學術報告:Quantum Spin Dynamics in a Normal Bose Gas with Spin-orbit Coupling

來源:  發布時間:2019-06-28 11:27:02 點擊次數:

報告題目:Quantum Spin Dynamics in a Normal Bose Gas with Spin-orbit Coupling

報告人:張世忠 (香港大學物理系)

報告時間:201974日(星期四)上午9:30 11:00



We discuss the spin dynamics of a two-component Bose gas with spin-orbit coupling realised in cold atom experiments. Taking into account of the effect originally discovered by Leggett and Rice, we derive a set of hydrodynamic equations that describes the spin evolution in both adiabatic and diabatic regimes. We show that exact solution corresponding to persistent spin helix exists and discuss the stability of spin helical structure with general wave vector. In the adiabatic regime, the transverse spin decays parabolically in the short-time limit and exponentially in the long-time limit, depending on initial polarisation. In contrast, in the diabatic regime, transverse spin density and current oscillate in a way similar to the charge-current oscillation in an undamped LC circuit. Finally, using realistic experimental parameters for 87Rb, we show that the time scales for spin dynamics is of order of milliseconds to a few seconds and can hopefully be observed experimentally.

邀請人: 王宇 教授

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