论文标题
拓扑耦合超导性超导性的拓扑耦合单层$ _2 $
Spin-orbit-parity coupled superconductivity in topological monolayer WTe$_2$
论文作者
论文摘要
最近的实验报告了单层1T $'$ -WTE $ _2 $中的门引起的超导性，这是其正常状态下的二维拓扑绝缘子[1，2]。平面上的临界场$ b_ {c2} $被发现超过了1-3次的常规Pauli Promagnetic lim $ b_p $。这种增强无法通过传统的自旋轨道耦合来解释，该耦合由于反转对称而消失。在这项工作中，我们推出了Centrosymmmore 1t $'$ -WTE $ _2 $的一些独特的超导性能，这些特性是由自旋，动量和乐队偶然自由度的耦合而产生的。由于这种自旋 - 轨道 - 超数耦合：（i）在$ b_ {c2} $上有一阶超导体 - 金属过渡高于Pauli progaragnetic lim $ b_p $，（ii）自旋 - 敏感性，（ii）自旋 - 敏感性是各向异性的，对于偏置和anistrane方向和anisotrapic $ b_} $ andi andii $ b_} $ b_ {c2} $表现出强大的门依赖性，因为旋转轨道 - 准则耦合仅在拓扑带交叉点附近很重要。还讨论了SOPC对拓扑非平凡的轨道间配对阶段的重要性。我们的理论通常适用于具有拓扑带反转的中心对称材料。
Recent experiments reported gate-induced superconductivity in the monolayer 1T$'$-WTe$_2$ which is a two-dimensional topological insulator in its normal state [1, 2]. The in-plane upper critical field $B_{c2}$ is found to exceed the conventional Pauli paramagnetic limit $B_p$ by 1-3 times. The enhancement cannot be explained by conventional spin-orbit coupling which vanishes due to inversion symmetry. In this work, we unveil some distinctive superconducting properties of centrosymmetric 1T$'$-WTe$_2$ which arise from the coupling of spin, momentum and band parity degrees of freedom. As a result of this spin-orbit-parity coupling: (i) there is a first-order superconductor-metal transition at $B_{c2}$ much higher than the Pauli paramagnetic limit $B_p$, (ii) spin-susceptibility is anisotropic with respect to in-plane directions and results in anisotropic $B_{c2}$ and (iii) the $B_{c2}$ exhibits a strong gate dependence as the spin-orbit-parity coupling is significant only near the topological band crossing points. The importance of SOPC on the topologically nontrivial inter-orbital pairing phase is also discussed. Our theory generally applies to centrosymmetric materials with topological band inversions.
