Nonlocal optical conductivity of Fermi surface nesting materials

TL;DR

This paper explores the nonlocal optical conductivity in Fermi surface nesting materials, revealing how doping induces half-metal states and how nonlocal effects modify the optical response.

Contribution

It introduces a model for nonlocal optical conductivity in nesting materials and links doping-induced phases to observable optical features.

Findings

Drude peak shifts to higher frequency in nonlocal conductivity

Splitting of the Drude peak into two peaks due to different Fermi velocities

Doping leads to half-metal and spin-valley half-metal states

Abstract

We investigate the nonlocal optical conductivity of Fermi surface nesting materials which support charge density waves or spin density waves. The nonlocal optical conductivity contains information of correlations in electron fluids which could not be accessed by standard optical probes. Half metal emerges from doping a charge density wave and similarly spin-valley half metal emerges from doping a spin density wave. Based on the parabolic band approximation, we find the Drude peak is shifted to higher frequency and splits into two peaks in the nonlocal optical conductivity. We attribute this to the two Fermi velocities in the half-metal or spin-valley half metal states.