Finite temperature mobility of a particle coupled to a fermion environment

TL;DR

This paper investigates how a particle's mobility in a one-dimensional fermionic environment varies with temperature and frequency, revealing divergence at integrability and enhanced mobility near non-integrable regimes.

Contribution

It introduces a numerical study of finite temperature and frequency mobility, highlighting the divergence at integrability and the novel use of random matrix theory for analysis.

Findings

Static mobility diverges at integrable point

Enhanced mobility observed away from integrability

Random matrix theory provides new analysis framework

Abstract

We study numerically the finite temperature and frequency mobility of a particle coupled by a local interaction to a system of spinless fermions in one dimension. We find that when the model is integrable (particle mass equal to the mass of fermions) the static mobility diverges. Further, an enhanced mobility is observed over a finite parameter range away from the integrable point. We present a novel analysis of the finite temperature static mobility based on a random matrix theory description of the many-body Hamiltonian.