Optical conductivity associated with solitons in the Peierls state as modified by zero-point-motion disorder

TL;DR

This paper investigates how quantum lattice fluctuations and static disorder influence the optical conductivity and density of states in Peierls systems with solitons, revealing universal scaling behaviors and the dominant effects on conductivity edges.

Contribution

It extends previous models to include quantum lattice fluctuations as static disorder, demonstrating universal scaling forms and the differing roles of disorder and matrix elements in conductivity edges.

Findings

Soliton density of states and conductivity edges follow universal scaling forms.

Disorder dominates the leading edge of conductivity, while matrix effects influence the trailing edge.

The soliton-to-band conductivity's leading edge aligns with the joint density of states.

Abstract

We extend previous work to consider the effect of the soliton on the density of states and conductivity of quasi-one-dimensional Peierls systems with quantum lattice fluctuations, modeled by a random static disorder. Two features have been verified over an order of magnitude variation in the disorder. (1) The soliton density of states and the leading edges of both the soliton-to-band and the band-to-band conductivities have universal scaling forms. (2) The soliton-to-band conductivity has the remarkable feature that the leading edge is accurately predicted by the joint density of states while the trailing edge tracks the rigid-lattice conductivity. Or, in other words, disorder dominates the leading edge, while matrix element effects are predominant for the trailing edge.