Title: Electronic properties of $8\text{-}\mathit{Pmmn}$ borophene

Abstract

First-principles calculations on monolayer 8-Pmmn borophene are reported to reveal unprecedented electronic properties in a two-dimensional material. Based on a Born effective charge analysis, 8-Pmmn borophene is the first single-element-based monolayered material exhibiting two sublattices with substantial ionic features. We observed Dirac cones are actually formed by the p(z) orbitals of one of the inequivalent sublattices composed of uniquely four atoms, yielding an underlying hexagonal network topologically equivalent to distorted graphene. One significant physical outcome of this effect includes the possibility of converting metallic 8-Pmmn borophene into an indirect band gap semiconductor by means of external shear stress. Furthermore, the stability of the strained structures are supported by a phonon frequency analysis. The Dirac cones are sensitive to the formation of vacancies only in the inequivalent sublattice electronically active at the Fermi level.

Authors:

Lopez-Bezanilla, Alejandro ^[1]; Littlewood, Peter B. ^[2]

---

+ Show Author Affiliations

1. Argonne National Lab. (ANL), Argonne, IL (United States)
2. Argonne National Lab. (ANL), Argonne, IL (United States); Univ. of Chicago, IL (United States). James Franck Inst.

Publication Date:

Wed Jun 15 00:00:00 EDT 2016

Research Org.:

Argonne National Lab. (ANL), Argonne, IL (United States)

Sponsoring Org.:

USDOE Office of Science (SC), Basic Energy Sciences (BES)

OSTI Identifier:

1352652

Alternate Identifier(s):

OSTI ID: 1257495

Grant/Contract Number:  

AC02-06CH11357; FWP 70081

Resource Type:

Accepted Manuscript

Journal Name:

Physical Review B

Additional Journal Information:

Journal Volume: 93; Journal Issue: 24; Journal ID: ISSN 2469-9950

Publisher:

American Physical Society (APS)

Country of Publication:

United States

Language:

English

Subject:

36 MATERIALS SCIENCE