Absence of spontaneous time-reversal symmetry breaking and ferromagnetism in superconducting NiBi3 single crystal
Absence of spontaneous time-reversal symmetry breaking and ferromagnetism in superconducting NiBi3 single crystal
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DOI：
10.1103/physrevb.107.024415
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发表时间：
2022-08
影响因子：
3.7
通讯作者：
Jingyuan Wang;Camron Farhang;Di Yue;Xiaofeng Jin;Xiangde Zhu;J. Xia
中科院分区：
文献类型：
--
作者：
Jingyuan Wang;Camron Farhang;Di Yue;Xiaofeng Jin;Xiangde Zhu;J. Xia
最近的实验指出，外延Bi/Ni双层中存在自发时间反转对称破断（TRSB）的手性p波类超导性，使其成为探索拓扑保护量子计算有用的物理的有前途的平台。有趣的是，有证据表明，在非外延的Bi/Ni双分子层中，超导性是由于NiBi 3的形成而产生的，据报道，NiBi 3在表面上具有共存的铁磁性和超导序。我们使用Sagnac干涉仪对单晶NiBi 3进行了高分辨率的表面磁光克尔效应（SMOKE）测量，发现除了困涡流的贡献外，没有任何自发克尔信号的迹象。这强烈表明NiBi 3中不存在TRSB，无论是由于TRSB处于超导状态还是由于任何共存的铁磁性，我们得出结论，非外延Bi/Ni中的超导性与外延Bi/Ni中的超导性明显不同。
Recent experiments have pointed to a chiral p-wave-like superconductivity in epitaxial Bi/Ni bilayers that are spontaneously time-reversal symmetry breaking (TRSB), making it a promising platform for exploring physics useful for topologically protected quantum computing. Quite intriguingly, evidence has emerged that in non-epitaxial Bi/Ni bilayers, superconductivity arises due to the formation of NiBi 3 , which has been reported to host coexisting ferromagnetic and superconducting orders at the surface. We perform high resolution surface magneto-optic Kerr effect (SMOKE) measurements using a Sagnac interferometer on single crystal NiBi 3 and find no sign of any spontaneous Kerr signal except for contributions from trapped vortices. This strongly indicates the absence of TRSB in NiBi 3 , whether due to TRSB in the superconducting state or any coexisting ferromagnetism, and we conclude that the superconductivity found in non-epitaxial Bi/Ni is distinctively different from that in epitaxial Bi/Ni.