Fractionalized Fermi liquids

TL;DR

This paper explores fractionalized Fermi liquid states in Kondo lattice models, revealing novel non-magnetic phases with fractionalized excitations, distinct Fermi surface volumes, and phase transitions influenced by gauge theories.

Contribution

It introduces the concept of FL* states with fractionalized excitations and distinct Fermi surface volumes, expanding understanding of non-magnetic phases in Kondo lattice models.

Findings

FL* states have a Fermi surface volume quantized by ( ho_a-1)(mod 2).

Confinement transitions lead to conventional Fermi liquids or superconducting states.

FL* states allow second order metamagnetic transitions under magnetic fields.

Abstract

In spatial dimensions d >= 2, Kondo lattice models of conduction and local moment electrons can exhibit a fractionalized, non-magnetic state (FL*) with a Fermi surface of sharp electron-like quasiparticles, enclosing a volume quantized by (\rho_a-1)(mod 2), with \rho_a the mean number of all electrons per unit cell of the ground state. Such states have fractionalized excitations linked to the deconfined phase of a gauge theory. Confinement leads to a conventional Fermi liquid state, with a Fermi volume quantized by \rho_a (mod 2), and an intermediate superconducting state for the Z_2 gauge case. The FL* state permits a second order metamagnetic transition in an applied magnetic field.