1
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Goswami A, Mudi SR, Dempsey C, Zhang P, Wu H, Zhang B, Mitchell WJ, Lee JS, Frolov SM, Palmstrøm CJ. Sn/InAs Josephson Junctions on Selective Area Grown Nanowires with in Situ Shadowed Superconductor Evaporation. NANO LETTERS 2023; 23:7311-7318. [PMID: 37561818 DOI: 10.1021/acs.nanolett.3c01320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/12/2023]
Abstract
Superconductor-semiconductor nanowire hybrid structures are useful in fabricating devices for quantum information processing. While selective area growth (SAG) offers the flexibility to grow semiconductor nanowires in arbitrary geometries, in situ evaporation of superconductors ensures pristine superconductor-semiconductor interfaces, resulting in strong induced superconductivity in the semiconducting nanowire. In this work, we used high-aspect-ratio SiOx dielectric walls to in situ evaporate islands of superconductor tin on in-plane InAs SAG nanowires. Our technique enables customization in the designs of such hybrid nanostructures, while simultaneously performing the nanowire and superconductor growth without breaking vacuum. Using this technique, we grew super(S)-normal(N)-super(S), NS, and SNSNS junctions. We performed cryogenic electron transport measurements revealing the presence of gate and field tunable supercurrents. We further measured the superconducting gap and critical fields in the hybrid nanostructures and the crossover from 2e to 1e periodicity in the SNSNS junctions as a proof of the usability of these hybrid nanostructures.
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Affiliation(s)
- Aranya Goswami
- Electrical and Computer Engineering Department, University of California, Santa Barbara, Santa Barbara, California 93106, United States
| | - Sanchayeta R Mudi
- Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Connor Dempsey
- Electrical and Computer Engineering Department, University of California, Santa Barbara, Santa Barbara, California 93106, United States
| | - Po Zhang
- Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Hao Wu
- Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Bomin Zhang
- Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - William J Mitchell
- Nanofabrication facility, University of California, Santa Barbara, Santa Barbara, California 93106, United States
| | - Joon Sue Lee
- California NanoSystems Institute, University of California Santa Barbara, Santa Barbara, California 93106, United States
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Sergey M Frolov
- Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Christopher J Palmstrøm
- Electrical and Computer Engineering Department, University of California, Santa Barbara, Santa Barbara, California 93106, United States
- Materials Department, University of California, Santa Barbara, Santa Barbara, California 93106, United States
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2
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Stampfer L, Carrad DJ, Olsteins D, Petersen CEN, Khan SA, Krogstrup P, Jespersen TS. Andreev Interference in the Surface Accumulation Layer of Half-Shell InAsSb/Al Hybrid Nanowires. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022; 34:e2108878. [PMID: 35050545 DOI: 10.1002/adma.202108878] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Revised: 12/29/2021] [Indexed: 06/14/2023]
Abstract
Understanding the spatial distribution of charge carriers in III-V nanowires proximity coupled to superconductors is important for the design and interpretation of experiments based on hybrid quantum devices. In this letter, the gate-dependent surface accumulation layer of half-shell InAsSb/Al nanowires is studied by means of Andreev interference in a parallel magnetic field. Both uniform hybrid nanowires and devices featuring a short Josephson junction fabricated by shadow lithography, exhibit periodic modulation of the switching current. The period corresponds to a flux quantum through the nanowire diameter and is consistent with Andreev bound states occupying a cylindrical surface accumulation layer. The spatial distribution is tunable by a gate potential as expected from electrostatic models.
