Three-component topological superfluid in one-dimensional Fermi gases with spin-orbit coupling

TL;DR

This paper theoretically explores one-dimensional three-component spin-orbit-coupled Fermi gases, revealing phase transitions to topological superfluids with potential for experimental realization and hosting Majorana zero modes.

Contribution

It introduces a detailed phase diagram for three-component Fermi gases, showing their advantage over two-component systems for realizing topological superfluids.

Findings

System transitions from BCS to topological superfluid with increasing Zeeman field.

Presence of two Majorana zero energy regions at higher magnetic fields.

Three-component systems require smaller magnetic fields, aiding experimental realization.

Abstract

We theoretically investigate one-dimensional three-component spin-orbit-coupled Fermi gases in the presence of Zeeman field. By solving the Bogoliubov-de-Gennes equations, we obtain the phase diagram at given chemical potential and order parameter. We show that the system undergoes a phase transition from Bardeen-Cooper-Schrieffer superfluid to topological superfluid as increasing the intensity of Zeeman field. By comparing to the two-component system, we find, besides the topological phase transition from the trivial superfluid to nontrivial topological superfluid, the system can always be in a nontrivial topological superfluid, and there are two Majorana zero energy regions while increasing the magnetic field. We find the three-component spin-orbit-coupled Fermi gases in certain parameter range is more optimizing for experimental realization due to the smaller magnetic field needed. We therefore propose a promising candidate for realizing topological superfluid.