Low Temperature Transport Properties of Strongly Interacting Systems- Thermal Conductivity of Spin-1/2 Chains

TL;DR

This paper presents a method to compute low-temperature transport properties of strongly interacting systems, specifically thermal conductivity in spin-1/2 chains, using a memory matrix formalism that aligns well with experimental data.

Contribution

It introduces a general approach leveraging fixed point and irrelevant operators to calculate transport properties via memory matrix formalism for interacting systems.

Findings

Good agreement with experimental thermal conductivity data

Effective calculation method for low-temperature transport in spin chains

Applicable to systems with known fixed points and irrelevant operators

Abstract

We outline a general approach to the computation of transport properties of interacting systems at low temperetures and frequencies. We show that if the fixed point and the irrelevant operators around it are known, then by studying the structure of the softly violated conserved currents chracterizing the fixed point one may set up an effective calculation in terms of a memory matrix formalism. We apply this approach to the computation of thermal conductivity of spin chains embedded in a matter matrix and interacting with its phonons. The results are found to be in very good agreement with experiment.