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Affiliation(s)
- Lukas Stampfer
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, Copenhagen, 2100, Denmark
| | - Damon J Carrad
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, Copenhagen, 2100, Denmark
| | - Dags Olsteins
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, Copenhagen, 2100, Denmark
| | - Christian E N Petersen
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, Copenhagen, 2100, Denmark
| | - Sabbir A Khan
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, Copenhagen, 2100, Denmark
- Microsoft Quantum Materials Lab Copenhagen, Lyngby, 2800, Denmark
| | - Peter Krogstrup
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, Copenhagen, 2100, Denmark
- Microsoft Quantum Materials Lab Copenhagen, Lyngby, 2800, Denmark
| | - Thomas S Jespersen
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, Copenhagen, 2100, Denmark
- Department of Energy Conversion and Storage, Technical University of Denmark, Fysikvej, Building 310, Lyngby, 2800, Denmark
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3
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Pendharkar M, Zhang B, Wu H, Zarassi A, Zhang P, Dempsey CP, Lee JS, Harrington SD, Badawy G, Gazibegovic S, Op Het Veld RLM, Rossi M, Jung J, Chen AH, Verheijen MA, Hocevar M, Bakkers EPAM, Palmstrøm CJ, Frolov SM. Parity-preserving and magnetic field-resilient superconductivity in InSb nanowires with Sn shells. Science 2021; 372:508-511. [PMID: 33858990 DOI: 10.1126/science.aba5211] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Accepted: 03/13/2021] [Indexed: 11/02/2022]
Abstract
Improving materials used to make qubits is crucial to further progress in quantum information processing. Of particular interest are semiconductor-superconductor heterostructures that are expected to form the basis of topological quantum computing. We grew semiconductor indium antimonide nanowires that were coated with shells of tin of uniform thickness. No interdiffusion was observed at the interface between Sn and InSb. Tunnel junctions were prepared by in situ shadowing. Despite the lack of lattice matching between Sn and InSb, a 15-nanometer-thick shell of tin was found to induce a hard superconducting gap, with superconductivity persisting in magnetic field up to 4 teslas. A small island of Sn-InSb exhibits the two-electron charging effect. These findings suggest a less restrictive approach to fabricating superconducting and topological quantum circuits.
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Affiliation(s)
- M Pendharkar
- Electrical and Computer Engineering, University of California, Santa Barbara, CA 93106, USA
| | - B Zhang
- Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - H Wu
- Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - A Zarassi
- Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - P Zhang
- Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - C P Dempsey
- Electrical and Computer Engineering, University of California, Santa Barbara, CA 93106, USA
| | - J S Lee
- California NanoSystems Institute, University of California, Santa Barbara, CA 93106, USA
| | - S D Harrington
- Materials Department, University of California, Santa Barbara, CA 93106, USA
| | - G Badawy
- Eindhoven University of Technology, 5600 MB Eindhoven, Netherlands
| | - S Gazibegovic
- Eindhoven University of Technology, 5600 MB Eindhoven, Netherlands
| | | | - M Rossi
- Eindhoven University of Technology, 5600 MB Eindhoven, Netherlands
| | - J Jung
- Eindhoven University of Technology, 5600 MB Eindhoven, Netherlands
| | - A-H Chen
- Univ. Grenoble Alpes, CNRS, Grenoble INP, Institut Néel, 38000 Grenoble, France
| | - M A Verheijen
- Eindhoven University of Technology, 5600 MB Eindhoven, Netherlands
| | - M Hocevar
- Univ. Grenoble Alpes, CNRS, Grenoble INP, Institut Néel, 38000 Grenoble, France
| | - E P A M Bakkers
- Eindhoven University of Technology, 5600 MB Eindhoven, Netherlands
| | - C J Palmstrøm
- Electrical and Computer Engineering, University of California, Santa Barbara, CA 93106, USA.,California NanoSystems Institute, University of California, Santa Barbara, CA 93106, USA.,Materials Department, University of California, Santa Barbara, CA 93106, USA
| | - S M Frolov
- Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, PA 15260, USA.
