Field-induced thermal metal-to-insulator transition in underdoped LSCO

TL;DR

This study reveals a unique thermal metal-to-insulator transition in underdoped LSCO induced by magnetic fields, contrasting with behavior in other superconductors, highlighting novel thermal transport phenomena in cuprates.

Contribution

It demonstrates a field-induced thermal metal-to-insulator transition in underdoped LSCO, a phenomenon not observed in other superconductors, advancing understanding of thermal transport in cuprates.

Findings

Thermal conductivity decreases with magnetic field at low temperatures in underdoped LSCO.

A thermal metal-to-insulator transition occurs upon suppression of superconductivity by magnetic field.

Contrasts with increased thermal conductivity in other superconductors under magnetic fields.

Abstract

The transport of heat and charge in cuprates was measured in undoped and heavily-underdoped single crystal La_{2-x}Sr_xCuO_{4+delta} (LSCO). In underdoped LSCO, the thermal conductivity is found to decrease with increasing magnetic field in the T --> 0 limit, in striking contrast to the increase observed in all superconductors, including cuprates at higher doping. The suppression of superconductivity with magnetic field shows that a novel thermal metal-to-insulator transition occurs upon going from the superconducting state to the field-induced normal state.