On the basis of the Kadanoff-Baym (KB) version of the time-dependent Green's function method, an Ansatz for the approximation of a spectral function is offered. The Ansatz possesses all the advantages of quasiparticle and extended quasiparticle approximations and satisfies the KB equation for a spectral function in the case of slightly nonequilibrium system when disturbances in space and time are taken into consideration in the gradient approximation. This feature opens opportunities for the microscopic derivation of the Landau kinetic equation for the quasiparticle distribution function of the normal Fermi liquid and provides the widening of these equations' temperature range of validity.On the basis of the Kadanoff-Baym (KB) version of the time-dependent Green's function method, an Ansatz for the approximation of a spectral function is offered. The Ansatz possesses all the advantages of quasiparticle and extended quasiparticle approximations and satisfies the KB equation for a spectral function in the case of slightly nonequilibrium system when disturbances in space and time are taken into consideration in the gradient approximation. This feature opens opportunities for the microscopic derivation of the Landau kinetic equation for the quasiparticle distribution function of the normal Fermi liquid and provides the widening of these equations' temperature range of validity.

arXiv:cond-mat/0701292Physical Review BAug 17, 20075 citations

Transport Phenomena in Fermi Liquids

Amiram Ron

The phenomenological theory of a Fermi liquid is generalized to nonequilibrium conditions. Landau's theory is reformulated to include fluctuations of the distribution function and quasiparticle energy. The method of fluctuation in kinetic equations is used to establish the collision integral of the quasiparticle Boltzmann equation. This collision integral is expressed in terms of the parameters of Landau's theory, and includes dynamic screening effects. The results are compared with recent theories of transport in Fermi liquids.The phenomenological theory of a Fermi liquid is generalized to nonequilibrium conditions. Landau's theory is reformulated to include fluctuations of the distribution function and quasiparticle energy. The method of fluctuation in kinetic equations is used to establish the collision integral of the quasiparticle Boltzmann equation. This collision integral is expressed in terms of the parameters of Landau's theory, and includes dynamic screening effects. The results are compared with recent theories of transport in Fermi liquids.

Physical Review AApr 1, 19701 citation

Numerical calculations of quasiparticle dynamics in a Fermi liquid

Timo H. Virtanen

Jan 1, 20110 citations

Spectral function of two-dimensional Fermi liquids

Christoph J. Halboth, Walter Metzner

We show that the spectral function for single-particle excitations in a two-dimensional Fermi liquid has a Lorentzian shape in the low-energy limit. Landau quasiparticles have a uniquely defined spectral weight and a decay rate which is much smaller than the quasiparticle energy. By contrast, perturbation theory and the $T$ -matrix approximation yield spurious deviations from Fermi-liquid behavior, which are particularly pronounced for a linearized dispersion relation.We show that the spectral function for single-particle excitations in a two-dimensional Fermi liquid has a Lorentzian shape in the low-energy limit. Landau quasiparticles have a uniquely defined spectral weight and a decay rate which is much smaller than the quasiparticle energy. By contrast, perturbation theory and the $T$-matrix approximation yield spurious deviations from Fermi-liquid behavior, which are particularly pronounced for a linearized dispersion relation.

arXiv:cond-mat/9706143Physical review. B, Condensed matterApr 15, 199817 citations

T

-matrix approximation yield spurious deviations from Fermi-liquid behavior, which are particularly pronounced for a linearized dispersion relation.