标题： 自旋-轨道-宇称耦合超导体中的单重态-三重态混合态 显示英文标题

标题： Singlet-triplet mixed state in spin-orbital-parity coupled superconductors

摘要： 与非中心对称超导体不同，中心对称超导体中自旋单态和自旋三重态配对混合的影响仍然模糊。最近，实验上证明了在中心对称过渡金属二硫化物中，自旋、轨道和宇称（$p$-，$d$-轨道）自由度的耦合会诱导出超出泡利极限的各向异性增强的面内临界磁场，这被称为自旋-轨道-宇称耦合（SOPC）超导体。在本工作中，我们表明SOPC会在该系统的拓扑能带反转附近诱导出强烈的自旋单态和自旋三重态配对混合。此外，我们发现这种混合的存在从增强和各向异性两方面提供了对观测到的面内上临界场$B_{c2}$的密切解释。我们还提出测量2M-WS$_2$与铁磁（FM）电极之间的等自旋安德列夫反射来检测2M-WS$_2$中的自旋三重态配对。我们的工作为研究具有强自旋-轨道宇称耦合的中心对称超导体中的自旋单态和自旋三重态配对开辟了一条道路。 显示英文摘要

摘要： Unlike noncentrosymmetric superconductors, the effects of spin singlet- and spin triplet-pairing mixing in centrosymmetric superconductors remain ambiguous. Recently, it was experimentally demonstrated that an anisotropically enhanced in-plane critical fields beyond Pauli limit would be induced by the coupling of spin,orbit and parity ($p$-, $d$-orbitals) degrees of freedom in centrosymmetric transition metal dichacogenides , which is called as spin-orbit-parity coupled (SOPC) superconductors. In this work, we show that the SOPC would induce a strong spin-singlet and spin-triplet pairing mixing near the topological band inversion in this system. Moreover, we find that the presence of such mixing provides a close explanation of the observed the in-plane upper critical fields $B_{c2}$ in terms of both the enhancement and anisotropy. We also propose measuring the equal-spin Andreev reflection between 2M-WS$_2$ and a ferromagnetic (FM) lead to detect the spin-triplet pairing in 2M-WS$_2$. Our work paves a way to study the spin-singlet and spin-triplet pairing in centrosymmetric superconductors with strong spin-orbital parity coupling.