Gapless topological Fulde-Ferrell superfluidity in spin-orbit coupled Fermi gases.
Gapless topological Fulde-Ferrell superfluidity in spin-orbit coupled Fermi gases.
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DOI：
10.1103/physrevlett.113.115302
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发表时间：
2014-02
影响因子：
8.6
通讯作者：
Ye Cao;S. Zou;Xiaji Liu;S. Yi;G. Long;Hui Hu
中科院分区：
文献类型：
--
作者：
Ye Cao;S. Zou;Xiaji Liu;S. Yi;G. Long;Hui Hu
拓扑超流体通常指的是一种超流体状态，这种状态在主体上是有间隙的，但在边界上是金属的。本文报道了在二维自旋-轨道耦合的费米气体中，同时存在面内和面外塞曼场的情况下，具有非均匀Fulde-Ferrell配对序参量的无间隙、拓扑非平凡的超流。Fulde-Ferrell配对--由自旋-轨道耦合和面内塞曼场诱导--是这种无间隙特征的原因。这种奇异的超流体具有显著的Berezinskii-Kosterlitz-Thouless转变温度，并由于其拓扑性质而具有强大的Majorana边缘模以对抗无序。
Topological superfluids usually refer to a superfluid state which is gapped in the bulk but metallic at the boundary. Here we report that a gapless, topologically nontrivial superfluid with an inhomogeneous Fulde-Ferrell pairing order parameter can emerge in a two-dimensional spin-orbit coupled Fermi gas, in the presence of both in-plane and out-of-plane Zeeman fields. The Fulde-Ferrell pairing-induced by the spin-orbit coupling and in-plane Zeeman field-is responsible for this gapless feature. This exotic superfluid has a significant Berezinskii-Kosterlitz-Thouless transition temperature and has robust Majorana edge modes against disorder owing to its topological nature.