Odd-even effect of transport through a chain of Majorana bound states in a T-shaped junction

¹ College of Sciences, Northeastern University - Shenyang 110004, China
² Department of Applied Physics, Donghua University - Shanghai 201620, China
³ Institute of Physics, Chinese Academy of Sciences - Beijing 100080, China
⁴ Key Laboratory of Physics and Technologies for Advanced Batteries, Ministry of Education, Department of Physics, Jilin University Changchun 130023, China

Received: 4 November 2013
Accepted: 22 April 2014

Abstract

We investigate the transport characteristics of a chain of Majorana bound states (MBSs) in a T-shaped junction, where two normal leads are coupled to the same terminate MBS. We find the apparent odd-even effect in the transport process. Namely, when the MBS number is odd, the conductance spectrum exhibits a peak in the zero-bias limit. Besides, the shot noise Fano factor in the zero-bias limit and the conductance maximum are related by equation with . Otherwise, in the case of even-numbered MBSs, at the zero-bias limit, the conductance encounters its zero value, and the relation between F₀ and changes as . Further investigation shows that these two kinds of relations are caused by the different interplay mechanisms between the crossed Andreev reflection and the local Andreev reflection. In addition, it is observed that the fluctuation of the inter-MBS couplings contributes little to the transport results. We ascertain that these results are helpful for understanding the MBS signature in transport spectra.