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Vaitiekėnas S, Winkler GW, van Heck B, Karzig T, Deng MT, Flensberg K, Glazman LI, Nayak C, Krogstrup P, Lutchyn RM, Marcus CM. Flux-induced topological superconductivity in full-shell nanowires. Science 2020; 367:367/6485/eaav3392. [DOI: 10.1126/science.aav3392] [Citation(s) in RCA: 90] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Revised: 08/04/2019] [Accepted: 02/27/2020] [Indexed: 11/02/2022]
Abstract
Hybrid semiconductor-superconductor nanowires have emerged as a promising platform for realizing topological superconductivity (TSC). Here, we present a route to TSC using magnetic flux applied to a full superconducting shell surrounding a semiconducting nanowire core. Tunneling into the core reveals a hard induced gap near zero applied flux, corresponding to zero phase winding, and a gapped region with a discrete zero-energy state around one applied flux quantum, corresponding to 2π phase winding. Theoretical analysis indicates that the winding of the superconducting phase can induce a transition to a topological phase supporting Majorana zero modes. Measured Coulomb blockade peak spacing around one flux quantum shows a length dependence that is consistent with the existence of Majorana modes at the ends of the nanowire.
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Affiliation(s)
- S. Vaitiekėnas
- Center for Quantum Devices and Microsoft Quantum Lab–Copenhagen, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
| | - G. W. Winkler
- Microsoft Quantum, Microsoft Station Q, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - B. van Heck
- Microsoft Quantum, Microsoft Station Q, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - T. Karzig
- Microsoft Quantum, Microsoft Station Q, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - M.-T. Deng
- Center for Quantum Devices and Microsoft Quantum Lab–Copenhagen, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
| | - K. Flensberg
- Center for Quantum Devices and Microsoft Quantum Lab–Copenhagen, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
| | - L. I. Glazman
- Departments of Physics and Applied Physics, Yale University, New Haven, CT 06520, USA
| | - C. Nayak
- Microsoft Quantum, Microsoft Station Q, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - P. Krogstrup
- Center for Quantum Devices and Microsoft Quantum Lab–Copenhagen, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
| | - R. M. Lutchyn
- Microsoft Quantum, Microsoft Station Q, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - C. M. Marcus
- Center for Quantum Devices and Microsoft Quantum Lab–Copenhagen, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
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Vaitiekėnas S, Whiticar AM, Deng MT, Krizek F, Sestoft JE, Palmstrøm CJ, Marti-Sanchez S, Arbiol J, Krogstrup P, Casparis L, Marcus CM. Selective-Area-Grown Semiconductor-Superconductor Hybrids: A Basis for Topological Networks. Phys Rev Lett 2018; 121:147701. [PMID: 30339420 DOI: 10.1103/physrevlett.121.147701] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2018] [Revised: 06/20/2018] [Indexed: 06/08/2023]
Abstract
We introduce selective area grown hybrid InAs/Al nanowires based on molecular beam epitaxy, allowing arbitrary semiconductor-superconductor networks containing loops and branches. Transport reveals a hard induced gap and unpoisoned 2e-periodic Coulomb blockade, with temperature dependent 1e features in agreement with theory. Coulomb peak spacing in parallel magnetic field displays overshoot, indicating an oscillating discrete near-zero subgap state consistent with device length. Finally, we investigate a loop network, finding strong spin-orbit coupling and a coherence length of several microns. These results demonstrate the potential of this platform for scalable topological networks among other applications.
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Affiliation(s)
- S Vaitiekėnas
- Center for Quantum Devices and Station Q Copenhagen, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | - A M Whiticar
- Center for Quantum Devices and Station Q Copenhagen, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | - M-T Deng
- Center for Quantum Devices and Station Q Copenhagen, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | - F Krizek
- Center for Quantum Devices and Station Q Copenhagen, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | - J E Sestoft
- Center for Quantum Devices and Station Q Copenhagen, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | - C J Palmstrøm
- Materials Department, University of California, Santa Barbara, California 93106, USA
| | - S Marti-Sanchez
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST, Campus UAB, 08193 Bellaterra, Barcelona, Spain
| | - J Arbiol
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST, Campus UAB, 08193 Bellaterra, Barcelona, Spain
- ICREA, Pg. Lluís Companys 23, 08010 Barcelona, Catalonia, Spain
| | - P Krogstrup
- Center for Quantum Devices and Station Q Copenhagen, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | - L Casparis
- Center for Quantum Devices and Station Q Copenhagen, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | - C M Marcus
- Center for Quantum Devices and Station Q Copenhagen, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
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Vaitiekėnas S, Deng MT, Nygård J, Krogstrup P, Marcus CM. Effective g Factor of Subgap States in Hybrid Nanowires. Phys Rev Lett 2018; 121:037703. [PMID: 30085813 DOI: 10.1103/physrevlett.121.037703] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Revised: 12/16/2017] [Indexed: 06/08/2023]
Abstract
We use the effective g factor of Andreev subgap states in an axial magnetic field to investigate how the superconducting density of states is distributed between the semiconductor core and the superconducting shell in hybrid nanowires. We find a steplike reduction of the Andreev g factor and an improved hard gap with reduced carrier density in the nanowire, controlled by gate voltage. These observations are relevant for Majorana devices, which require tunable carrier density and a g factor exceeding that of the parent superconductor.
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Affiliation(s)
- S Vaitiekėnas
- Center for Quantum Devices and Station Q Copenhagen, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | - M-T Deng
- Center for Quantum Devices and Station Q Copenhagen, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | - J Nygård
- Center for Quantum Devices and Station Q Copenhagen, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | - P Krogstrup
- Center for Quantum Devices and Station Q Copenhagen, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | - C M Marcus
- Center for Quantum Devices and Station Q Copenhagen, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
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Deng MT, Vaitiekėnas S, Hansen EB, Danon J, Leijnse M, Flensberg K, Nygård J, Krogstrup P, Marcus CM. Majorana bound state in a coupled quantum-dot hybrid-nanowire system. Science 2016; 354:1557-1562. [DOI: 10.1126/science.aaf3961] [Citation(s) in RCA: 687] [Impact Index Per Article: 85.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Accepted: 11/16/2016] [Indexed: 11/02/2022]
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