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4
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Perla P, Fonseka HA, Zellekens P, Deacon R, Han Y, Kölzer J, Mörstedt T, Bennemann B, Espiari A, Ishibashi K, Grützmacher D, Sanchez AM, Lepsa MI, Schäpers T. Fully in situ Nb/InAs-nanowire Josephson junctions by selective-area growth and shadow evaporation. NANOSCALE ADVANCES 2021; 3:1413-1421. [PMID: 36132855 PMCID: PMC9418346 DOI: 10.1039/d0na00999g] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Accepted: 01/17/2021] [Indexed: 06/14/2023]
Abstract
Josephson junctions based on InAs semiconducting nanowires and Nb superconducting electrodes are fabricated in situ by a special shadow evaporation scheme for the superconductor electrode. Compared to other metallic superconductors such as Al, Nb has the advantage of a larger superconducting gap which allows operation at higher temperatures and magnetic fields. Our junctions are fabricated by shadow evaporation of Nb on pairs of InAs nanowires grown selectively on two adjacent tilted Si (111) facets and crossing each other at a small distance. The upper wire relative to the deposition source acts as a shadow mask determining the gap of the superconducting electrodes on the lower nanowire. Electron microscopy measurements show that the fully in situ fabrication method gives a clean InAs/Nb interface. A clear Josephson supercurrent is observed in the current-voltage characteristics, which can be controlled by a bottom gate. The large excess current indicates a high junction transparency. Under microwave radiation, pronounced integer Shapiro steps are observed suggesting a sinusoidal current-phase relation. Owing to the large critical field of Nb, the Josephson supercurrent can be maintained to magnetic fields exceeding 1 T. Our results show that in situ prepared Nb/InAs nanowire contacts are very interesting candidates for superconducting quantum circuits requiring large magnetic fields.
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Affiliation(s)
- Pujitha Perla
- Peter Grünberg Institut (PGI-9), Forschungszentrum Jülich 52425 Jülich Germany +49 2461 61 2940 +49 2461 61 2668
- JARA-Fundamentals of Future Information Technology, Jülich-Aachen Research Alliance, Forschungszentrum Jülich, RWTH Aachen University Germany
| | - H Aruni Fonseka
- Department of Physics, University of Warwick Coventry CV4 7AL UK
| | - Patrick Zellekens
- Peter Grünberg Institut (PGI-9), Forschungszentrum Jülich 52425 Jülich Germany +49 2461 61 2940 +49 2461 61 2668
- JARA-Fundamentals of Future Information Technology, Jülich-Aachen Research Alliance, Forschungszentrum Jülich, RWTH Aachen University Germany
| | - Russell Deacon
- RIKEN Center for Emergent Matter Science and Advanced Device Laboratory 351-0198 Saitama Japan
| | - Yisong Han
- Department of Physics, University of Warwick Coventry CV4 7AL UK
| | - Jonas Kölzer
- Peter Grünberg Institut (PGI-9), Forschungszentrum Jülich 52425 Jülich Germany +49 2461 61 2940 +49 2461 61 2668
- JARA-Fundamentals of Future Information Technology, Jülich-Aachen Research Alliance, Forschungszentrum Jülich, RWTH Aachen University Germany
| | - Timm Mörstedt
- Peter Grünberg Institut (PGI-9), Forschungszentrum Jülich 52425 Jülich Germany +49 2461 61 2940 +49 2461 61 2668
- JARA-Fundamentals of Future Information Technology, Jülich-Aachen Research Alliance, Forschungszentrum Jülich, RWTH Aachen University Germany
| | - Benjamin Bennemann
- Peter Grünberg Institut (PGI-9), Forschungszentrum Jülich 52425 Jülich Germany +49 2461 61 2940 +49 2461 61 2668
- JARA-Fundamentals of Future Information Technology, Jülich-Aachen Research Alliance, Forschungszentrum Jülich, RWTH Aachen University Germany
| | - Abbas Espiari
- Peter Grünberg Institut (PGI-9), Forschungszentrum Jülich 52425 Jülich Germany +49 2461 61 2940 +49 2461 61 2668
- JARA-Fundamentals of Future Information Technology, Jülich-Aachen Research Alliance, Forschungszentrum Jülich, RWTH Aachen University Germany
| | - Koji Ishibashi
- RIKEN Center for Emergent Matter Science and Advanced Device Laboratory 351-0198 Saitama Japan
| | - Detlev Grützmacher
- Peter Grünberg Institut (PGI-9), Forschungszentrum Jülich 52425 Jülich Germany +49 2461 61 2940 +49 2461 61 2668
- JARA-Fundamentals of Future Information Technology, Jülich-Aachen Research Alliance, Forschungszentrum Jülich, RWTH Aachen University Germany
- Peter Grünberg Institut (PGI-10), Forschungszentrum Jülich 52425 Jülich Germany
| | - Ana M Sanchez
