Thermal and Electrical Currents in Nanoscale Electronic Interferometers

TL;DR

This paper theoretically investigates thermal and electrical transport in a nanoscale electronic interferometer with quantum dots, revealing quantum interference effects that cause heat currents to flow counterintuitively and induce magnetic polarization.

Contribution

It introduces a model of a quantum dot interferometer demonstrating heat currents flowing against the temperature gradient due to quantum interference effects.

Findings

Heat current can flow from cold to hot locally.

Global entropy production remains positive, respecting thermodynamics.

Electrical currents induce magnetic polarization.

Abstract

We theoretically study thermal transport in an electronic interferometer comprising a parallel circuit of two quantum dots, each of which has a tunable single electronic state which are connected to two leads at different temperature.As a result of quantum interference, the heat current through one of the dots is in the opposite direction to the temperature gradient. An excess heat current flows through the other dot. Although locally, heat flows from cold to hot, globally the second law of thermodynamics is not violated because the entropy production associated with heat transfer through the whole device is still positive. The temperature gradient also induces a circulating electrical current, which makes the interferometer magnetically polarized.