Showing papers on "Spin-½ published in 2004"
TL;DR: Spintronics, or spin electronics, involves the study of active control and manipulation of spin degrees of freedom in solid-state systems as discussed by the authors, where the primary focus is on the basic physical principles underlying the generation of carrier spin polarization, spin dynamics, and spin-polarized transport.
Abstract: Spintronics, or spin electronics, involves the study of active control and manipulation of spin degrees of freedom in solid-state systems. This article reviews the current status of this subject, including both recent advances and well-established results. The primary focus is on the basic physical principles underlying the generation of carrier spin polarization, spin dynamics, and spin-polarized transport in semiconductors and metals. Spin transport differs from charge transport in that spin is a nonconserved quantity in solids due to spin-orbit and hyperfine coupling. The authors discuss in detail spin decoherence mechanisms in metals and semiconductors. Various theories of spin injection and spin-polarized transport are applied to hybrid structures relevant to spin-based devices and fundamental studies of materials properties. Experimental work is reviewed with the emphasis on projected applications, in which external electric and magnetic fields and illumination by light will be used to control spin and charge dynamics to create new functionalities not feasible or ineffective with conventional electronics.
9,158 citations
TL;DR: It is argued that in a high-mobility two-dimensional electron system with substantial Rashba spin-orbit coupling, a spin current that flows perpendicular to the charge current is intrinsic, and the intrinsic spin-Hall conductivity has a universal value for zero quasiparticle spectral broadening.
Abstract: We describe a new effect in semiconductor spintronics that leads to dissipationless spin currents in paramagnetic spin-orbit coupled systems. We argue that in a high-mobility two-dimensional electron system with substantial Rashba spin-orbit coupling, a spin current that flows perpendicular to the charge current is intrinsic. In the usual case where both spin-orbit split bands are occupied, the intrinsic spin-Hall conductivity has a universal value for zero quasiparticle spectral broadening.
1,639 citations
Posted Content•
TL;DR: This work describes quantum many--body systems in terms of projected entangled--pair states, which naturally extend matrix product states to two and more dimensions, and uses this result to build powerful numerical simulation techniques to describe the ground state, finite temperature, and evolution of spin systems in two and higher dimensions.
Abstract: We describe quantum many--body systems in terms of projected entangled--pair states, which naturally extend matrix product states to two and more dimensions. We present an algorithm to determine correlation functions in an efficient way. We use this result to build powerful numerical simulation techniques to describe the ground state, finite temperature, and evolution of spin systems in two and higher dimensions.
613 citations
TL;DR: In this paper, a generalization of the Lieb-Schultz-Mattis theorem to higher-dimensional spin systems is shown, which is based on the spin operators of the theory.
Abstract: A generalization of the Lieb-Schultz-Mattis theorem to higher-dimensional spin systems is shown. The physical motivation for the result is that such spin systems typically either have long-range order, in which case there are gapless modes, or have only short-range correlations, in which case there are topological excitations. The result uses a set of loop operators, analogous to those used in gauge theories, defined in terms of the spin operators of the theory. We also obtain various cluster bounds on expectation values for gapped systems. These bounds are used, under the assumption of a gap, to rule out the first case of long-range order, after which we show the existence of a topological excitation. Compared to the ground state, the topologically excited state has, up to a small error, the same expectation values for all operators acting within any local region, but it has a different momentum.
581 citations
TL;DR: The discovery of light-induced spin transition at cryogenic temperatures in a series of iron(II) spin-crossover compounds in 1984 has had an enormous impact on spin crossover research as mentioned in this paper.
Abstract: The discovery of a light-induced spin transition at cryogenic temperatures in a series of iron(II) spin-crossover compounds in 1984 has had an enormous impact on spin-crossover research. Apart from being an interesting photophysical phenomenon in its own right, it provided the means of studying the dynamics of the intersystem crossing process between the high-spin and the low-spin state in a series of compounds and over a large temperature range. It could thus be firmly established that intersystem crossing in spin-crossover compounds is a tunnelling process, with a limiting low-temperature lifetime below 50 K and a thermally activated region above 100 K. This review begins with an elucidation of the mechanism of the light-induced spin transition, followed by an in depth discussion of the chemical and physical factors, including cooperative effects, governing the lifetimes of the light-induced metastable states.
