Gate-defined wires in twisted bilayer graphene: From electrical detection of intervalley coherence to internally engineered Majorana modes
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1.
California Institute of Technology
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2.
University of California, Davis
Abstract
Twisted bilayer graphene (TBG) realizes a highly tunable, strongly interacting system featuring superconductivity and various correlated insulating states. We establish gate-defined wires in TBG with proximity-induced spin-orbit coupling as (i) a tool for revealing the nature of correlated insulators and (ii) a platform for Majorana-based topological qubits. We show that the band structure of a gate-defined wire immersed in an intervalley coherent correlated insulator inherits electrically detectable fingerprints of symmetry breaking native to the latter. Surrounding the wire by a superconducting TBG region on one side and an intervalley coherent correlated insulator on the other further enables the formation of Majorana zero modes—possibly even at zero magnetic field depending on the precise symmetry-breaking order present. Our proposal not only introduces a highly gate-tunable topological qubit medium relying on internally generated proximity effects but can also shed light on the Cooper-pairing mechanism in TBG.
Additional Information
© 2022 American Physical Society. Received 22 June 2021; revised 3 November 2021; accepted 10 January 2022; published 9 February 2022. We are grateful to Cory Dean, Ethan Lake, Cyprian Lewandowski, T. Senthil, and Andrea Young for illuminating discussions. This paper was supported by the Army Research Office under Grant Award No. W911NF17- 1-0323; the U.S. Department of Energy, Office of Science, National Quantum Information Science Research Centers, Quantum Science Center; the National Science Foundation through Grant No. DMR-1723367; an Aker Scholarship; the Caltech Institute for Quantum Information and Matter, an NSF Physics Frontiers Center with support of the Gordon and Betty Moore Foundation through Grant No. GBMF1250; and the Walter Burke Institute for Theoretical Physics at Caltech. A.T. and I.M.S. contributed equally to this paper.Attached Files
Published - PhysRevB.105.L081405.pdf
Submitted - 2105.02891.pdf
Supplemental Material - TBG_Majorana_Suppl.pdf
Files
2105.02891.pdf
Additional details
Additional titles
- Alternative title
- Gate-defined wires in twisted bilayer graphene: from electrical detection of inter-valley coherence to internally engineered Majorana modes
Identifiers
- Eprint ID
- 112701
- Resolver ID
- CaltechAUTHORS:20220104-233136449
Related works
- Describes
- https://arxiv.org/abs/2105.02891 (URL)
Funding
- Army Research Office (ARO)
- W911NF17-1-0323
- Department of Energy (DOE)
- NSF
- DMR-1723367
- Aker Scholarship Foundation
- Institute for Quantum Information and Matter (IQIM)
- Gordon and Betty Moore Foundation
- GBMF1250
- Walter Burke Institute for Theoretical Physics, Caltech
Dates
- Created
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2022-01-05Created from EPrint's datestamp field
- Updated
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2023-03-15Created from EPrint's last_modified field