Journal of Physics B Atomic Molecular and Optical Physics
Magnetic phase transitions of nonuniform spin-tensor-momentum coupled Bose–Einstein condensates
Jie Wang, Ning Yue, Ai‐Xia Zhang, Xin Qiao, Ji-Ming Gao, Zi-Fa Yu, Xiaobo Zhang, Ju-Kui Xue
Abstract
Abstract Spin-tensor-momentum coupling (STMC) induces dramatic change of the single-particle energy spectrum, resulting in rich and novel quantum ground state phases. Here, considering the atomic interactions, the STMC induced Z 2 symmetry breaking of the energy band, the tricritical point and the magnetic phase transitions in trapped STMC Bose–Einstein condensates are presented analytically and numerically. We demonstrate that the ground state momentum and spin tensor are coupled by STMC and the asymmetry of the energy band is persistent in STMC system, resulting in phase transition between magnetized and unmagnetized plane wave phases or between the two unmagnetized plane wave phases. The critical conditions for the phase transitions are obtained analytically, clarifying the physical mechanisms behind the phase transitions. Particularly, a tricritical point is predicted, where different types of energy band merge and the first-order phase transition and the second-order phase transition meet. Interestingly, it is shown that the ground state strongly depends on the external trapping potential, establishing a potential method for manipulating the phase transitions of the system. We provide a theoretical evidence for deep understanding and experimental manipulation of novel quantum phases in STMC systems.