High temperature thermal conductivity of 2-leg spin-1/2 ladders

TL;DR

This paper investigates the high-temperature thermal conductivity of spin-1/2 ladders using numerical methods, revealing unconventional low-frequency behavior and implications for magnetic energy transport in quasi-one-dimensional materials.

Contribution

It introduces a novel Lanczos technique for analyzing thermal conductivity spectra in spin ladders, providing new insights into their frequency-dependent behavior.

Findings

Non-diverging dc thermal conductivity limit

Unconventional low-frequency spectral behavior

Magnetic contributions significantly affect energy transport

Abstract

Based on numerical simulations, a study of the high temperature, finite frequency, thermal conductivity $\kappa(\omega)$ of spin-1/2 ladders is presented. The exact diagonalization and a novel Lanczos technique are employed.The conductivity spectra, analyzed as a function of rung coupling, point to a non-diverging $dc-$limit but to an unconventional low frequency behavior. The results are discussed with perspective recent experiments indicating a significant magnetic contribution to the energy transport in quasi-one dimensional compounds.