- Department of Physics, University of Warwick Coventry CV4 7AL UK
| | - Mihail Ion Lepsa
- JARA-Fundamentals of Future Information Technology, Jülich-Aachen Research Alliance, Forschungszentrum Jülich, RWTH Aachen University Germany
- Peter Grünberg Institut (PGI-10), Forschungszentrum Jülich 52425 Jülich Germany
| | - Thomas Schäpers
- Peter Grünberg Institut (PGI-9), Forschungszentrum Jülich 52425 Jülich Germany +49 2461 61 2940 +49 2461 61 2668
- JARA-Fundamentals of Future Information Technology, Jülich-Aachen Research Alliance, Forschungszentrum Jülich, RWTH Aachen University Germany
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5
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Kringhøj A, Winkler GW, Larsen TW, Sabonis D, Erlandsson O, Krogstrup P, van Heck B, Petersson KD, Marcus CM. Andreev Modes from Phase Winding in a Full-Shell Nanowire-Based Transmon. PHYSICAL REVIEW LETTERS 2021; 126:047701. [PMID: 33576664 DOI: 10.1103/physrevlett.126.047701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2020] [Accepted: 01/07/2021] [Indexed: 06/12/2023]
Abstract
We investigate transmon qubits made from semiconductor nanowires with a fully surrounding superconducting shell. In the regime of reentrant superconductivity associated with the destructive Little-Parks effect, numerous coherent transitions are observed in the first reentrant lobe, where the shell carries 2π winding of superconducting phase, and are absent in the zeroth lobe. As junction density was increased by gate voltage, qubit coherence was suppressed then lost in the first lobe. These observations and numerical simulations highlight the role of winding-induced Andreev states in the junction.
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Affiliation(s)
- A Kringhøj
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
- Microsoft Quantum Lab-Copenhagen, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
| | - G W Winkler
- Microsoft Quantum, Station Q, University of California, Santa Barbara, California 93106-6105, USA
| | - T W Larsen
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
- Microsoft Quantum Lab-Copenhagen, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
| | - D Sabonis
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
- Microsoft Quantum Lab-Copenhagen, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
| | - O Erlandsson
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
- Microsoft Quantum Lab-Copenhagen, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
| | - P Krogstrup
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
- Microsoft Quantum Materials Lab-Copenhagen, 2800 Lyngby, Denmark
| | - B van Heck
- Microsoft Quantum Lab Delft, Delft University of Technology, 2600 GA Delft, Netherlands
| | - K D Petersson
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
- Microsoft Quantum Lab-Copenhagen, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
| | - C M Marcus
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
- Microsoft Quantum Lab-Copenhagen, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
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6
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Li CZ, Wang AQ, Li C, Zheng WZ, Brinkman A, Yu DP, Liao ZM. Topological Transition of Superconductivity in Dirac Semimetal Nanowire Josephson Junctions. PHYSICAL REVIEW LETTERS 2021; 126:027001. [PMID: 33512215 DOI: 10.1103/physrevlett.126.027001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Accepted: 12/18/2020] [Indexed: 06/12/2023]
Abstract
We report the topological transition by gate control in a Cd_{3}As_{2} Dirac semimetal nanowire Josephson junction with diameter of about 64 nm. In the electron branch, the quantum confinement effect enforces the surface band into a series of gapped subbands and thus nontopological states. In the hole branch, however, because the hole mean free path is smaller than the nanowire perimeter, the quantum confinement effect is inoperative and the topological property maintained. The superconductivity is enhanced by gate tuning from electron to hole conduction, manifested by a larger critical supercurrent and a larger critical magnetic field, which is attributed to the topological transition from gapped surface subbands to a gapless surface band. The gate-controlled topological transition of superconductivity should be valuable for manipulation of Majorana zero modes, providing a platform for future compatible and scalable design of topological qubits.