458 citations
TL;DR: The localizable entanglement in familiar spin systems is analyzed and the results on the hand of the Ising spin model are illustrated, in which characteristic features for a quantum phase transition such as a divergingEntanglement length are observed.
Abstract: We consider pure quantum states of N>>1 spins or qubits and study the average entanglement that can be localized between two separated spins by performing local measurements on the other individual spins. We show that all classical correlation functions provide lower bounds to this localizable entanglement, which follows from the observation that classical correlations can always be increased by doing appropriate local measurements on the other qubits. We analyze the localizable entanglement in familiar spin systems and illustrate the results on the hand of the Ising spin model, in which we observe characteristic features for a quantum phase transition such as a diverging entanglement length.
387 citations
TL;DR: In this article, a generalized stochastic Landau-Lifshitz equation and its corresponding Fokker-Planck equation were proposed for the magnetization dynamics in the presence of spin-transfer torques.
Abstract: We propose a generalized stochastic Landau-Lifshitz equation and its corresponding Fokker-Planck equation for the magnetization dynamics in the presence of spin-transfer torques. Since the spin-transfer torque can pump a magnetic energy into the magnetic system, the equilibrium temperature of the magnetic system is ill defined. We introduce an effective temperature based on a stationary solution of the Fokker-Planck equation. In the limit of high-energy barriers, the law of thermal agitation is derived. We find that the N\'eel-Brown relaxation formula remains valid as long as we replace the temperature by an effective one that is linearly dependent on the spin torque. We carry out the numerical integration of the stochastic Landau-Lifshitz equation to support our theory. Our results agree with existing experimental data.
378 citations
Journal Article•
TL;DR: In this paper, structural modifications due to spin crossover are first estimated, these include the expansion and the distortion of the FeN 6 octahedron, the isotropic and the anisotropic changes of the unit cell.
Abstract: The interplay between the spin crossover and the structural properties of the complexes in the solid state is still under investigation. In particular the following questions may be asked. What are the structural modifications of the metal coordination sphere at the spin crossover? How are the dimensions and the symmetry of the crystallographic unit cell affected by the spin crossover? Conversely, how may structural properties influence the spin crossover behavior? Do intramolecular parameters account for the features of the spin crossover? What are the relevant characteristics of the crystal packing for the cooperativity? Do the above questions have general answers that can be used for all the spin crossover compounds? This contribution tries to give answers to these questions. The discussion is based on a large structural data set provided in the literature for the six-coordinated iron(II) mononuclear complexes of general formula [FeL n (NCS) 2 ]. The effects of temperature, light and pressure on the X-ray diffraction crystal structures are reviewed. The structural modifications due to the spin crossover are first estimated, these include the expansion and the distortion of the FeN 6 octahedron, the isotropic and the anisotropic changes of the unit cell. The influence of the structural properties on the features of the spin crossover is then discussed. For example, intramolecular properties such as Fe-N bond lengths are in general not relevant to account for the spin crossover features. In contrast, hydrogen bonds play a paramount role in the propagation of the spin conversion throughout the crystal lattice.
343 citations
TL;DR: The equilibrium spin configuration in the F=1 manifold is measured for different magnetic fields and found to show ferromagnetic behavior for low field gradients.
Abstract: We measure spin mixing of $F=1$ and $F=2$ spinor condensates of $^{87}\mathrm{Rb}$ atoms confined in an optical trap. We determine the spin mixing time to be typically less than 600 ms and observe spin population oscillations. The equilibrium spin configuration in the $F=1$ manifold is measured for different magnetic fields and found to show ferromagnetic behavior for low field gradients. An $F=2$ condensate is created by microwave excitation from the $F=1$ manifold, and this spin-2 condensate is observed to decay exponentially with time constant 250 ms. Despite the short lifetime in the $F=2$ manifold, spin mixing of the condensate is observed within 50 ms.
