The spontaneous formation of electronic orders is a crucial element for understanding complex quantum states and engineering heterostructures in two-dimensional materials. We report a novel 19×19 charge order in few-layer thick 1T-TaTe2 transition metal dichalcogenide films grown by molecular beam epitaxy, which has not been realized. Our photoemission and scanning probe measurements demonstrate that monolayer 1T-TaTe2 exhibits a variety of metastable charge density wave orders, including the 19×19 superstructure, which can be selectively stabilized by controlling the post-growth annealing temperature. Moreover, we find that only the 19×19 order persists in 1T-TaTe2 films thicker than a monolayer, up to 8 layers. Our findings identify the previously unrealized novel electronic order in a much-studied transition metal dichalcogenide and provide a viable route to control it within the epitaxial growth process.
@article{arxiv.2210.02010,
title = {A novel $\sqrt{19}\times\sqrt{19}$ superstructure in epitaxially grown 1T-TaTe$_2$},
author = {Jinwoong Hwang and Yeongrok Jin and Canxun Zhang and Tiancong Zhu and Kyoo Kim and Yong Zhong and Ji-Eun Lee and Zongqi Shen and Yi Chen and Wei Ruan and Hyejin Ryu and Choongyu Hwang and Jaekwang Lee and Michael F. Crommie and Sung-Kwan Mo and Zhi-Xun Shen},
journal= {arXiv preprint arXiv:2210.02010},
year = {2022}
}