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Affiliation(s)
- Cai-Zhen Li
- Shenzhen Institute for Quantum Science and Engineering, and Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, Beijing 100871, China
| | - An-Qi Wang
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, Beijing 100871, China
- Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China
| | - Chuan Li
- MESA+ Institute for Nanotechnology, University of Twente, 7500 AE Enschede, The Netherlands
| | - Wen-Zhuang Zheng
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, Beijing 100871, China
| | - Alexander Brinkman
- MESA+ Institute for Nanotechnology, University of Twente, 7500 AE Enschede, The Netherlands
| | - Da-Peng Yu
- Shenzhen Institute for Quantum Science and Engineering, and Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China
| | - Zhi-Min Liao
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, Beijing 100871, China
- Beijing Key Laboratory of Quantum Devices, Peking University, Beijing 100871, China
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7
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Wakamura T, Wu NJ, Chepelianskii AD, Guéron S, Och M, Ferrier M, Taniguchi T, Watanabe K, Mattevi C, Bouchiat H. Spin-Orbit-Enhanced Robustness of Supercurrent in Graphene/WS_{2} Josephson Junctions. PHYSICAL REVIEW LETTERS 2020; 125:266801. [PMID: 33449709 DOI: 10.1103/physrevlett.125.266801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Accepted: 11/16/2020] [Indexed: 06/12/2023]
Abstract
We demonstrate the enhanced robustness of the supercurrent through graphene-based Josephson junctions in which strong spin-orbit interactions (SOIs) are induced. We compare the persistence of a supercurrent at high out-of-plane magnetic fields between Josephson junctions with graphene on hexagonal boron-nitride and graphene on WS_{2}, where strong SOIs are induced via the proximity effect. We find that in the shortest junctions both systems display signatures of induced superconductivity, characterized by a suppressed differential resistance at a low current, in magnetic fields up to 1 T. In longer junctions, however, only graphene on WS_{2} exhibits induced superconductivity features in such high magnetic fields, and they even persist up to 7 T. We argue that these robust superconducting signatures arise from quasiballistic edge states stabilized by the strong SOIs induced in graphene by WS_{2}.
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Affiliation(s)
- T Wakamura
- Université Paris-Saclay, CNRS, Laboratoire de Physique des Solides, 91405, Orsay, France
| | - N J Wu
- Université Paris-Saclay, CNRS, Laboratoire de Physique des Solides, 91405, Orsay, France
- Université Paris-Saclay, CNRS, Institut des Sciences Moléculaires d'Orsay, 91405, Orsay, France
| | - A D Chepelianskii
- Université Paris-Saclay, CNRS, Laboratoire de Physique des Solides, 91405, Orsay, France
| | - S Guéron
- Université Paris-Saclay, CNRS, Laboratoire de Physique des Solides, 91405, Orsay, France
| | - M Och
- Department of Materials, Imperial College London, Exhibition Road, London SW7 2AZ, United Kingdom
| | - M Ferrier
- Université Paris-Saclay, CNRS, Laboratoire de Physique des Solides, 91405, Orsay, France
| | - T Taniguchi
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - K Watanabe
- Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - C Mattevi
- Department of Materials, Imperial College London, Exhibition Road, London SW7 2AZ, United Kingdom
| | - H Bouchiat
- Université Paris-Saclay, CNRS, Laboratoire de Physique des Solides, 91405, Orsay, France
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8
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Kringhøj A, Larsen TW, van Heck B, Sabonis D, Erlandsson O, Petkovic I, Pikulin DI, Krogstrup P, Petersson KD, Marcus CM. Controlled dc Monitoring of a Superconducting Qubit. PHYSICAL REVIEW LETTERS 2020; 124:056801. [PMID: 32083909 DOI: 10.1103/physrevlett.124.056801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Accepted: 12/23/2019] [Indexed: 06/10/2023]
Abstract
Creating a transmon qubit using semiconductor-superconductor hybrid materials not only provides electrostatic control of the qubit frequency, it also allows parts of the circuit to be electrically connected and disconnected in situ by operating a semiconductor region of the device as a field-effect transistor. Here, we exploit this feature to compare in the same device characteristics of the qubit, such as frequency and relaxation time, with related transport properties such as critical supercurrent and normal-state resistance. Gradually opening the field-effect transistor to the monitoring circuit allows the influence of weak-to-strong dc monitoring of a "live" qubit to be measured. A model of this influence yields excellent agreement with experiment, demonstrating a relaxation rate mediated by a gate-controlled environmental coupling.
