Energy Gaps and Layer Polarization of Integer and Fractional Quantum Hall States in Bilayer Graphene

Yanmeng Shi, Yongjin Lee, Shi Che, Ziqi Pi, Timothy Espiritu, Petr Stepanov, Dmitry Smirnov, Chun Ning Lau, and Fan Zhang
Phys. Rev. Lett. 116, 056601 – Published 5 February 2016
PDFHTMLExport Citation

Abstract

Owing to the spin, valley, and orbital symmetries, the lowest Landau level in bilayer graphene exhibits multicomponent quantum Hall ferromagnetism. Using transport spectroscopy, we investigate the energy gaps of integer and fractional quantum Hall (QH) states in bilayer graphene with controlled layer polarization. The state at filling factor ν=1 has two distinct phases: a layer polarized state that has a larger energy gap and is stabilized by high electric field, and a hitherto unobserved interlayer coherent state with a smaller gap that is stabilized by large magnetic field. In contrast, the ν=2/3 quantum Hall state and a feature at ν=1/2 are only resolved at finite electric field and large magnetic field. These results underscore the importance of controlling layer polarization in understanding the competing symmetries in the unusual QH system of BLG.

  • Figure
  • Figure
  • Figure
  • Figure
  • Received 20 October 2015

DOI:https://doi.org/10.1103/PhysRevLett.116.056601

© 2016 American Physical Society

Physics Subject Headings (PhySH)

Condensed Matter, Materials & Applied Physics

Authors & Affiliations

Yanmeng Shi1, Yongjin Lee1, Shi Che1, Ziqi Pi1, Timothy Espiritu1, Petr Stepanov1, Dmitry Smirnov2, Chun Ning Lau1,*, and Fan Zhang3,†

  • 1Department of Physics and Astronomy, University of California, Riverside, Riverside, California 91765, USA
  • 2National High Magnetic Field Laboratory, Tallahassee, Florida 32310, USA
  • 3Department of Physics, University of Texas at Dallas, Richardson, Texas 75080, USA

  • *lau@physics.ucr.edu
  • Zhang@utdallas.edu

Article Text (Subscription Required)

Click to Expand

Supplemental Material (Subscription Required)

Click to Expand

References (Subscription Required)

Click to Expand
Issue

Vol. 116, Iss. 5 — 5 February 2016

Reuse & Permissions
Access Options
CHORUS

Article Available via CHORUS

Download Accepted Manuscript
Author publication services for translation and copyediting assistance advertisement

Authorization Required


×
×

Images

×

Sign up to receive regular email alerts from Physical Review Letters

Log In

Cancel
×

Search


Article Lookup

Paste a citation or DOI

Enter a citation
×