Institute for Advanced Study, Tsinghua University, Beijing 100084, China.
State Key Laboratory of Low Dimensional Quantum Physics, Tsinghua University, Beijing 100084, China.
Phys Rev Lett. 2018 Oct 12;121(15):157002. doi: 10.1103/PhysRevLett.121.157002.
The superconducting pairing in Sr_{2}RuO_{4} is widely considered to be chiral p wave with d[over →]{k}∼(k{x}+ik_{y})z[over ^], which belongs to the E_{u} representation of the crystalline D_{4h} group. However, this superconducting order appears hard to reconcile with a number of key experiments. In this Letter, based on symmetry analysis we discuss the possibility of odd-parity pairing with inherent three-dimensional character enforced by the interorbital interlayer coupling and the sizable spin-orbit coupling in the material. We focus on a yet unexplored E_{u} pairing, which contains finite (k_{z}x[over ^], k_{z}y[over ^]) component in the gap function. Under appropriate circumstances a novel time-reversal invariant nematic pairing can be realized. This nematic superconducting state could make contact with some puzzling observations on Sr_{2}RuO_{4}, such as the absence of spontaneous edge current and no evidence of split transitions under uniaxial strains.
Sr_{2}RuO_{4}中的超导配对被广泛认为是手性 p 波，具有 d[over →]{k}∼(k{x}+ik_{y})z[over ^]，属于晶体 D_{4h}群的 E_{u}表示。然而，这种超导有序似乎与许多关键实验难以协调。在这封信中，我们基于对称性分析，讨论了由轨道间层间耦合和材料中可观的自旋轨道耦合强制的具有固有三维特性的奇数对配对的可能性。我们专注于一个尚未探索的 E_{u}配对，其中在能隙函数中包含有限的 (k_{z}x[over ^], k_{z}y[over ^])分量。在适当的情况下，可以实现一种新的时间反演不变的向列超导态。这种向列超导态可以与 Sr_{2}RuO_{4}上的一些令人困惑的观察结果联系起来，例如没有自发边缘电流，以及在单轴应变下没有分裂跃迁的证据。
