Showing papers on "Fermi liquid theory published in 1983"
TL;DR: In this article, the exact thermodynamic equations of the Coqblin-Schrieffer model were solved in the scaling regime and the impurity susceptibility and specific heat curves were obtained as a function of temperature for zero field and for impurity spin.
Abstract: The exact thermodynamic equations of the Coqblin-Schrieffer model are solved in the scaling regime and the impurity susceptibility and specific-heat curves are obtained as a function of temperature for zero field and for the impurity spin $J=\frac{1}{2},\dots{},\frac{7}{2}$. The strong dependences of the numerical results on the impurity spin are discussed in terms of a noninteracting Fermi-liquid model.
386 citations
TL;DR: In this paper, a functional integral approach to the Coqblin-Schreiffer Hamiltonian was employed, similar to that of Yoshimori and Sakurai (YS-1970) for the Kondo Hamiltonian, except that a field lambda enforcing the constraint nf=1 is introduced.
Abstract: The authors employ a functional integral approach to the Coqblin-Schreiffer Hamiltonian, similar to that of Yoshimori and Sakurai (YS-1970) for the Kondo Hamiltonian, except that a field lambda enforcing the constraint nf=1 is introduced. By a gauge transformation they show that the phase of the complex sigma field introduced by YS may be absorbed into lambda , leading to a new two-field formulation in terms of lambda and s= mod sigma mod . The static approximation leads to a simple Friedel resonance on the impurity of width approximately TK/N, where N=2J+1 is the number of channels, and whose position is determined by the Friedel sum rule, as in the 'local Fermi liquid' theory. The authors show that the charge susceptibility is zero, is required. Gaussian fluctuation corrections to the static approximation are determined' taking account of fermion propagator renormalisation they then find that the Wilson chi / gamma ratio R=N/(N-1) is correct to order 1/N2. The value of TK is that of a lowest-order renormalisation group treatment, but may be corrected by fluctuation effects.
360 citations
TL;DR: In this paper, laboratory observations with the latest generation of nuclear accelerators are used to infer the surface tension of the liquid-gas interface in nuclear matter, an essential ingredient of the equation of state for which a reliable theoretical model is not available.
Abstract: Every self-bound Fermi liquid will exhibit a liquid–gas phase equilibrium at low temperatures, because the pressure is positive at low densities due to the kinetic energy of degeneracy, and falls to zero again at the equilibrium density. Nuclear matter is seldom found under conditions of two-phase equilibrium, however: in usual nuclear reactions, a heated (‘compound’) nucleus is produced out of equilibrium with its surroundings, which are at a much lower temperature. The most familiar example of a two-phase equilibrium occurs in the crust of neutron stars inside the neutron-drip line1, at temperatures of less than an MeV. In supernovas, in the crucial moments when the implosion is reversed to an explosion, densities comparable to those of neutron stars may be attained with associated temperatures of 5 to 10 MeV. An accurate knowledge of the properties of nuclear matter under these conditions is essential to the understanding of supernova dynamics2. This communication shows how laboratory observations with the latest generation of nuclear accelerators can be used to infer the surface tension of the liquid–gas interface in nuclear matter–an essential ingredient of the equation of state for which a reliable theoretical model is not available.
164 citations
TL;DR: In this article, the influence of the strong interaction between the electrons on the thermodynamic and transport properties of disordered metals is considered and the contributions of the interaction in the diffusion channel to all of the quantities are shown to depend on only one Fermi-liquid interaction constant.
143 citations
TL;DR: In this article, a discussion de l'apparition possible de la superfluidite dans un systeme de fermi dilue degenere, avec un etat lie dimere.
Abstract: Discussion de l'apparition possible de la superfluidite dans un systeme de fermi dilue degenere, avec un etat lie dimere
134 citations
TL;DR: In this article, an orthorhombic CeNi compound was shown to behave as an enhanced Pauli paramagnet in which the magnetic susceptibility along the c axis passes through a maximum at around 140 K.
