Electronic structures of twist-stacked 1T-TaS2 bilayers

Publication date: Available online 26 April 2019Source: Physics Letters AAuthor(s): Yunting Li, Huaping Xiao, Pan Zhou, Juexian CaoAbstractBy using first-principles calculations, we investigate the effect of the twisted angle (θ) on the electronic structures of two types of 1T-TaS2 bilayers. Our calculation show that with the increase of twisted angles, the formation energy increases for the two types of structures and the band gap for Type II increases while the Type I structures experience a metal-semiconductor transition. The changes are mainly resulted from the interlayer interaction and the redistribution of charge density induced by in-plane distortion. It is found that the structure with θ=32.2° for the Type I is a possible metastable charge-density-wave (CDW) phase. The findings account for the experiment on the CDW gap variation with the twisted angle.

Source: Physics Letters A - April 28, 2019 Category: Physics Source Type: research