Superconductivity in twisted transition metal dichalcogenide homobilayers
Jihang Zhu, Yang-Zhi Chou, Ming Xie, S. Das Sarma
Abstract
Recently, robust superconductivity has been independently reported in twisted ${\mathrm{WSe}}_{2}$ bilayers by two separate groups [Y. Xia et al., arXiv:2405.14784; Y. Guo et al., Nature (London) 637, 839 (2025)]. In light of this, we explore the possibility of a universal superconducting pairing mechanism in twisted ${\mathrm{WSe}}_{2}$ bilayers. Using a continuum band structure and a phenomenological boson-mediated effective electron-electron attraction, we find that intervalley intralayer pairing predominates over interlayer pairing. Notably, despite very different experimental conditions, both twisted ${\mathrm{WSe}}_{2}$ samples exhibit a comparable effective attraction strength for superconductivity. This consistency in the two experiments suggests that the dominant pairing glue is likely independent of the twist angle and layer polarization, pointing to a universal underlying boson-induced pairing mechanism. We speculate on the possible mechanisms in the discussion.