Abstract
Honeycomb structures of group IV elements can host massless Dirac fermions with nontrivial 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 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 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.
- Received 24 September 2016
DOI:https://doi.org/10.1103/PhysRevLett.118.096401
© 2017 American Physical Society
Physics Subject Headings (PhySH)
Synopsis
Dirac Cones in Boron’s Version of Graphene
Published 2 March 2017
A one-atom-thick sheet of boron atoms exhibits Dirac cones, marking the first time this electronic property has been found in a material lacking a graphene-like crystal structure.
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