Anisotropic Andreev reflection across a borophane-based superconducting junction

¹ School of Electronic and Information Engineering, Jinling Institute of Technology - Nanjing, 211169, China
² New Energy Technology Engineering Laboratory of Jiangsu Province, School of Science, Nanjing University of Posts and Telecommunications - Nanjing, 210023, China

^(a) zxf@njupt.edu.cn (corresponding author)

Received: 28 February 2020
Accepted: 17 April 2020

Abstract

We investigate the Andreev reflection across a borophane-based superconducting junction in different directions of junction. There are three exotic properties which are different from the ones in graphene. Firstly, the Andreev retro-reflection happens in the interband conversion of electron-hole. Secondly, the electron-hole conversion in the intraband leads to the specular Andreev reflection. Thirdly, the perfect Andreev reflection, the electron-hole conversion with unit efficiency, happens at a nonzero incident angle of electron. These three unique properties arise from the anisotropic band structure of borophane and can be modulated by adjusting the direction of junction. Our findings give a new perspective for understanding Andreev reflection.