Tuning the Tricritical Point with Spin-orbit Coupling in Polarized Fermionic Condensates

TL;DR

This paper explores how Rashba spin-orbit coupling influences the phase diagram of polarized fermionic gases, revealing expanded superfluid regions and the movement of tricritical points with increasing SOC strength.

Contribution

It demonstrates the impact of spin-orbit coupling on phase transitions and tricritical points in polarized Fermi gases, a novel insight into quantum phase behavior.

Findings

Superfluid regime expands with stronger SOC.

Phase separation region diminishes and disappears at high SOC.

Tricritical point shifts to low temperature, high magnetic field, and high polarization.

Abstract

We investigate a two-component atomic Fermi gas with population imbalance in the presence of Rashba-type spin-orbit coupling (SOC). As a competition between SOC and population imbalance, the finite-temperature phase diagram reveals a large varieties of new features, including the expanding of the superfluid state regime and the shrinking of both the phase separation and the normal regimes. For sufficiently strong SOC, the phase separation region disappears, giving way to the superfluid state. We find that the tricritical point moves toward regime of low temperature, high magnetic field, and high polarization as the SOC increases.