315 citations
TL;DR: In this paper, the authors demonstrate the movement of a head-to-head domain wall through a magnetic nanowire of permalloy (Ni81Fe19) by passing an electrical current through the domain wall and without any external magnetic field applied.
Abstract: We demonstrate movement of a head-to-head domain wall through a magnetic nanowire of permalloy (Ni81Fe19) simply by passing an electrical current through the domain wall and without any external magnetic field applied. The effect depends on the sense and magnitude of the electrical current and allows direct propagation of domain walls through complex nanowire shapes, contrary to the case of magnetic-field–induced propagation. The efficiency of this mechanism has been evaluated and the effective force acting on the wall has been found equal to 0.44 × 10−9 N A−1.
313 citations
01 Mar 2004
TL;DR: The direct measurement of coherent electron spin precession in zero magnetic field as the electrons drift in response to an applied electric field is reported, providing a flexible approach for enabling electrical control over electron spins using strain engineering.
TL;DR: Nonlocal spin control is demonstrated by suppressing and splitting Kondo resonances in one quantum dot by changing the electron number and coupling of the other dot, suggesting an approach to non local spin control that may be relevant to quantum information processing.
Abstract: The effective interaction between magnetic impurities in metals that can lead to various magnetic ground states often competes with a tendency for electrons near impurities to screen the local moment (known as the Kondo effect). The simplest system exhibiting the richness of this competition, the two-impurity Kondo system, was realized experimentally in the form of two quantum dots coupled through an open conducting region. We demonstrate nonlocal spin control by suppressing and splitting Kondo resonances in one quantum dot by changing the electron number and coupling of the other dot. The results suggest an approach to nonlocal spin control that may be relevant to quantum information processing.
TL;DR: In this article, the relative strengths of Rashba and Dresselhaus terms describing spin-orbit coupling in semiconductor quantum well (QW) structures are extracted from photocurrent measurements on n-type InAs QWs containing a two-dimensional electron gas (2DEG).
Abstract: The relative strengths of Rashba and Dresselhaus terms describing the spin-orbit coupling in semiconductor quantum well (QW) structures are extracted from photocurrent measurements on n-type InAs QWs containing a two-dimensional electron gas (2DEG). This novel technique makes use of the angular distribution of the spin-galvanic effect at certain directions of spin orientation in the plane of a QW. The ratio of the relevant Rashba and Dresselhaus coefficients can be deduced directly from experiment and does not relay on theoretically obtained quantities. Thus our experiments open a new way to determine the different contributions to spin-orbit coupling.
TL;DR: A generalization of spin-transfer torques in ferromagnetic structures is proposed, and it is demonstrated that the spin torque can generate bulk and surface spin excitations that have been seen in point-contact experiments.
Abstract: A generalization of spin-transfer torques in ferromagnetic structures is proposed. For a spatially nonuniform magnetization, the spin torque has a form nearly identical to that in magnetic multilayers. We show that the domain-wall motion driven by the current has many unique features that do not exist in the conventional domain-wall motion driven by a magnetic field. We also demonstrate that the spin torque can generate bulk and surface spin excitations that have been seen in point-contact experiments.
TL;DR: The rich dynamics in F=2 spinor Bose-Einstein condensates of 87Rb are experimentally investigated and an interplay between mean-field driven spin dynamics and hyperfine-changing losses in addition to interactions with the thermal component is observed.
