光晶格动量依赖偶极势中原子运动

研究了原子在光晶格偶极势依赖原子动量情况下的运动, 特别考虑了偶极势对原子动量的依赖特性. 对动量和位置的方差研究表明, 原子的动量方差呈现压缩性质, 位置方差呈现放大性质.据此我们预言光晶格动量依赖偶极势中的单粒子态可能接近动量压缩线态. 研究结果还表明, 红失谐情况下原子的动量演化可分为三个过程: 第一个过程是慢减速过程, 初始动量较大的原子, 动量以近似阻尼振荡的形式衰减; 第二个过程是快减速过程, 当动量被减速到接近到光子动量时, 动量迅速减小到hk(Ω/γ)², 其中hk为光子动量, Ω为拉比频率, γ为原子波函数衰减函数; 第三个过程是原子被囚禁过程, 当原子动能被降低到小于势井深度时, 原子被囚禁在晶格波腹附近. 关键词： 动量演化 光晶格 压缩态

Atom movement in momentum dependent light dipole lattices

Atom movement in light-induced dipole lattices is investigated in this paper. Momentum-dependence of the dipole potential is particularly considered. Momentum squeezed variance and position amplified variance feature are revealed, from which we predict that a single particle state of boson atoms confined in optical lattice will approach to a momentum squeezed line state. The results show also that under red detune, the atom movement experiences three phases. In the first phase, the atom is slowed down gradually in a long period with atom momentum damply oscillating. In the second phase, atom momentum will quickly reduce to hk(Ω/γ)² with hk momentum of one photon, Ω Rabi frequency, and γ decay constant of atom wave function, as the momentum reduces to the momentum of one photon. Finally, atoms will be confined in the vicinity of wave nodes.
Keywords： momentum evolution optical lattice squeezed state