Abstract: Lattice parameter analysis and studies of thermal expansion show that the orthorhombic CeNi compound is, like CeSn 3 , an intermediate valence compound in which the cerium valence state varies from 3.5 to 3.3 between 4 and 300 K. This compound behaves as an enhanced Pauli paramagnet in which the magnetic susceptibility along the c axis passes through a maximum at around 140 K. Magnetic susceptibility, resistivity and heat capacity measurements are characteristic of an almost magnetic Fermi liquid in which spin fluctuations are present. Unlike the other cerium intermediate valence compounds which are generally cubic, large anisotropic effects due to the local surroundings are observed in CeNi because of its orthorhombic symmetry. All these properties can be understood in the light of the band structure of this type of alloy in which a large hybridization occurs between the Ni 3d electrons and the Ce 5d electrons.
99 citations
TL;DR: A review of the paramagnon model and other phenomenological models for liquid 3 He and their relationship to Landau Fermi liquid theory is given in this paper, where a comparison with experiment at different pressures for the neutron cross section, the superfluid transition temperature, the specific heat discontinuities at the liquid phase boundary and transport properties are discussed at length.
39 citations
TL;DR: In this article, exact results for the slip length and surface impedance of a superfluid Fermi liquid were derived for the case of diffuse boundary scattering and compared with previous approximate results based on variational methods.
Abstract: Exact results for the slip length and the surface impedance of a superfluid Fermi liquid are reported for the case of diffuse boundary scattering and compared with previous approximate results based on variational methods. We also derive upper and lower bounds on the slip length for a general class of scattering laws, including the case of Andreev reflection due to suppression of the order parameter near the walls.
37 citations
TL;DR: In this article, exact results for the transport coefficients of a highly degenerate spin-polarized Fermi system are presented for weakly interacting particles, such as dilute3He in4He or D ↓, and corrections as large as 8% are found.
Abstract: Exact results for the transport coefficients of a highly degenerate spin-polarized Fermi system are presented. The case of weakly interacting particles, such as dilute3He in4He or D ↓, is treated. The results are compared to the variational treatment and corrections as large as 8% are found. Detailed behavior of the polarization of an ideal Fermi gas as a function of temperature and magnetic field is discussed as a model for dilute3He in4He. Limits of applicability of the formulas are given. We find that at appropriate fields and temperatures, the two spin species may be considered to be a mixture of a degenerate and a classical gas.
36 citations
34 citations
TL;DR: In this paper, a model for paramagnetic Fermi liquids has been developed, which has both direct and induced interactions, the latter including both density-density and current-current response, and is applied in detail to liquid3He, using data from spin-echo experiments, sound attenuation, and the velocities of first and zero sound.
Abstract: We develop a model for paramagnetic Fermi liquids. This model has both direct and induced interactions, the latter including both density-density and current-current response. The direct interactions are chosen to reproduce the Fermi liquid parametersF
0
s
,F
0
a
,F
1
s
and to satisfy the forward scattering sum rule. TheF
1
a
andF
1
s,a
for1>1 are determined self-consistently by the induced interactions; they are checked against experimental determinations. The model is applied in detail to liquid3He, using data from spin-echo experiments, sound attenuation, and the velocities of first and zero sound. Consistency with experiments gives definite preferences for values ofm*. The model is also applied to paramagnetic metals. Arguments are given that this model should provide a basis for calculating effects of magnetic fields.
TL;DR: In this article, the Fermi surface properties of the coherent and incoherent forms of the dense Kondo and mixed valence models for anomalous Ce compounds are examined, and the experimental results for CeSn 3 and its isostructrural, non-4f analog LaSn 3 are presented and found to be consistent with either a coherent mixed value or Kondo lattice interpretation.
TL;DR: In this paper, the Bethe-ansatz equations describing the thermodynamics of the non-degenerate Anderson model were derived in the U→∞ limit (double occupation of the localized level is excluded).
Abstract: The Bethe-ansatz equations describing the thermodynamics of the non-degenerate Anderson model are derived in theU→∞ limit (double occupation of the localized level is excluded). The set of Bethe-ansatz equations for theU→∞ limit is considerably different from the one for the finiteU case. The Kondo limit, the Fermi liquid behavior at lowT and the highT perturbation expansion for the thermodynamic potential are extracted from these equations.
TL;DR: In this paper, the spin diffusion, spin thermodiffusion, and spin bulk viscosity coefficients for spin-polarized Fermi liquids and gaseous mixtures were investigated.