Abstract: We experimentally investigate and analyze the rich dynamics in $F=2$ spinor Bose-Einstein condensates of $^{87}\mathrm{R}\mathrm{b}$. An interplay between mean-field driven spin dynamics and hyperfine-changing losses in addition to interactions with the thermal component is observed. In particular, we measure conversion rates in the range of ${10}^{\ensuremath{-}12}\text{ }\text{ }{\mathrm{c}\mathrm{m}}^{3}\text{ }{\mathrm{s}}^{\ensuremath{-}1}$ for spin-changing collisions within the $F=2$ manifold and spin-dependent loss rates in the range of ${10}^{\ensuremath{-}13}\text{ }\text{ }{\mathrm{c}\mathrm{m}}^{3}\text{ }{\mathrm{s}}^{\ensuremath{-}1}$ for hyperfine-changing collisions. We observe polar behavior in the $F=2$ ground state of $^{87}\mathrm{R}\mathrm{b}$, while we find the $F=1$ ground state to be ferromagnetic. We further see a magnetization for condensates prepared with nonzero total spin.
TL;DR: In this paper, the authors study the quantum dynamics of a number of model systems as their coupling constants are changed rapidly across a quantum critical point, and obtain numerical results on the evolution of the density wave order as the potential gradient is scanned across the quantum critical points.
Abstract: We study the quantum dynamics of a number of model systems as their coupling constants are changed rapidly across a quantum critical point. The primary motivation is provided by the recent experiments of Greiner et al. [Nature (London) 415, 39 (2002)] who studied the response of a Mott insulator of ultracold atoms in an optical lattice to a strong potential gradient. In a previous work, it had been argued that the resonant response observed at a critical potential gradient could be understood by proximity to an Ising quantum critical point describing the onset of density wave order. Here we obtain numerical results on the evolution of the density wave order as the potential gradient is scanned across the quantum critical point. This is supplemented by studies of the integrable quantum Ising spin chain in a transverse field, where we obtain exact results for the evolution of the Ising order correlations under a time-dependent transverse field. We also study the evolution of transverse superfluid order in the three-dimensional case. In all cases, the order parameter is best enhanced in the vicinity of the quantum critical point.
TL;DR: In this paper, the properties of nonlinear higher spin gauge theories of totally symmetric massless higher spin fields in anti-de Sitter space of any dimension are discussed with the emphasize on the general aspects of the approach.
Abstract: Properties of nonlinear higher spin gauge theories of totally symmetric massless higher spin fields in anti-de Sitter space of any dimension are discussed with the emphasize on the general aspects of the approach.
TL;DR: In this paper, high-resolution photo-emission experiments performed with a full three-dimensional spin polarimeter provide a detailed image of the resulting spin structure, showing that the spin vector lies in the surface plane and is perpendicular to the momentum of the electrons as expected in a freeelectron model.
Abstract: The free-electron like surface state on the (111) surface of gold shows a splitting into two parabolic subbands induced by the spin orbit interaction. Spin-resolved high-resolution photoemission experiments performed with a full three-dimensional spin polarimeter provide a detailed image of the resulting spin structure. In particular, spin-resolved momentum distribution maps show that the spin vector lies in the surface plane and is perpendicular to the momentum of the electrons as expected in a free-electron model. This method of measuring the spin structure of a two-dimensional electron gas allows the observation of the direction of electric fields as probed by the electrons. Although the energy splitting can only be understood as a consequence of strong atomic electric fields, no modulation of the spin direction due to these fields is detected.
TL;DR: It is proved that the system possesses a completely integrable point leading to the existence of multiple bright solitons and a collision law for two-soliton solutions is analyzed and found that the dynamics can be explained in terms of the spin precession.
Abstract: We propose an integrable model of a multicomponent spinor Bose-Einstein condensate in one dimension, which allows an exact description of the dynamics of bright solitons with spin degrees of freedom We consider specifically an atomic condensate in the $F=1$ hyperfine state confined by an optical dipole trap When the mean-field interaction is attractive (${c}_{0}l0$) and the spin-exchange interaction of a spinor condensate is ferromagnetic (${c}_{2}l0$), we prove that the system possesses a completely integrable point leading to the existence of multiple bright solitons By applying results from the inverse scattering method, we analyze a collision law for two-soliton solutions and find that the dynamics can be explained in terms of the spin precession
TL;DR: It is conjecture that a local constraint obeyed by the extensively degenerate ground states dictates a dipolar form for the asymptotic spin correlations, at all N not equal 2 for which the system is paramagnetic down to T=0.
