Fermi Gases with Synthetic Spin-Orbit Coupling

TL;DR

This paper reviews recent advances in ultracold Fermi gases with synthetic spin-orbit coupling, highlighting theoretical changes in properties and potential for exotic superfluid phases, and discusses experimental progress in realizing and characterizing these systems.

Contribution

It provides a comprehensive overview of theoretical predictions and recent experimental realizations of spin-orbit coupled Fermi gases, emphasizing the emergence of exotic superfluid phases.

Findings

Spin-orbit coupling dramatically alters Fermi gas properties.

Experimental realization of equal Rashba-Dresselhaus coupling via Raman process.

Potential observation of exotic superfluid phases in strongly-interacting gases.

Abstract

We briefly review recent progress on ultracold atomic Fermi gases with different types of synthetic spin-orbit coupling, including the one-dimensional (1D) equal weight Rashba-Dresselhaus and two-dimensional (2D) Rasbha spin-orbit couplings. Theoretically, we show how the single-body, two-body and many-body properties of Fermi gases are dramatically changed by spin-orbit coupling. In particular, the interplay between spin-orbit coupling and interatomic interaction may lead to several long-sought exotic superfluid phases at low temperatures, such as anisotropic superfluid, topological superfluid and inhomogeneous superfluid. Experimentally, only the first type - equal weight combination of Rasbha and Dresselhaus spin-orbit couplings - has been realized very recently using a two-photon Raman process. We show how to characterize a normal spin-orbit coupled atomic Fermi gas in both non-interacting and strongly-interacting limits, using particularly momentum-resolved radio-frequency spectroscopy. The experimental demonstration of a strongly-interacting spin-orbit coupled Fermi gas opens a promising way to observe various exotic superfluid phases in the near future.