Abstract: Transport phenomena in spin-polarized3He systems are studied (normal Fermi liquid3He↑,3He↑-He II solutions, gas3He↑,3He↑-4He gaseous mixtures). The transport coefficients, including the spin diffusion, spin thermodiffusion, and spin bulk viscosity coefficients, are calculated for spinpolarized Fermi liquids and gaseous mixtures. The analogy of the “spin rotation effect” in polarized nondegenerate gases with similar phenomena in degenerate Fermi systems and with collisionless spin oscillations is discussed.
TL;DR: In this article, specific heat and magnetic susceptibility of the periodic Anderson Hamiltonian were discussed on the basis of the microscopic Fermi liquid theory, and it was pointed out that the Wilson ratio in the periodic system can take values over a different range from that of a single impurity system.
TL;DR: In this article, the reflection of wave packets of quasiparticles from surfaces of a superfluid Fermi liquid is studied, and the reflection process is accompanied by changes in the internal structure of the wave packet.
Abstract: We study the reflection of wave packets of quasiparticles from surfaces of a superfluid Fermi liquid. The reflection process is accompanied by changes in the internal structure of the wave packet. One finds particle-hole conversion (Andreev reflection), and a changed magnetization of the wave packet. The latter effect is a special consequence of triplet pairing and is related to the spontaneously broken spin-orbit symmetry. A particularly striking example is a non-magnetic wave packet that is split by the surface into two magnetic ones moving in different directions.
TL;DR: In this article, heat transfer between normal liquid 3He and sintered powders is investigated in terms of the Landau Fermi liquid theory, and it is shown that the coupling between zero sound and low energy vibrational modes in sinter gives the extra contribution to the heat transfer below about 10mK.
TL;DR: In this article, the spin-diffusion coefficient of a polarized two-dimensional degenerate Fermi fluid is evaluated as a model of adsorbed $^{3}\mathrm{He}.
Abstract: The spin-diffusion coefficient $D$ of a polarized two-dimensional degenerate Fermi fluid is evaluated as a model of adsorbed $^{3}\mathrm{He}$. Because in two dimensions, for zero or weak polarization, the only allowed scattering angles are 0 and $\ensuremath{\pi}$, the transport coefficients become expressible in terms of Landau parameters without approximation. For unpolarized and weakly polarized systems it is shown that ${D}^{\ensuremath{-}1}\ensuremath{\sim}{T}^{2}\mathrm{ln}T$ and ${T}^{2}\mathrm{ln}(\mathrm{polarization})$, respectively. The two-dimensional kinetic equation is found to be exactly solvable.
TL;DR: In this article, the Fermi contact term of the nuclear-spin-spin coupling in the HD molecule is calculated using finite-field many-body perturbation theory (FF MBPT).
Abstract: The Fermi contact term of the nuclear-spin---spin coupling in the HD molecule is calculated using finite-field many-body perturbation theory (FF MBPT). The one-electron states are generated by the Hartree-Fock potential in the presence of the Fermi contact interaction. The procedure through third order in electron correlation gives a value for the Fermi contact term of 37.2 Hz in fair agreement with the best estimated value of 40.0 Hz at the equilibrium internuclear distance. The result suggests that the FF MBPT approach provides a highly efficient and systematic method for the calculation of the Fermi contact term. A possible origin of the general overestimate by the coupled Hartree-Fock method is also discussed.
TL;DR: The development of the Fermi surface from its theoretical origins to its experimental determination over a period of nearly 30 years is described in this paper, where the authors trace the evolution of the concept from theoretical to experimental determination.
Abstract: The article traces the development of the concept of the Fermi Surface from its theoretical origins to its experimental determination over a period of nearly 30 years.
TL;DR: In this article, the amplitude of the moment, estimated by integrating of observed response over an inverse atomic volume, was found not to vary significantly with temperature, and a quantitative interpretation of these results was given in terms of a model in which FeSi shows properties of a heavy Fermi liquid.
TL;DR: In this article, a detailed investigation of the effective mass and g-factor of conduction electrons in cesium was made, and a mass anisotropy of 21.6% was observed about a Fermi surface (FS) average value ofm*/mo=1.447±0.02.
