Vacancies in graphene: Dirac physics and fractional vacuum charges

Omrie Ovdat, Yaroslav Don, and Eric Akkermans
Phys. Rev. B 102, 075109 – Published 7 August 2020
PDFHTMLExport Citation

Abstract

The study of vacancies in graphene is a topic of growing interest. A single vacancy induces a localized stable charge of order unity interacting with other charges of the conductor through an unscreened Coulomb potential. It also breaks the symmetry between the two triangular graphene sublattices hence inducing zero energy states at the Dirac points. Here we show the fractional and pseudoscalar nature of this vacancy charge. A continuous Dirac model is presented which relates zero modes to vacuum fractional charge and to a parity anomaly. This relation constitutes an index theorem and is achieved by using particular chiral boundary conditions, which map the vacancy problem onto edge state physics. Vacancies in graphene thus allow us to realize prominent features of 2+1 quantum electrodynamics but without coupling to a gauge field. This essential difference makes vacancy physics relatively easy to implement and an interesting playground for topological state switching.

  • Figure
  • Figure
  • Figure
  • Figure
  • Received 13 September 2018
  • Revised 12 March 2019
  • Accepted 14 July 2020

DOI:https://doi.org/10.1103/PhysRevB.102.075109

©2020 American Physical Society

Physics Subject Headings (PhySH)

  1. Physical Systems
Condensed Matter, Materials & Applied Physics

Authors & Affiliations

Omrie Ovdat, Yaroslav Don, and Eric Akkermans*

  • Department of Physics, Technion – Israel Institute of Technology, Haifa 3200003, Israel

  • *eric@physics.technion.ac.il

Article Text (Subscription Required)

Click to Expand

Supplemental Material (Subscription Required)

Click to Expand

References (Subscription Required)

Click to Expand
Issue

Vol. 102, Iss. 7 — 15 August 2020

Reuse & Permissions
Access Options
Author publication services for translation and copyediting assistance advertisement

Authorization Required


×
×

Images

×

Sign up to receive regular email alerts from Physical Review B

Log In

Cancel
×

Search


Article Lookup

Paste a citation or DOI

Enter a citation
×