Optical study of electric field tunable 2D semiconductor moiré superlattices

Moiré superlattices based on graphene or transition metal dichalcogenide (TMD) heterostructures provide an interesting platform to explore emerging quantum phases in the strong correlation regime. The large electron mass in monolayer TMDs and the lack of magic angle requirement make TMD moiré heterostructures a particularly robust platform for studying problems in strong electron correlation physics[1]. For instance, it has been recently shown that WSe2/WS2 moiré superlattices can simulate the physics of the triangular lattice Hubbard model [2]. Whereas electrostatic doping can continuously tune the filling factor of the system, a vertical displacement field could also effectively tune the relative band alignment of the heterostructure and other important parameters of this strongly correlated system. In this talk, I will discuss our recent optical study on electric field tunable TMD moiré superlattices and the search for novel quantum phases of matter.

[1]Wu, Fengcheng, et al. "Hubbard model physics in transition metal dichalcogenide moiré bands." Physical review letters121.2(2018): 026402.
[2]Tang, Yanhao, et al. "WSe2/WS2 moiré superlattices: a new Hubbard model simulator." arXiv preprint arXiv:1910.08673(2019).