Generalization of Luttinger's Theorem for Strongly Correlated Electron Systems

TL;DR

This paper generalizes Luttinger's theorem for strongly correlated electron systems, demonstrating that the Fermi surface volume relates to quasiparticle spectral weight, validated through Hubbard and t-J models.

Contribution

It introduces a generalized form of Luttinger's theorem applicable to strongly correlated systems, accounting for spectral weight of quasiparticles.

Findings

Generalized Luttinger's theorem holds for Hubbard and t-J models.

Fermi surface volume relates to quasiparticle spectral weight.

The theorem is valid in the paramagnetic nonsuperconducting phase.

Abstract

Analyzing general structure of the Green function of a strongly correlated electron system we have shown that for the regime of strong correlations Luttinger's theorem should be generalized in the following way: the volume of the Fermi surface of the system of noninteracting particles is equal to volume of the Fermi surface of the quasiparticles in the strongly correlated system with account for the spectral weight of these quasiparticles. Hubbard and t-J models analysis in the paramagnetic nonsuperconducting phase shows that the generalized Luttinger's theorem is valid for these models.