Twist angle control of charge density wave transitions in 1T–TaS2 homostructures

Abstract

Twisted homostructures provide a versatile platform to engineer interlayer coupling and collective orders via moiré superlattices. While the effectiveness of the moiré potential in modulating charge density waves (CDWs) has been established through spectroscopic techniques, systematic investigations through electrical transport measurements remain scarce. Here, by leveraging interfacial moiré superlattices, we characterize the phase transition between the nearly commensurate CDW state and the incommensurate CDW state in twisted 1T-TaS2 homostructures. A two-step transition is observed in twisted 1T-TaS2 homostructures, which is in marked contrast to the single and smooth transition of pristine sample. The two–step transition behavior persists over twist angles from 0° to 58° and for excitation currents spanning two orders of magnitude. These features are consistent with a moiré potential induced periodic pinning landscape for nearly commensurate CDW domain walls at the twisted interface. Our results establish twist angle as an effective control knob for engineering CDWs in layered materials and open routes to moiré superlattice based device concepts.