2021/09/05 by Eduardo Serrano-Ensástiga, E. Serrano-Ensástiga, Francisco Mireles +1
Physics and Astronomy · #Antiferromagnetism #Bose–Einstein condensate #Cold Atom Physics and Bose-Einstein Condensates #Condensed matter physics #Ferromagnetism #Metastability #Phase (matter) #Phase boundary #Phase diagram #Phase transition #Physics #Physics of Superconductivity and Magnetism #Quantum many-body systems #Quantum mechanics #Spin (aerodynamics) #Spinor #Thermodynamics #cond-mat.quant-gas #quant-ph
paper · pdf · doi:10.1103/physreva.104.063308
published as Phys. Rev. A 104, 063308 (2021) · 14 pages, 6 figures
arxiv created 2021/09/05 · openalex created_date 2021/09/13 · openalex publication_date 2021/12/13 · arxiv updated 2022/01/12 · openalex updated_date 2026/08/05
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 paper, 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 self-consistency methods. 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 in temperature induces a traceable shift of the ferromagnetic-polar transition boundary, behavior previously not noted by self-consistent mean-field calculations.