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Ferromagnetic phase transition and Bose-Einstein condensation in spinor Bose gases

Qiang Gu·Richard A. Klemm
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Abstract

Phase transitions in spinor Bose gases with ferromagnetic (FM) couplings are studied via mean-field theory. We show that an infinitesimal value of the coupling can induce a FM phase transition at a finite temperature always above the critical temperature of Bose-Einstein condensation. This contrasts sharply with the case of Fermi gases, in which the Stoner coupling $I_s$ can not lead to a FM phase transition unless it is larger than a threshold value $I_0$. The FM coupling also increases the critical temperatures of both the ferromagnetic transition and the Bose-Einstein condensation.

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Qiang Gu, Richard A. Klemm. 2003-07-02. Ferromagnetic phase transition and Bose-Einstein condensation in spinor Bose gases. https://doi.org/10.1103/physreva.68.031604

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