论文标题
超低费米气体中的角拓扑超流体和拓扑涡流
Angular topological superfluid and topological vortex in an ultracold Fermi gas
论文作者
论文摘要
我们表明，在旋转轨道 - 角摩膜偶联（SOAMC）下，在超低的费米气体中配对可以获取在量化的角度自由度中编码的拓扑特征。由此产生的拓扑超流体是其在一维费米气体中具有自旋轨道耦合的角度类似物的角度类似物，但其特征是在Angular Momentum空间中定义的Zak相。调整SOAMC参数后，发生拓扑相变，伴随着准粒子激发差距的闭合。值得注意的是，拓扑涡流状态也可以通过变形费米表面来稳定，而费米表面在坐标和角度摩膜空间中拓扑并非平凡，为在量子信息和量子控制中应用提供了有趣的潜力。我们讨论如何在实验中检测到拓扑相变和外来涡流状态。
We show that pairing in an ultracold Fermi gas under spin-orbital-angular-momentum coupling (SOAMC) can acquire topological characters encoded in the quantized angular degrees of freedom. The resulting topological superfluid is the angular analog of its counterpart in a one-dimensional Fermi gas with spin-orbit coupling, but characterized by a Zak phase defined in the angular-momentum space. Upon tuning the SOAMC parameters, a topological phase transition occurs, which is accompanied by the closing of the quasiparticle excitation gap. Remarkably, a topological vortex state can also be stabilized by deforming the Fermi surface, which is topologically non-trivial in both the coordinate and angular-momentum space, offering interesting potentials for applications in quantum information and quantum control. We discuss how the topological phase transition and the exotic vortex state can be detected experimentally.