Abstract: Using the de Haas-van Alphen (dHvA) effect, we have made a detailed investigation of the effective mass and g-factor of conduction electrons in cesium. A mass anisotropy of 21.6% is observed about a Fermi surface (FS) average value ofm*/mo=1.447±0.02. The g-factor, derived in a variety of ways, has a mean value 2.96±0.03, with little if any orientational variation. These results yield a spin susceptibility 2.14±0.01 times the free-electron value, and a Fermi liquid parameterBo=−0.322±0.007. When all factors including FS topography, temperature, electron scattering, spin splitting, and effective mass are taken into account, the marked amplitude variation of the dHvA effect with orientation is described rather exactly. The results are compared with recent many-body calculations.
TL;DR: In this paper, a description of the concentration dependence of the magnetic susceptibilities of a number of liquid binary alloys of simple metals is effected in three stages: first, a previous pseudopotential formalism is extended to enable the calculation of the conduction electron diamagnetic susceptibilities in the pure liquid metals, Li, Na, K, Rb, Cs, In and Pb.
Abstract: A description of the concentration dependence of the magnetic susceptibilities of a number of liquid binary alloys of simple metals is effected in three stages. First, a previous pseudopotential formalism is extended to enable the calculation of the conduction electron diamagnetic susceptibilities in the pure liquid metals, Li, Na, K, Rb, Cs, In and Pb. These results are then combined with much earlier calculated values of the diamagnetic susceptibilities of the core electrons and with observed values, existing in the literature, of the total magnetic susceptibilities to infer the conduction electron paramagnetic susceptibilities of the above pure liquid metals. Second, the expressions for the two diamagnetic contributions are modified permitting the determination of their concentration dependence in a number of nearly-free-electron (NFE) like liquid binary alloys. The Landau theory of a Fermi liquid is used to infer the concentration dependence of the paramagnetic contribution. Third, Li-Pb, which is not NFE like over the entire concentration range is treated separately as a special but closely related case. The observed results for the concentration dependence of the total magnetic susceptibility are favourably reproduced, both for those alloy systems exhibiting smooth variations and for those with large variations.
KEK1
TL;DR: In this paper, the dispersion law of sound propagation in the degenerate Fermi liquid was studied and the damped oscillation mode (Landau damping) due to quantum effects was found.
TL;DR: In this paper, an exact equivalence of the periodic Anderson model and generalized Hubbard model in atomic representation is shown, and the energy spectrum of the quasiparticle is calculated by using diagram technique for the Hubbard operators.
TL;DR: In this article, the effects of Fermi liquid parameters on upper critical field H c2 are discussed theoretically and the Maki parameter which characterizes behavior of H c 2 in the presence of the Pauli paramagnetic effect is found to be renormalized by electron-electron interaction.
Abstract: Effects of Fermi liquid parameters on upper critical field H c2 are discussed theoretically. The Maki parameter which characterizes behavior of H c2 in the presence of the Pauli paramagnetic effect is found to be renormalized by electron-electron interaction. Experimental data on a “heavy Fermion” superconductor CeCu 2 Si 2 are analyzed.
TL;DR: The velocity of sound for polarized Fermi liquids at frequencies intermediate between the inverse spin relaxation time and the inverse typical relaxation time was found via the kinetic equation as discussed by the authors, which is not expressed by the static compressibility at a fixed magnetic field but at fixed spin polarization.
01 Jan 1983
TL;DR: In this article, the authors consider mostly 3D transition metals and some actinide systems where spin-orbit coupling may be neglected for most purposes, and they show that the magnetic moments themselves are not associated with localized electrons.
Abstract: In magnetic insulators the magnetic moments are associated with localized electrons which interact magnetically through the mechanism of superexchange. In the case of normal rare-earth metals, of integral valence, a rather similar situation exists. However now the magnetic interaction between the localized 4f electrons takes place through a spin polarization of the conduction band so that itinerant electrons play a role. In magnetic transition metals and some actinide systems the 3d and 5f electrons are itinerant, so that the magnetic moments themselves are not associated with localized electrons. Characteristic properties of such systems are non-integral saturation moments, large electronic specific heat, and the existence of d- or f-like parts of the Fermi surface which may be observed directly by de Haas-van Alphen measurements. Clearly any theory of magnetism in the transition metals must be founded in band theory. In these lectures we shall consider mostly 3d transition metals where spin-orbit coupling may be neglected for most purposes. This is certainly not the case in actinide materials.