Heat Coulomb blockade in a double-island metal-semiconductor device

TL;DR

This paper investigates heat Coulomb blockade in a double-island mesoscopic device within the quantum Hall regime, revealing unique suppression effects and conditions for Wiedemann-Franz law violation.

Contribution

It introduces a novel analysis of heat transport in a double-island system, highlighting the role of multiple edge channels and predicting new suppression phenomena.

Findings

Heat flux reduction by a quantum of thermal conductance in single-island case.

Additional suppression proportional to M^2/(2N+M)^2 in double-island systems.

Conditions for Wiedemann-Franz law violation identified.

Abstract

We study the thermal transport properties of a mesoscopic device comprising two metallic islands embedded in a two-dimensional electron gas in the integer quantum Hall regime. It is shown that the $2M$ ballistic edge channels connecting the islands to the external reservoirs and the $N$ inter-island channels play a central role in the phenomenon of heat Coulomb blockade. Unlike the single-island case, where the heat flux is reduced by exactly one quantum of thermal conductance, we predict an additional suppression proportional to the factor $M^2/(2N+M)^2$. We further examine a configuration in which the islands are placed between electrodes at different temperatures and identify the conditions under which the Wiedemann-Franz law is violated.