Surface instability in nodal noncentrosymmetric superconductors
Surface instability in nodal noncentrosymmetric superconductors
复制标题
节点非中心对称超导体的表面不稳定性
DOI：
10.1103/physrevb.91.180503
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发表时间：
2015
影响因子：
3.7
通讯作者：
P. M. R. Brydon
中科院分区：
文献类型：
--
作者：
C. Timm;S. Rex;P. M. R. Brydon
我们研究了节点非中心对称超导体表面拓扑保护的零能平带的稳定性，考虑了表面附近间隙的变化。在自洽平均场理论中，我们证明了在低于体转变温度的较宽温度范围内，平坦带仍然存在。然而，在较低温度下存在第二次转变，低于此温度，系统会自发地打破时间反转对称性。表面能带从零能量偏移，变得弱色散。同时，自旋极化和平衡电荷电流在表面区域产生。
We study the stability of topologically protected zero-energy flat bands at the surface of nodal noncentrosymmetric superconductors, accounting for the alteration of the gap near the surface. Within a self-consistent mean-field theory, we show that the flat bands survive in a broad temperature range below the bulk transition temperature. There is a second transition at a lower temperature, however, below which the system spontaneously breaks time-reversal symmetry. The surface bands are shifted away from zero energy and become weakly dispersive. Simultaneously, a spin polarization and an equilibrium charge current develop in the surface region.