2024/01/23 by Pye Ton How, How, Pye Ton, Sungkit Yip +1 · 1 citation
Physics and Astronomy · #Advanced Thermodynamics and Statistical Mechanics #Cold Atom Physics and Bose-Einstein Condensates #FOS: Physical sciences #Quantum Gases (cond-mat.quant-gas) #Quantum, superfluid, helium dynamics
paper · pdf · doi:10.48550/arxiv.2401.12541
openalex publication_date 2024/01/23 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The strongly ferromagnetic spin-1 Bose-Einstein condensate (BEC) has recently been realized with atomic 7Li. It was predicted that a strong ferromagnetic interaction can drive the normal gas into a magnetized phase at a temperature above the superfluid transition, and 7Li likely satisfies the criterion. We re-examine this theoretical proposal employing the two-particle-irreducible (2PI) effective potential, and conclude that there exists no stable normal magnetized phase for a dilute ferromagnetic Bose gas. For 7Li, we predict that the normal gas undergoes a joint first order transition and jump directly into a state with finite condensate density and magnetization. We estimate the size of the first order jump, and examine how a partial spin polarization in the initial sample affects the first order transition. We propose a qualitative phase diagram at fixed temperature for the trapped gas.