Majorana Bound States in Proximity Junctions of Superconducting Nanowires with Dresselhaus Spin-orbit Coupling

TL;DR

This paper theoretically investigates Majorana bound states in superconducting nanowires with Dresselhaus spin-orbit coupling, revealing their topological protection and quantized conductance signatures in junctions.

Contribution

It demonstrates the existence and robustness of Majorana bound states in Dresselhaus nanowires and links their number to propagating channels, with implications for quantum transport.

Findings

Majorana bound states are protected by chiral symmetry even with impurities.

Zero-bias conductance is quantized at 2e^2 Nc/h, independent of disorder.

Number of Majorana states equals the number of propagating channels Nc.

Abstract

We theoretically study transport properties of nanowires with the Dresselhaus [110] spin-orbit coupling under the in-plane Zeeman potential and the proximity-induced s-wave pair potential. In the topologically nontrivial phase, the nanowire hosts the Majorana fermions at its edges and the number of the Majorana bound states is equal to the number propagating channels (Nc). When we attach a normal metal to the superconductor, such Majorana bound states penetrate into the dirty normal segment and form the Nc resonant transmission channels there. We show that chiral symmetry of the electronic states protects the Majorana bound states at the zero energy even in the presence of impurities. As a result, we find that the zero-bias conductance of normal-nanowire/superconducting-nanowire junctions is quantized at 2e2Nc/h independent of the random potentials.