Majorana fermions in s-wave noncentrosymmetric superconductor with Rashba and Dresselhaus (110) spin-orbit couplings

TL;DR

This paper explores how asymmetric spin-orbit interactions in noncentrosymmetric superconductors can host Majorana fermions, revealing a novel semimetal phase with flat Andreev bound states that are experimentally detectable.

Contribution

It identifies a new semimetal phase in s-wave noncentrosymmetric superconductors with Rashba and Dresselhaus (110) couplings supporting Majorana fermions.

Findings

Existence of a semimetal phase with flat Andreev bound states.

Presence of Majorana fermions in the phase diagram.

Experimental signatures in tunneling conductance measurements.

Abstract

The asymmetric spin-orbit (SO) interactions play a crucial role in realizing topological phases in noncentrosymmetric superconductor (NCS).We investigate the edge states and the vortex core states in s-wave NCS with Rashba and Dresselhaus (110) SO couplings by both numerical and analytical methods. In particular, we demonstrate that there exists a novel semimetal phase characterized by the flat Andreev bound states in the phase diagram of the s-wave Dresselhaus NCS which supports the emergence of Majorana fermion (MF). The flat dispersion implies a peak in the density of states which has a clear experimental signature in the tunneling conductance measurements and the MFs proposed here should be experimentally detectable.