Unusual heat transport in underdoped cuprates

TL;DR

This paper investigates heat transport in underdoped cuprates using the t-J model and fermion-spin theory, revealing a two-band thermal conductivity spectrum with temperature-dependent features consistent with experimental observations.

Contribution

It introduces a novel analysis of thermal conductivity spectra in underdoped cuprates within the t-J model, highlighting the temperature evolution of spectral bands.

Findings

Thermal conductivity spectrum has two bands at low temperatures.

High-energy band shows a weak peak and vanishes at higher temperatures.

Thermal conductivity increases monotonically with temperature.

Abstract

Within the t-J model, the heat transport of the underdoped cuprates is studied based on the fermion-spin theory. It is shown that at low temperatures the energy dependence of the thermal conductivity spectrum consists of two bands. The higher-energy band shows a weak peak, while the low-energy peak is located at a finite energy. This high-energy broad band is severely suppressed with increasing temperatures, and vanishes at higher temperature. It is also shown that the temperature dependence of the thermal conductivity increases monotonously with increasing temperatures, in agreement with experiments.