^2Π) and first electronicall... | Analytic UHF-CCSD(T) second derivatives: implementation and application to the calculation of the vibration-rotation interaction constants of NCO and NCS | null |
1998-11-01 | Orbital ionization energies are compared with the results of ab initio calculations for three-atomic linear BeCl_2, XeF_2, CrCl_2 and five-atomic tetrahedral TiCl_4, RuO_4 molecules to investigate the effect of electron relaxation in ions on the informativity of photoelectron spectra of molecules and complex compounds.... | Photoelectron spectroscopy of transition metal complexes. Effect of electron relaxation on spectrum informativity | null |
1998-09-01 | A Gauge Theory that contains the pion triplet as strong force quanta, a quantum theory of gravity and unifies the strong (nuclear) and gravitational interactions is proposed under a relaxation of the requirement of covariance for Lorentz boost transformations. A modified form of local gauge invariance in which the nucl... | A unified theory of spin 0 nuclear interactions | null |
1998-08-01 | Using time-resolved CIDEP and conventional ESR as well as optical studies much can be elucidated concerning the initial photochemical reactions of lignin model compounds such as α-guaiacoxyacetoveratrone and α-guaiacoxy-β-propioveratrone. The resulting transient radicals are models for intermediates in the processes of... | Applications of ESR and CIDEP to mechanistic studies of lignin chemistry | null |
1998-05-01 | The convergence of NMR indirect spin-spin coupling constants with the extension of the basis set is analyzed, based on calculations carried out at the multiconfigurational self-consistent-field level for the HF and H_2O systems. For the dominant and difficult Fermi-contact contribution, the standard correlation-consist... | Basis-set dependence of nuclear spin-spin coupling constants | null |
1998-04-01 | The eigenvalue problem of a Hamiltonian represented in a finite-dimensional model space being the N -electron subspace of the 2 K -spinorbital Fock space is analyzed. It is pointed out that the permutation group S _ N is a very convenient framework for this analysis. The resulting approach is known as the symmetric gro... | Symmetric‐group‐based methods in quantum chemistry | null |
1998-02-01 | Relativistic two-electron operators obtained by the Douglas-Kroll transformation contain p-dependent kinematic prefactors which are not present in the corresponding Breit-Pauli operators. These factors are usually calculated using a resolution of the identity approach, which requires integral transformations. In the pr... | An efficient treatment of kinematic factors in pseudo-relativistic calculations of electronic structure | null |
1998-01-01 | The magnetism of lamellar copper oxides, which are the parent materials of high temperature superconductors, is dominated by the spin 1/2 Cu^+2 ions on the CuO_2 planes. The magnetic behavior of these planes at high temperature is described well by the planar quantum Heisenberg antiferromagnetic (AFM) model, which has ... | Low Dimensional Quantum Magnetism in the Copper Oxides | null |
1998-01-01 | I discuss the spectrum of hadrons containing heavy quarks ( b or c ), and how well the experimental results are matched by theoretical ideas. Useful insights come from potential models and applications of Heavy Quark Symmetry and these can be compared with new numerical results from the ab initio methods of Lattice QCD... | The heavy hadron spectrum | null |
1998-01-01 | The magnetic susceptibility x of the itinerant antiferromagnetic compound UGa_3 has been studied experimentally under pressure up to 2 kbar in the temperature range 64–300 K. This study reveals a pronounced pressure effect on magnetic properties of UGa_3 and the measured pressure derivative of the Néel temperature is f... | Atomic Volume Effect on Electronic Structure and Magnetic Properties of UGa_3 Compound
| null |
1998-01-01 | Nearly one-dimensional magnetic systems can be obtained by growing materials in which the magnetic ions have strong exchange interactions along atomic chains but much weaker interactions between the chains. By suitable choice of the magnetic ions and their environment the interactions can be varied to give realisations... | The Excitations of One-Dimensional Spin 1/2 Antiferromagnets | null |
1998-01-01 | The electrical conductivity of the superlattice systems Ni/Co, Ni/Cu, and Pd/Ag, as a function of layer thickness, is investigated theoretically. Experimentally an oscillatory dependence was found for the first two, while the latter exhibits a monotonous behavior. First, a band theory based calculation is carried out, ... | Conductivity Oscillations of Magnetic Multilayers | null |
