Electric-current–induced heat generation in a quantum dot coupled to a normal and a superconducting lead

¹ Institute of Theoretical Physics, Shanxi University - Taiyuan 030006, China
² Institute of Solid State Physics, Shanxi Datong University - Datong 037009, China

^(a) nieyh@sxu.edu.cn

Received: 2 December 2012
Accepted: 8 February 2013

Abstract

We theoretically study the heat generation induced by the electric current in a quantum dot coupled to a normal and a superconducting lead with weak dot-leads coupling. We find that the heat generation presents quite different properties from the current and can be controlled by the gate voltage, bias and temperature. At zero temperature, there are many ideal regions for device operation with large electric current and small heat generation. Interestingly, at high temperature, the heat generation can become negative in the regions where the phonon-assisted Andreev tunneling and phonon-assisted direct tunneling with absorbing a phonon can occur. This means such a device can serve as a refrigerator.