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Rosen IT, Andersen MP, Rodenbach LK, Tai L, Zhang P, Wang KL, Kastner MA, Goldhaber-Gordon D. Measured Potential Profile in a Quantum Anomalous Hall System Suggests Bulk-Dominated Current Flow. PHYSICAL REVIEW LETTERS 2022; 129:246602. [PMID: 36563259 DOI: 10.1103/physrevlett.129.246602] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Revised: 09/20/2022] [Accepted: 11/04/2022] [Indexed: 06/17/2023]
Abstract
Ideally, quantum anomalous Hall systems should display zero longitudinal resistance. Yet in experimental quantum anomalous Hall systems elevated temperature can make the longitudinal resistance finite, indicating dissipative flow of electrons. Here, we show that the measured potentials at multiple locations within a device at elevated temperature are well described by solution of Laplace's equation, assuming spatially uniform conductivity, suggesting nonequilibrium current flows through the two-dimensional bulk. Extrapolation suggests that at even lower temperatures current may still flow primarily through the bulk rather than, as had been assumed, through edge modes. An argument for bulk current flow previously applied to quantum Hall systems supports this picture.
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Affiliation(s)
- Ilan T Rosen
- Department of Applied Physics, Stanford University, Stanford, California 94305, USA
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Molly P Andersen
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
- Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, USA
| | - Linsey K Rodenbach
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
- Department of Physics, Stanford University, Stanford, California 94305, USA
| | - Lixuan Tai
- Department of Electrical Engineering, University of California, Los Angeles, California 90095, USA
| | - Peng Zhang
- Department of Electrical Engineering, University of California, Los Angeles, California 90095, USA
| | - Kang L Wang
- Department of Electrical Engineering, University of California, Los Angeles, California 90095, USA
| | - M A Kastner
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
- Department of Physics, Stanford University, Stanford, California 94305, USA
- Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - David Goldhaber-Gordon
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
- Department of Physics, Stanford University, Stanford, California 94305, USA
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Affiliation(s)
- Markus Büttiker
- The author is in the Département de Physique Théorique, Université de Genève, CH-1211 Geneva 4, Switzerland
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Machida T, Hirai H, Komiyama S, Shiraki Y. Size-dependent transmission coefficients of edge channels in the quantum-Hall regime. PHYSICAL REVIEW. B, CONDENSED MATTER 1996; 54:16860-16863. [PMID: 9985815 DOI: 10.1103/physrevb.54.16860] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Machida T, Hirai H, Komiyama S, Osada T, Shiraki Y. Current-induced decoupling of edge states in the integer quantum Hall effect. PHYSICAL REVIEW. B, CONDENSED MATTER 1996; 54:R14261-R14264. [PMID: 9985502 DOI: 10.1103/physrevb.54.r14261] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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