Honeycomb structures of group IV elements can host massless Dirac fermions with non-trivial Berry phases. Their potential for electronic applications has attracted great interest and spurred a broad search for new Dirac materials especially in monolayer structures. We present a detailed investigation of the \beta 12 boron sheet, which is a borophene structure that can form spontaneously on a Ag(111) surface. Our tight-binding analysis revealed that the lattice of the \beta 12-sheet could be decomposed into two triangular sublattices in a way similar to that for a honeycomb lattice, thereby hosting Dirac cones. Furthermore, each Dirac cone could be split by introducing periodic perturbations representing overlayer-substrate interactions. These unusual electronic structures were confirmed by angle-resolved photoemission spectroscopy and validated by first-principles calculations. Our results suggest monolayer boron as a new platform for realizing novel high-speed low-dissipation devices.
@article{arxiv.1702.00592,
title = {Dirac fermions in borophene},
author = {Baojie Feng and Osamu Sugino and Ro-Ya Liu and Jin Zhang and Ryu Yukawa and Mitsuaki Kawamura and Takushi Iimori and Howon Kim and Yukio Hasegawa and Hui Li and Lan Chen and Kehui Wu and Hiroshi Kumigashira and Fumio Komori and Tai-Chang Chiang and Sheng Meng and Iwao Matsuda},
journal= {arXiv preprint arXiv:1702.00592},
year = {2017}
}
Comments
accepted for publication in Physical Review Letters