1998-01-01 | By using a Monte Carlo transport model, we investigate the feasibility of the control of the electron spin rotation by a perpendicular electric field in a III-V two dimensional electron gas. At room temperature, this control is made difficult because of an important spin relaxation phenomenon due to the scattering even... | Monte Carlo modelling of spin relaxation in a III-V two dimensional electron channel | null |
1998-01-01 | The thyroid gland, which has a central role in the control of metabolism via T_3 and T_4 hormones, is the target of the most common autoimmune diseases [1]. The thyroid hormone precursor is thyroglobulin (TG), which is iodinated on tyrosine residues. A fraction of these residues is coupled to form T_4, which is deiodin... | Thyroid autoantigens | null |
1998-01-01 | Many enzymes [1–10] successfully catalyse the oxidation of alkanes, even the most inert ones such as methane. The precise architecture of their active site allows such catalytic properties. Such an active site contains a dinuclear iron core, in which μ_2-O or μ_2-OH bridging is observed. The environment in which the ac... | Mono- and Binuclear Iron Complexes in Zeolites and Mesoporous Oxides as Biomimetic Alkane Oxidation Catalysts | null |
1997-12-01 | Anomalous properties of the magnetization, the crystal dilatation, and other physical quantities observed in the mixed state of compounds such as UPd_2Al_3 and CeRu_2 suggest the occurrence of a new state near H _ c 2. In such compounds with large spin susceptibility and high H _ c 2, a new inhomogeneous superconductin... | Generalized Fulde-Ferrell-Larkin-Ovchinnikov state in heavy-fermion and intermediate-valence systems | null |
1997-12-01 | The operator formalism of quantum mechanics is applied to the problem of reflection and transmission of non-relativistic spin particles at stratified media. Two basic numerical methods in optics of stratified media, the matrix method of Abeles and the formalism of Airy, have been thus generalized for non-relativistic s... | Spin particles at stratified media: operator approach | null |
1997-11-01 | We discuss some of the unusual characteristics of a Fermi superfluid formed by Cooper pairing in a system, such as spin-polarized ^6Li, which possesses triple nuclear spin degeneracy. In particular we show (a) that the “ naive” BCS expression for the transition temperature is (unlike in the usual spin-1/2 case) exact i... | Some Properties of a Spin-1 Fermi Superfluid: Application to Spin-Polarized ^6Li | null |
1997-11-01 | We discuss some of the unusual characteristics of a Fermi superfluid formed by Cooper pairing in a system, such as spin-polarized^6Li, which possesses triple nuclear spin degeneracy. In particular we show (a) that the “naive” BCS expression for the transition temperature is (unlike in the usual spin-1/2 case) exact in ... | Some properties of a spin-1 fermi superfluid: Application to spin-polarized^6Li | null |
1997-10-01 | A general configuration interaction (CI) algorithm incorporating one- and two-electron spin-orbit operators is presented. The algorithm is determinant based and enables the use of highly vectorized non-relativistic algorithms in the most operation-intensive part. Excitations between α and β spin orbitals are avoided in... | A determinantal approach to spin-orbit configuration interaction | null |
1997-10-01 | The splitting between the ${} ^2P_{3 \over 2} $ and the ${} ^2P_{1 \over 2} $ terms in the thallium atom has been calculated at the perturbation theory level and by spin-orbit CI calculations, using both the Breit-Pauli and the no-pair form of the microscopic spin-orbit Hamiltonian. The importance of the spin-other-orb... | Ab initio calculations of the
${} ^2{\bi P}_{{\b 1}\over {\b 2}} \hbox{-}{} ^2{\bi P}_{{\b 3} \over {\b 2}} $ splitting in the thallium atom | null |
1997-10-01 | Detailed formulae for the implementation of the multi-configuration SCF spinor optimization in a basis of Kramers pair 2-spinors – i.e. exploiting time-reversal symmetry – are presented. Full expressions for the spinor gradient and spinor Hessian elements are given in abstract form as well as within the usual CASSCF su... | Spinor optimization for a relativistic spin-dependent CASSCF program | null |
1997-10-01 | The electron spin resonance (ESR) spectra of undoped and manganese-doped BSCCO (2212) crystals (nominal composition Bi_2Sr_2CaCu_2– x Mn_xO_y, where x =0.1) are compared. | Electron spin resonance in manganese-doped BSCCO (2212) crystals | null |
1997-09-01 | The major attraction of fast-spin-echo (FSE) imaging is reduced acquisition time; however, careful review of the literature reveals many weaknesses: phase-encoded blurring, truncation artefact, bright fat signal, reduced magnetic susceptibility and increased motion artefact. Our aim was a prospective, blinded compariso... | Fast spin echo vs conventional spin echo in cervical spine imaging | null |
1997-07-01 | Relativistic effects strongly influence the nuclear quadrupole coupling of atoms, molecules or solids. As first shown by Casimir in 1936, in the atomic or single-centre case, for the two states j = l ± s , three radial electric-field-gradient (EFG) integrals, R _++, R _+−, and R , must be introduced. The relativistic c... | Relativistic effects in nuclear quadrupole coupling | null |
