Majorana fermions in one-dimensional spin-orbit coupled Fermi gases

TL;DR

This paper investigates how one-dimensional spin-orbit coupled Fermi gases can host Majorana fermions at their boundaries, revealing a transition from trivial to topological superfluid phases as laser intensity increases.

Contribution

It provides a theoretical framework for understanding Majorana fermions in 1D Fermi gases with spin-orbit coupling, including self-consistent calculations and analytical wavefunction expressions.

Findings

Identification of topological phase transition driven by Raman laser intensity.

Analytic expression for Majorana fermion wavefunction at the trap boundary.

Calculation of density of states at finite temperature.

Abstract

We theoretically study trapped one-dimensional Fermi gases in the presence of spin-orbit coupling induced by Raman lasers. The gas changes from a conventional (non-topological) superfluid to a topological superfluid as one increases the intensity of the Raman lasers above a critical chemical-potential dependent value. Solving the Bogoliubov-de Gennes equations self-consistently, we calculate the density of states in real and momentum space at finite temperatures. We study Majorana fermions (MFs) which appear at the boundaries between topologically trivial and topologically non-trivial regions. We linearize the trap near the location of a MF, finding an analytic expression for the localized MF wavefunction and the gap between the MF state and other edge states.