Time-reversal symmetry breaking in superconductors through loop supercurrent order
Time-reversal symmetry breaking in superconductors through loop supercurrent order
复制标题
DOI：
10.1088/1367-2630/ac17ba
复制
发表时间：
2021-08-01
影响因子：
3.3
通讯作者：
Quintanilla, Jorge
中科院分区：
文献类型：
--
作者：
Ghosh, Sudeep Kumar;Annett, James F.;Quintanilla, Jorge
我们提出了一种新的超导基态，其中微观超导电流回路自发地形成在超导转变温度下的单位晶胞内，只有均匀的，现场和轨道内的单重配对。由于循环电流的存在，超导态的时间反演对称性（TRS）自发破缺。使用金斯堡-朗道理论，我们详细描述了这些电流是如何出现在一个玩具模型。我们讨论了晶体对称性的要求更普遍地实现这样的状态，并表明，它们是满足Re-6 X（X = Zr，Hf，Ti）家庭的TRS打破，但在其他方面似乎是传统的，超导体。我们估计所产生的内部磁场的上限，并发现它与最近的μ子自旋弛豫实验是一致的。
We propose a novel superconducting ground state where microscopic supercurrent loops form spontaneously within a unit cell at the superconducting transition temperature with only uniform, onsite and intra-orbital singlet pairing. As a result of the circulating currents time-reversal symmetry (TRS) is spontaneously broken in the superconducting state. Using Ginzburg-Landau theory we describe in detail how these currents emerge in a toy model. We discuss the crystallographic symmetry requirements more generally to realize such a state and show that they are met by the Re-6 X (X = Zr, Hf, Ti) family of TRS-breaking, but otherwise seemingly conventional, superconductors. We estimate an upper bound for the resulting internal magnetic fields and find it to be consistent with recent muon-spin relaxation experiments.