Detection of a Majorana-fermion zero mode by a T-shaped quantum-dot structure

TL;DR

This paper theoretically investigates how a Majorana zero mode affects electron transport in a T-shaped quantum-dot structure, revealing conductance signatures that can help detect Majorana bound states.

Contribution

It introduces a novel approach to detect Majorana zero modes using conductance spectra in T-shaped quantum-dot systems, including multi-QD configurations.

Findings

Majorana zero mode dissolves antiresonance in conductance spectrum

A conductance peak of e^2/2h appears at the same energy as the Majorana mode

Conductance results are independent of QD parity in the zero-bias limit

Abstract

Electron transport through the T-shaped quantum-dot (QD) structure is theoretically investigated, by considering a Majorana zero mode coupled to the terminal QD. It is found that in the double-QD case, the presence of the Majorana zero mode can efficiently dissolve the antiresonance point in the conductance spectrum and induce a conductance peak to appear at the same energy position whose value is equal to $e^2/2h$. This antiresonance-resonance change will be suitable to detect the Majorana bound states. Next in the multi-QD case, we observe that in the zero-bias limit, the conductances are always the same as the double-QD result, independent of the parity of the QD number. We believe that all these results can be helpful for understanding the properties of Majorana bound states.