Unusual magnetotransport in twisted bilayer graphene

Journal Article · Mon Apr 11 00:00:00 EDT 2022 · Proceedings of the National Academy of Sciences of the United States of America

DOI:https://doi.org/10.1073/pnas.2118482119· OSTI ID:1862869

Finney, Joe ^[1]; Sharpe, Aaron L. ^[2]; Fox, Eli J. ^[1]; Hsueh, Connie L. ^[2]; Parker, Daniel E. ^[3]; Yankowitz, Matthew ^[4]; Chen, Shaowen ^[5]; Watanabe, Kenji ^[6]; Taniguchi, Takashi ^[7]; Dean, Cory R. ^[8]; Vishwanath, Ashvin ^[3]; Kastner, M. A. ^[9]; Goldhaber-Gordon, David ^[1]

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1. Department of Physics, Stanford University, Stanford, CA 94305, Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, CA 94025
2. Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, Department of Applied Physics, Stanford University, Stanford, CA 94305
3. Department of Physics, Harvard University, Cambridge, MA 02138
4. Department of Physics, University of Washington, Seattle, WA 98195, Department of Materials Science and Engineering, University of Washington, Seattle, WA 98195
5. Department of Physics, Harvard University, Cambridge, MA 02138, Department of Physics, Columbia University, New York, NY 10027, Department of Applied Physics and Applied Mathematics, Columbia University, New York, NY 10027
6. Research Center for Functional Materials, National Institute for Materials Science, Tsukuba 305-0044, Japan
7. International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Tsukuba 305-0044, Japan
8. Department of Physics, Columbia University, New York, NY 10027
9. Department of Physics, Stanford University, Stanford, CA 94305, Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139

Significance

When two sheets of graphene are twisted to the magic angle of 1.1 ^∘ , the resulting flat moiré bands can host exotic correlated electronic states such as superconductivity and ferromagnetism. Here, we show transport properties of a twisted bilayer graphene device at 1.38 ^∘ , far enough above the magic angle that we do not expect exotic correlated states. Instead, we see several unusual behaviors in the device’s resistivity upon tuning both charge carrier density and perpendicular magnetic field. We can reproduce these behaviors with a surprisingly simple model based on Hofstadter’s butterfly. These results shed light on the underlying properties of twisted bilayer graphene.

• Research Organization: Columbia Univ., New York, NY (United States); Stanford Univ., CA (United States)
• Sponsoring Organization: Gordon and Betty Moore Foundation; National Science Foundation (NSF); USDOE; USDOE Office of Science (SC), Basic Energy Sciences (BES). Materials Sciences & Engineering Division (MSE)
• Grant/Contract Number: AC02-76SF00515; SC0019443
• OSTI ID: 1862869
• Alternate ID(s): OSTI ID: 1904324
• Journal Information: Proceedings of the National Academy of Sciences of the United States of America, Journal Name: Proceedings of the National Academy of Sciences of the United States of America Journal Issue: 16 Vol. 119; ISSN 0027-8424
• Publisher: Proceedings of the National Academy of Sciences
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
Hofstadter’s butterfly
anisotropy
physical sciences
physics
twisted bilayer graphene