We systematically investigated electronic evolutions of non-symmorphic borophene with chemical environments that were realized by the ion exchange method. Electronic structures can be characterized by the topological Z2 invariant. Spectroscopic experiments and DFT calculations unveiled that a sheet of hydrogenated borophene (borophane) is the Dirac nodal loop semimetal (Z2=−1), while a layered crystal of YCrB4 is an insulator (Z2=1). The results demonstrate the electronic topological transition by replacement of the counter atoms on the non-symmorphic borophene layer.
@article{arxiv.2205.05259,
title = {Electronic topological transition of 2D boron by the ion exchange reaction},
author = {Xiaoni Zhang and Yuki Tsujikawa and Ikuma Tateishi and Masahito Niibe and Tetsuya Wada and Masafumi Horio and Miwa Hikichi and Yasunobu Ando and Kunio Yubuta and Takahiro Kondo and Iwao Matsuda},
journal= {arXiv preprint arXiv:2205.05259},
year = {2022}
}