标题： 伊辛超导体的上临界场和配对对称性 显示英文标题

标题： Upper critical field and pairing symmetry of Ising superconductors

摘要： 鉴于在各种过渡金属二硫属化物（TMD）超导体中测得的临界场$H_c$尚未被充分理解，我们研究了其随温度和自旋-轨道耦合（SOC）的标度行为。 通过计算多口袋系统中的自旋磁化率，我们发现SOC具有节点点的费米面（FS）部分可以比其余费米面贡献大几个数量级，因此设定了$H_c$，假设存在常规的单重态超导序参量。 布里渊区中伊辛SOC的节点线由对称性决定，因此当它们与费米面口袋相交时会产生这样的节点点，这在单层 NbSe$_2$和 TaS$_2$中确实如此，但在栅控 MoS$_2$和 WS$_2$中并非如此。 我们的分析重新解释了现有的测量结果，得出结论：在具有SOC节点的口袋上主导的单重态序参量与所有单层伊辛超导体的$H_c(T)$数据一致，与之前矛盾的配对假设相反。 最后，我们表明该理论也与同型双层TMD的数据一致。 显示英文摘要

摘要： Motivated by the fact that the measured critical field $H_c$ in various transition metal dichalcogenide (TMD) superconductors is poorly understood, we reexamine its scaling behavior with temperature and spin-orbit coupling (SOC). By computing the spin-susceptibility in a multipocket system, we find that segments of the Fermi Surface (FS) at which the SOC has nodal points can have a contribution orders of magnitude larger than the remaining FS, hence setting the $H_c$, assuming the presence of a conventional singlet superconducting order parameter. Nodal lines of an Ising SOC in the Brillouin zone are imposed by symmetry, so they cause such nodal points whenever they intersect an FS pocket, which is indeed the case in monolayer NbSe$_2$ and TaS$_2$, but not in gated MoS$_2$ and WS$_2$. Our analysis reinterprets existing measurements, concluding that a dominant singlet-order parameter on pockets with SOC nodes is consistent with the $H_c(T)$ data for all monolayer Ising superconductors, in contrast to previous contradictory pairing assumptions. Finally, we show that the theory is also consistent with data on homobilayer TMDs.