Thermal properties of the superconductor-quantum Hall interfaces

TL;DR

This study investigates the thermal behavior at superconductor-quantum Hall interfaces, revealing significant electronic heat transport likely due to vortex core states, which contrasts with conventional expectations.

Contribution

It provides the first experimental evidence of electronic heat conductivity at superconductor-quantum Hall interfaces, highlighting the role of vortex core states in thermal transport.

Findings

Superconductor provides significant thermal conductivity linear in temperature.

Thermal noise measurement reveals local electron temperature increase.

Electronic heat transport attributed to vortex core states.

Abstract

An important route of engineering topological states and excitations is to combine superconductors (SC) with the quantum Hall (QH) effect, and over the past decade, significant progress has been made in this direction. While typical measurements of these states focus on electronic properties, little attention has been paid to the accompanying thermal responses. Here, we examine the thermal properties of the interface between a type-II superconducting electrodes and graphene in the QH regime. We use the thermal noise measurement to probe the local electron temperature of the biased interface. Surprisingly, the measured temperature raise indicates that the superconductor provides a significant thermal conductivity, which is linear in temperature. This suggests electronic heat transport and may be unexpected, because the number of the quasiparticles in the superconductor should be exponentially suppressed. Instead, we attribute the measured electronic heat conductivity to the overlap of the normal states in the vortex cores.