Electron liquid state in the spin-1/2 anisotropic Kondo lattice

TL;DR

This paper presents an analytical and numerical mean field solution for the spin-1/2 anisotropic Kondo lattice, revealing a gapped electron liquid state with a large Fermi surface and static local moments, applicable across various dimensions.

Contribution

It introduces a mean field approach to analyze the anisotropic Kondo lattice, providing insights into the electron spectrum and ground state structure for arbitrary dimensions.

Findings

A gap opens in the fermion spectrum due to local moment fields.

The ground state features a static Z_2 field of local moments forming a double cell lattice.

A large Fermi surface emerges from hybridization between electron states.

Abstract

In the framework of the mean field approach, we provide analytical and numerical solution of the spin-1/2 anisotropic Kondo lattice for arbitrary dimension at half filling. Nontrivial solution for the amplitude of the field opens a gap in the fermion spectrum of an electron liquid in which local moments on the lattice sites are realized. The ground state in the insulator state is determined by a static Z_2 field of local moments, which forms the lattice with a double cell, conduction electrons move in this field. Due to hybridization between electron states a large Fermi surface is formed in the Kondo lattice. A gap in the quasi-particle spectrum is calculated depending on the magnitudes of exchange integrals for the simple lattices with different dimension. The proposed approach is also valid for describing the Kondo lattice with weak anisotropy of the exchange interaction, which makes it possible to study the behavior of the spin-1/2 Kondo lattice with an isotropic exchange interaction.