Superconductivity in FeSe Thin Films Driven by the Interplay between Nematic Fluctuations and Spin-Orbit Coupling
Superconductivity in FeSe Thin Films Driven by the Interplay between Nematic Fluctuations and Spin-Orbit Coupling
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DOI：
10.1103/physrevlett.117.217003
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发表时间：
2016-11-18
影响因子：
8.6
通讯作者：
Fernandes, Rafael M.
中科院分区：
文献类型：
--
作者：
Kang, Jian;Fernandes, Rafael M.
在FeSe薄膜中观察到的高温超导态的起源，其相图显示没有磁序的迹象，仍然是一个激烈争论的话题。在这里，我们调查是否出现的波动，由于接近一个超导相，这是观察到的这种材料的相图，可以促进超导性。我们发现，光的涨落单独促进高度简并的配对状态，其中s-波和d-波对称性是同样有利的，和T-C因此被抑制。然而，一个相当大的自旋-轨道耦合或反转对称性破缺的存在下，在膜界面升降机这种有害的简并选择的s波状态，在最近的实验建议一致。由此产生的间隙函数显示出弱的各向异性，这与单层FeSe和插入Li 1-x（OH）（x）FeSe的实验一致。
The origin of the high-temperature superconducting state observed in FeSe thin films, whose phase diagram displays no sign of magnetic order, remains a hotly debated topic. Here we investigate whether fluctuations arising due to the proximity to a nematic phase, which is observed in the phase diagram of this material, can promote superconductivity. We find that nematic fluctuations alone promote a highly degenerate pairing state, in which both s-wave and d-wave symmetries are equally favored, and T-c is consequently suppressed. However, the presence of a sizable spin-orbit coupling or inversion symmetry breaking at the film interface lifts this harmful degeneracy and selects the s-wave state, in agreement with recent experimental proposals. The resulting gap function displays a weak anisotropy, which agrees with experiments in monolayer FeSe and intercalated Li1-x(OH)(x)FeSe.