Abstract: We study spin correlations for the highly frustrated classical pyrochlore lattice antiferromagnets with $O(N)$ symmetry in the limit $T\ensuremath{\rightarrow}0$. We conjecture that a local constraint obeyed by the extensively degenerate ground states dictates a dipolar form for the asymptotic spin correlations, at all $N\ensuremath{
e}2$ for which the system is paramagnetic down to $T=0$. We verify this conjecture in the cases $N=1$ and $N=3$ by simulations and to all orders in the $1/N$ expansion about the solvable $N=\ensuremath{\infty}$ limit. Remarkably, the $N=\ensuremath{\infty}$ formulas are an excellent fit, at all distances, to the correlators at $N=3$ and even at $N=1$. Thus we obtain a simple analytical expression also for the correlations of the equivalent models of spin ice and cubic water ice, $\mathrm{I}c$.
TL;DR: In this article, the authors show that the domain wall has its maximum velocity at the initial application of the current but the velocity decreases to zero as the wall begins to deform during its motion, and they also introduce the concept of domain wall inductance to characterize the capacity of the spin-torque induced magnetic energy stored in a domain wall.
Abstract: In a first approximation, known as the adiabatic process, the direction of the spin polarization of currents is parallel to the local magnetization vector in a domain wall. Thus the spatial variation of the direction of the spin current inside the domain wall results in an adiabatic spin-transfer torque on the magnetization. We show that domain-wall motion driven by this spin torque has many unique features that do not exist in the conventional wall motion driven by a magnetic field. By analytically and numerically solving the Landau-Lifshitz-Gilbert equation along with the adiabatic spin torque in magnetic nanowires, we find that the domain wall has its maximum velocity at the initial application of the current but the velocity decreases to zero as the domain wall begins to deform during its motion. We have computed domain-wall displacement and domain-wall deformation of nanowires, and concluded that the spin torque based on the adiabatic propagation of the spin current in the domain wall is unable to maintain wall movement. We also introduce the concept of domain-wall inductance to characterize the capacity of the spin-torque-induced magnetic energy stored in a domain wall. In the presence of domain-wall pinning centers, we construct a phase diagram for the domain-wall depinning by the combined action of the magnetic field and the spin current.
TL;DR: The equation-of-motion coupled-cluster methods truncated after double, triple, or quadruple cluster and linear excitation operators have been derived and implemented into parallel execution programs, and knowledge is used to guide the computer-synthesized programs to fully exploit the permutation symmetry of any tensor to minimize the arithmetic and memory costs.
Abstract: The equation-of-motion coupled-cluster (EOM-CC) methods truncated after double, triple, or quadruple cluster and linear excitation operators (EOM-CCSD, EOM-CCSDT, and EOM-CCSDTQ) have been derived and implemented into parallel execution programs. They compute excitation energies, excited-state dipole moments, and transition moments of closed- and open-shell systems, taking advantage of spin, spatial (real Abelian), and permutation symmetries simultaneously and fully (within the spin–orbital formalisms). The related Λ equation solvers for coupled-cluster (CC) methods through and up to connected quadruple excitation (CCSD, CCSDT, and CCSDTQ) have also been developed. These developments have been achieved, by virtue of the algebraic and symbolic manipulation program that automated the formula derivation and implementation altogether. The EOM-CC methods and CC Λ equations introduce a class of second quantized ansatz with a de-excitation operator (Ŷ), a number of excitation operators (X), and a physical (e.g....
TL;DR: An optical lattice setup to investigate spin chains and ladders and ways to measure a number of observables, like energy gap, staggered magnetization, end-chain spins effects, spin correlations, and the string-order parameter are proposed.
