Thermodynamics of spin-orbit-coupled Bose-Einstein condensates

TL;DR

This paper develops a quantum field theoretical framework to analyze the thermodynamic behavior of spin-orbit-coupled Bose-Einstein condensates, revealing phase transitions, critical temperatures, and thermodynamic properties influenced by spin-orbit coupling and interactions.

Contribution

It provides exact analytical expressions for critical temperature, specific heat, and entropy in different phases of spin-orbit-coupled BECs, highlighting the effects of spin-orbit coupling and interactions.

Findings

Phase transition driven by temperature in spin-orbit-coupled BECs.

Exact critical temperature independent of trapping potential.

Large specific heat jump at the phase transition.

Abstract

In this paper we develop a quantum field approach to reveal the thermodynamic properties of the trapped BEC with the equal Rashba and Dresselhaus spin-orbit couplings. In the experimentally-feasible regime, the phase transition from the separate phase to the single minimum phase can be well driven by the tunable temperature. Moreover, the critical temperature, which is independent of the trapped potential, can be derived exactly. At the critical point, the specific heat has a large jump and can be thus regarded as a promising candidate to detect this temperature-driven phase transition. In addition, we obtain the analytical expressions for the specific heat and the entropy in the different phases. In the single minimum phase, the specific heat as well as the entropy are governed only by the Rabi frequency. However, in the separate phase with lower temperature, we find that they are determined only by the strength of spin-orbit coupling. Finally, the effect of the effective atom interaction is also addressed. In the separate phase, this effective atom interaction affects dramatically on the critical temperature and the corresponding thermodynamic properties.