Metastable spin-phase diagrams in antiferromagnetic Bose-Einstein condensates

Abstract

Spinor Bose-Einstein condensates under external magnetic fields exhibit well-characterized spin domains of its ground state due to spin-dependent interactions. At low temperatures, collision-induced spin-mixing instabilities may promote the condensate to dwell into metastable states occurring near the phase boundaries. In this work, we study theoretically the metastable spin-phase diagram of a spin-1 antiferromagnetic Bose-Einstein condensate at zero and finite temperatures. The approach makes use of Hartree-Fock theory and exploits the symmetry of the Hamiltonian and of the order parameters yielding a closed system of transcendental equations for the free energy, fully avoiding the use of selfconsistency. Our results are consistent with recent experiments and allow us to explain qualitatively the different types of observed quench dynamics. In addition, we found that similar phenomena should occur in antiferromagnetic spinor condensates with a sudden change in the temperature. It is shown also that the increase of temperature induces a traceable shift of the Ferromagnetic-Polar transition boundary, behavior previously not noticed by selfconsistent mean-field calculations.

14 pages, 6 figures

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Cited by in corpus (4)

• Collective excitations in cigar-shaped spin-orbit coupled spin-1 Bose-Einstein condensates
• Phase characterization of spinor Bose-Einstein condensates: a Majorana stellar representation approach
• Phase diagram of two-component mean-field Bose mixtures
• Thermal effects on the spin domain phases of high spin-f Bose-Einstein condensates with rotational symmetries