Abstract: We propose an optical lattice setup to investigate spin chains and ladders. Electric and magnetic fields allow us to vary at will the coupling constants, producing a variety of quantum phases including the Haldane phase, critical phases, quantum dimers, etc. Numerical simulations are presented showing how ground states can be prepared adiabatically. We also propose ways to measure a number of observables, like energy gap, staggered magnetization, end-chain spins effects, spin correlations, and the string-order parameter.
TL;DR: In this article, the massively parallelized full-potential linearized augmented plane-wave bulk and film program FLEUR for first-principles calculations in the context of density functional theory was adapted to allow calculations of materials with complex magnetic structures.
Abstract: The massively parallelized full-potential linearized augmented plane-wave bulk and film program FLEUR for first-principles calculations in the context of density functional theory was adapted to allow calculations of materials with complex magnetic structures---i.e., with noncollinear spin arrangements and incommensurate spin spirals. The method developed makes no shape approximation to the charge density and works with the continuous vector magnetization density in the interstitial and vacuum region and a collinear magnetization density in the spheres. We give an account of the implementation. Important technical aspects, such as the formulation of a constrained local moment method in a full-potential method that works with a vector magnetization density to deal with specific preselected nonstationary-state spin configurations, the inclusion of the generalized gradient approximation in a noncollinear framework, and the spin-relaxation method are discussed. The significance and validity of different approximations are investigated. We present examples to the various strategies to explore the magnetic ground state, metastable states, and magnetic phase diagrams by relaxation of spin arrangements or by performing calculations for constraint spin configurations to invest the functional dependence of the total energy and magnetic moment with respect to external parameters.
TL;DR: In this article, a study of the low temperature bulk magnetic properties of the spin ice compound with particular attention to the $(Tl4\mathrm{K})$ spin freezing transition was performed.
Abstract: We report a study of the low temperature bulk magnetic properties of the spin ice compound ${\mathrm{Dy}}_{2}{\mathrm{Ti}}_{2}{\mathrm{O}}_{7}$ with particular attention to the $(Tl4\mathrm{K})$ spin freezing transition. While this transition is superficially similar to that in a spin glass, there are important qualitative differences from spin glass behavior: the freezing temperature increases slightly with applied magnetic field, and the distribution of spin relaxation times remains extremely narrow down to the lowest temperatures. Furthermore, the characteristic spin relaxation time increases faster than exponentially down to the lowest temperatures studied. These results indicate that spin-freezing in spin ice materials represents a novel form of magnetic glassiness associated with the unusual nature of geometrical frustration in these materials.
TL;DR: In this paper, the authors use a bond-operator formulation to obtain a continuous description of all disordered and ordered phases, and thus of the transitions separating these, which can be used to explore both types of quantum phase transition and their associated critical phenomena.
Abstract: Thallium copper chloride is a quantum spin liquid of $S=1/2$ ${\mathrm{Cu}}^{2+}$ dimers. Interdimer superexchange interactions give a three-dimensional magnon dispersion and a spin gap significantly smaller than the dimer coupling. This gap is closed by an applied hydrostatic pressure of approximately 2 kbar or by a magnetic field of 5.6 T, offering a unique opportunity to explore both types of quantum phase transition and their associated critical phenomena. We use a bond-operator formulation to obtain a continuous description of all disordered and ordered phases, and thus of the transitions separating these. Both pressure- and field-induced transitions may be considered as the Bose--Einstein condensation of triplet magnon excitations, and the respective phases of staggered magnetic order as linear combinations of dimer-singlet and dimer-triplet modes. We focus on the evolution with applied pressure and field of the magnetic excitations in each phase, and in particular on the gapless (Goldstone) modes in the ordered regimes which correspond to phase fluctuations of the ordered moment. The bond-operator description yields a good account of the magnetization curves and of magnon dispersion relations observed by inelastic neutron scattering under applied fields, and a variety of experimental predictions for pressure-dependent measurements.
