Novel Superconducting Phases in Monolayer Transition Metal Dichacolgenides*

It was recently discovered that transition metal dichacolgenides (TMDs), such as NbSe2 and MoS2, can be superconducting down to monolayer thickness. Importantly, due to the breaking of in-plane mirror symmetry and strong orbital spin-orbit coupling (SOC), electrons in monolayer TMDs experience Ising SOC which pins electron spins to the out-of-plane directions. It has been shown experimentally and theoretically that Ising SOC can strongly enhance the in-plane upper critical field of superconducting TMDs several times beyond the Pauli limit [1-3]. In this talk, we will further explore how Ising SOC can induce novel superconducting phases in monolayer TMDs including a spin-triplet nodal superconducting phase and a spin-singlet topological nodal superconducting phase.

1. J. M. Lu, O. Zeliuk, I. Leermakers, Noah F. Q. Yuan, U. Zeitler, K. T. Law and J. T. Ye, Science 350, 1353 (2015).
2. X. Xi, Z. Wang, W. Zhao, J-H Park, K. T. Law, H. Berger, L. Forró, J. Shan, K. F. Mak, Nature Physics 12, 139-143 (2016).
3. Y Saito et al. Nature Physics 12, 144-149 (2016).