Oscillation of the spin-currents of cold atoms on a ring due to light-induced spin–orbit coupling*
Xie Wen-Fanga), He Yan-Zhangb), Bao Cheng-Guangb)†
       
Up-density n ↑ versus θ with ϕ = π /2. The densities are given by 20 curves for a sequence of τ . Starting from τ = 0, in each step τ is increased by 1/40. The 20 curves in the sequence are divided into 4 groups. The n ↑ of each group has been shifted up by two relative to its preceding group, for a clearer perspective. The five n ↑ in each group are plotted in solid, dash, dash–dot, dash–dot–dot, and dot lines, respectively, according to the time-sequence ( τ = 0 is the horizontal solid line in the lowest group). The parameters are q = 1, β = 2, γ = 10, and δ = 1. The vertical dotted lines are also for guiding the eyes.