TL;DR: In this paper, the authors derived analytic expressions for the reflection and transmission coefficients of the corresponding one-electron scattering problem in the presence of spin-orbit interaction (SOI) of strength and a perpendicular magnetic field.
Abstract: Electron transport through a one-dimensional ring connected with two external leads, in the presence of spin-orbit interaction (SOI) of strength $\ensuremath{\alpha}$ and a perpendicular magnetic field is studied. Applying Griffith's boundary conditions we derive analytic expressions for the reflection and transmission coefficients of the corresponding one-electron scattering problem. We generalize earlier conductance results by Nitta et al. [Appl. Phys. Lett. 75, 695 (1999)] and investigate the influence of $\ensuremath{\alpha},$ temperature, and a weak magnetic field on the conductance. Varying $\ensuremath{\alpha}$ and temperature changes the position of the minima and maxima of the magnetic-field dependent conductance, and it may even convert a maximum into a minimum and vice versa.
TL;DR: Personality constructs were proposed to describe intraindividual variability in interpersonal behavior and flux, pulse, and spin provide reliable and distinctive additions to the vocabulary for describing individual differences.
Abstract: Personality constructs were proposed to describe intraindividual variability in interpersonal behavior. Flux refers to variability about an individual's mean score on an interpersonal dimension and was examined for the 4 poles of the interpersonal circumplex. Pulse and spin refer to variability about an individual's mean extremity and mean angular coordinate on the interpersonal circumplex. These constructs were measured using event-contingent recording. Latent state-trait analyses indicated high stability of flux in submissive, agreeable, and quarrelsome behaviors and some stability in the flux of dominance. Further analyses indicated moderate to high stability in pulse and spin. Neuroticism predicted greater pulse, spin, and submissive behavior flux. Extraversion predicted greater flux in agreeable behavior. In contrast, Agreeableness predicted reduced spin and quarrelsome behavior flux. Social environmental variables predicted greater flux in dominant behavior. Flux, pulse, and spin provide reliable and distinctive additions to the vocabulary for describing individual differences.
TL;DR: In this article, the influence of spin-orbit coupling on the spin susceptibility of superconductors was discussed, with a particular emphasis on the recently discovered heavy Fermion superconductor CePt3Si.
Abstract: In materials without spatial inversion symmetry, the spin degeneracy of the conduction electrons can be lifted by an antisymmetric spin–orbit coupling. We discuss the influence of this spin–orbit coupling on the spin susceptibility of such superconductors, with a particular emphasis on the recently discovered heavy Fermion superconductor CePt3Si. We find that, for this compound (with tetragonal crystal symmetry) irrespective of the pairing symmetry, the stable superconducting phases would give a very weak change of the spin susceptibility for fields along the c-axis and an intermediate reduction for fields in the basal plane. We also comment on the consequences for the paramagnetic limiting in this material.
Journal Article•
TL;DR: In this paper, the authors studied the dynamics of quantum correlations in a class of exactly solvable Ising-type models and analyzed the time evolution of initial Bell states created in a fully polarized background and on the ground state.
Abstract: We study the dynamics of quantum correlations in a class of exactly solvable Ising-type models. We analyze in particular the time evolution of initial Bell states created in a fully polarized background and on the ground state. We find that the pairwise entanglement propagates with a velocity proportional to the reduced interaction for all the four Bell states. Singletlike states are favored during the propagation, in the sense that tripletlike states change their character during the propagation under certain circumstances. Characteristic for the anisotropic models is the instantaneous creation of pairwise entanglement from a fully polarized state; furthermore, the propagation of pairwise entanglement is suppressed in favor of a creation of different types of entanglement. The ``entanglement wave'' evolving from a Bell state on the ground state turns out to be very localized in space time. Our findings agree with a recently formulated conjecture on entanglement sharing; some results are interpreted in terms of this conjecture.