1997-07-01 | Based on comparison of the results of ab initio and semiempirical configuration-interaction calculations, we have plotted the potential energy surface for the ground state and a number of low-lying excited states of ozone which correlate with the three lowest dissociation limits. We calculate the matrix elements for th... | Role of spin-orbit coupling in processes of synthesis and photodegradation of ozone | null |
1997-05-01 | A series of C_60 fullerene derivatives containing a nitroxide group has been photoexcited by short LASER pulses in the microwave cavity of a cw-EPR spectrometer. Strongly spin polarized signals have been observed, in glassy matrix as well as in liquid solution, for both the ground electronic state and the excited quart... | Spin polarization in fullerene derivatives containing a nitroxide group. Observation of the intermediate photoexcited quartet state in radical triplet pair interaction | null |
1997-04-01 | The dependence of the residual polarization of negative muons in n‐type Si with impurity concentration (1.6\pm 0.2)\times 10^13\ cm^-3 on temperature in the 10–300 K range has been investigated. Measurements were carried out in external magnetic field of 0.08 T transverse to the muon spin. Muon spin relaxation and freq... | Anomalous frequency shift of negative muon spin precession in n‐type silicon | null |
1997-03-01 | It is shown that the formation of tunnel paramagnetic centers — triplet spin centers with a strongly different adiabatic potential in different spin states — can form in copper oxides based on CuO clusters. The results of measurements of the magnetization and magnetostriction of CuO single crystals are reported. They a... | Nonequilibrium spin states and tunnel paramagnetic centers in copper oxide CuO | null |
1997-02-01 | X-band e.s.r. spectra of copper(II) complexes of empirical formula Cu(Sal.NCH2CH2O)X (where X= H2O, py or Cl) and [Cu(Sal.NCH2CH2CH2O)]2 (Sal.N= OC6H4CHN) in solid and solution states at room temperature and at 77K are reported. In frozen solution at 77K the spectra show axial symmetry with a dx2−y2 ground state. The i... | An e.s.r. study of copper(II) complexes of N-hydroxyalkylsalicylideneimines | null |
1997-01-01 | Using the quadratic response function at the ab initio SCF level of approximation we have calculated the relativistic corrections from the spin-orbit Hamiltonian, H ^SO, to the indirect nuclear spin-spin coupling constants of XH_4 (X = C, Si, Ge, and Sn). We find that the spin-orbit contributions to J _X-H are small, a... | Spin-orbit corrections to the indirect nuclear spin-spin coupling constants in XH_4 (X = C, Si, Ge, and Sn) | null |
1997-01-01 | Using the quadratic response function at the ab initio SCF level of approximation we have calculated the relativistic corrections from the spin–orbit Hamiltonian, H ^SO, to the indirect nuclear spin–spin coupling constants of XH_4 (X=C, Si, Ge, and Sn). We find that the spin–orbit contributions to J _X–H are small, am... | Spin–orbit corrections to the indirect nuclear spin–spin coupling constants in XH4 (X=C, Si, Ge, and Sn) | null |
1997-01-01 | Let me start with some historical remarks before I will concentrate on recent experimental advances on scattering experiments involving polarized electrons. Collisions of electrons with atoms and molecules have been studied for about one hundred years. The general behaviour of the cross section for those collisions is ... | Scattering of Polarized Electrons from Atoms and Molecules | null |
1997-01-01 | Two centuries after the discovery of the rare earths (R) by Lt. C.A Arrhenius (1787) the investigation of the properties of R ions is still an exciting field in solid state physics [1]. The interest in compounds containing rare earths was further enhanced by the discovery of high-temperature superconductivity (HTSC) by... | Neutron Spectroscopy of Rare Earths in Superconducting Materials | null |
1997-01-01 | The study of chiral or ”handed” effects holds a particular fascination, as well as being of fundamental importance. Nature abounds with chiral objects but unfortunately, from a computational point of view, they are quite complicated, as can be seen immediately from their definition. A chiral molecule is distinguishable... | Chiral Effects in Electron Scattering by Molecules | null |
1997-01-01 | This review is an updated version of the lectures presented at the ’92 Banz workshop. Originally it also contained a section on deep inelastic scattering at HERA. Since this subject is now extensively covered in the review by A. Levy, it has been skipped in these lecture notes. They therefore only summarise the actual ... | Quark-gluon structure of the nucleon | null |
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