Regular Article

Three-terminal normal-superconductor junction as thermal transistor

¹ Department of Physics, National University of Singapore, Singapore 117551, Republic of Singapore
² Center for Phononics and Thermal Energy Science, China-EU Joint Center for Nanophononics, Shanghai Key Laboratory of Special Artificial Microstructure Materials and Technology, School of Physics Science and Engineering, Tongji University, 200092 Shanghai, P.R. China

^a e-mail: gmtang1212@gmail.com

Received: 22 December 2018
Received in final form: 31 December 2018
Published online: 4 February 2019

Abstract

We propose a thermal transistor based on a three-terminal normal-superconductor junction with superconductor terminal acting as the base. The emergence of heat amplification is due to the negative differential thermal conductance (NDTC) effect for the NS diode in which the normal side maintains a higher temperature. The temperature dependent superconducting energy gap is responsible for the NDTC. By controlling quantum dot levels and their coupling strengths to the terminals, a huge heat amplification factor can be achieved. The setup offers an alternative tuning scheme of heat amplification factor and may find use in cryogenic applications.