Raman-dressed spin-1 spin-orbit-coupled quantum gas
Raman-dressed spin-1 spin-orbit-coupled quantum gas
复制标题
DOI：
10.1103/physreva.89.023630
复制
发表时间：
2014-02-24
影响因子：
2.9
通讯作者：
Oehberg, Patrik
中科院分区：
文献类型：
--
作者：
Lan, Zhihao;Oehberg, Patrik
最近实现的自旋轨道耦合量子气体[Lin et al.，Nature（伦敦）471，83（2011）; Wang等人，物理修订信函109，095301（2012）; Cheuk等人，同上，109，095302（2012）]标志着冷原子界的突破。在这些实验中，我们采用拉曼修整的方法，从超精细流形中选取两个超精细态，模拟赝自旋1/2自旋轨道耦合系统，该方法适用于玻色子和费米子气体。在本文中，我们表明，在这些实验中使用的方法可以推广到创建任何大的赝自旋自旋轨道耦合气体，如果更多的超精细态的拉曼激光器的平等耦合。作为一个例子，我们详细地研究了一个由三个超精细态组成的量子气体在拉曼激光耦合下的性质，发现当三个超精细态的能级位移相当时，在能带色散的底部会出现三重简并极小值，从而实现了一个自旋为1的自旋-轨道耦合量子气体.这三个最小区域的一个新特征是，可以有两种不同类型的条纹相具有不同的波长，这与自旋1旋量玻色-爱因斯坦凝聚体的铁磁相和极性相没有自旋轨道耦合有一个有趣的联系。
The recently realized spin-orbit-coupled quantum gases [Lin et al., Nature (London) 471, 83 (2011); Wang et al., Phys. Rev. Lett. 109, 095301 (2012); Cheuk et al., ibid. 109, 095302 (2012)] mark a breakthrough in the cold atom community. In these experiments, two hyperfine states are selected from a hyperfine manifold to mimic a pseudospin-1/2 spin-orbit-coupled system by the method of Raman dressing, which is applicable to both bosonic and fermionic gases. In this paper, we show that the method used in these experiments can be generalized to create any large pseudospin spin-orbit-coupled gas if more hyperfine states are coupled equally by the Raman lasers. As an example, we study, in detail, a quantum gas with three hyperfine states coupled by the Raman lasers and show, when the state-dependent energy shifts of the three states are comparable, triple-degenerate minima will appear at the bottom of the band dispersions, thus, realizing a spin-1 spin-orbit-coupled quantum gas. A novel feature of this three-minima regime is that there can be two different kinds of stripe phases with different wavelengths, which has an interesting connection to the ferromagnetic and polar phases of spin-1 spinor Bose-Einstein condensates without spin-orbit coupling.