Thermopower generation and thermoelectric cooling in a Kane-Mele normal-insulator-superconductor nano-junction

Indian Institute of Technology Guwahati - Assam-781039, India

Received: 24 November 2018
Accepted: 12 February 2019

Abstract

We have studied the thermoelectric effect of a Kane-Mele normal-insulator-superconductor (KMNIS) junction at low temperatures using a modified version of the Blonder-Tinkham-Klapwijk (BTK) theory. Since both the (electronic) charge and thermal current due to the carriers are sensitive to the strengths of the spin-orbit coupling (SOC) present in the Kane-Mele model, a tunability of this junction device with regard to its thermoelectric properties can be experimentally achieved by certain techniques that are used to manipulate the values of the spin-orbit couplings. We have computed the Seebeck coefficient, figure of merit, thermoelectric cooling, coefficient of performance of the KMNIS junction as a self-cooling device and investigated the role of the Rashba SOC (RSOC) and intrinsic SOC (ISOC) parameters therein. Our results on the thermoelectric cooling indicate the practical realizability and usefulness for efficient cooling detectors, sensors, and quantum devices and hence could be crucial to the experimental success of the thermoelectric applications of such junction devices. Further we have briefly touched upon the condition that possibly distinguishes the transmission through a topological insulator from an ordinary one.