Spin Josephson effects of spin-orbit-coupled Bose-Einstein condensates in a non-Hermitian double well
| Autor: | Tang, Jia, Hu, Zhou, Zeng, Zhao-Yun, Xiao, Jinpeng, Li, Lei, Chen, Yajiang, Chen, Ai-Xi, Luo, Xiaobing |
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| Rok vydání: | 2022 |
| Předmět: | |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1088/1361-6455/aca852 |
| Popis: | In this paper, we investigate the spin and tunneling dynamics of a spin-orbit-coupled noninteracting Bose-Einstein condensate in a periodically driven non-Hermitian double-well potential. Under high-frequency driving, we obtain the effective time-averaged Hamiltonian by using the standard time-averaging method, and analytically calculate the Floquet quasienergies, revealing that the parity-time (PT)-breaking phase transition appears even for arbitrarily small non-Hermitian parameters when the spin-orbit coupling strength takes half-integer value, irrespective of the values of other parameters used. When the system is PT-symmetric with balanced gain and loss, we find numerically and analytically that in the broken PT-symmetric regions, there will exist the net spin current together with a vanishing atomic current, if we drop the contribution of the exponential growth of the norm to the current behaviors. When the system is non-PT-symmetric, though the quasienergies are partial complex, a stable net spin current can be generated by controlling the periodic driving field, which is accompanied by a spatial localization of the condensate in the well with gain. The results deepen the understanding of non-Hermitian physics and could be useful for engineering a variety of devices for spintronics. Comment: 12 pages, 6 figures |
| Databáze: | arXiv |
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