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Affiliation(s)
- A Kringhøj
- Microsoft Quantum Lab Copenhagen and Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | - T W Larsen
- Microsoft Quantum Lab Copenhagen and Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | - B van Heck
- Microsoft Quantum, Station Q, University of California, Santa Barbara, California 93106-6105, USA
- Microsoft Quantum Lab Delft, Delft University of Technology, 2600 GA Delft, Netherlands
| | - D Sabonis
- Microsoft Quantum Lab Copenhagen and Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | - O Erlandsson
- Microsoft Quantum Lab Copenhagen and Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | - I Petkovic
- Microsoft Quantum Lab Copenhagen and Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | - D I Pikulin
- Microsoft Quantum, Station Q, University of California, Santa Barbara, California 93106-6105, USA
| | - P Krogstrup
- Microsoft Quantum Lab Copenhagen and Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
- Microsoft Quantum Materials Lab Copenhagen, Kanalvej 7, 2800 Lyngby, Denmark
| | - K D Petersson
- Microsoft Quantum Lab Copenhagen and Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | - C M Marcus
- Microsoft Quantum Lab Copenhagen and Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
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9
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Awoga OA, Cayao J, Black-Schaffer AM. Supercurrent Detection of Topologically Trivial Zero-Energy States in Nanowire Junctions. PHYSICAL REVIEW LETTERS 2019; 123:117001. [PMID: 31573272 DOI: 10.1103/physrevlett.123.117001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Indexed: 06/10/2023]
Abstract
We report the emergence of zero-energy states in the trivial phase of a short nanowire junction with a strong spin-orbit coupling and magnetic field, formed by strong coupling between the nanowire and two superconductors. The zero-energy states appear in the junction when the superconductors induce a large energy shift in the nanowire, such that the junction naturally forms a quantum dot, a process that is highly tunable by the superconductor width. Most importantly, we demonstrate that the zero-energy states produce a π shift in the phase-biased supercurrent, which can be used as a simple tool for their unambiguous detection, ruling out any Majorana-like interpretation.
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Affiliation(s)
- Oladunjoye A Awoga
- Department of Physics and Astronomy, Uppsala University, Box 516, S-751 20 Uppsala, Sweden
| | - Jorge Cayao
- Department of Physics and Astronomy, Uppsala University, Box 516, S-751 20 Uppsala, Sweden
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10
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Chen J, Woods BD, Yu P, Hocevar M, Car D, Plissard SR, Bakkers EPAM, Stanescu TD, Frolov SM. Ubiquitous Non-Majorana Zero-Bias Conductance Peaks in Nanowire Devices. PHYSICAL REVIEW LETTERS 2019; 123:107703. [PMID: 31573319 DOI: 10.1103/physrevlett.123.107703] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Indexed: 06/10/2023]
Abstract
We perform tunneling measurements on indium antimonide nanowire-superconductor hybrid devices fabricated for the studies of Majorana bound states. At finite magnetic field, resonances that strongly resemble Majorana bound states, including zero-bias pinning, become common to the point of ubiquity. Since Majorana bound states are predicted in only a limited parameter range in nanowire devices, we seek an alternative explanation for the observed zero-bias peaks. With the help of a self-consistent Poission-Schrödinger multiband model developed in parallel, we identify several families of trivial subgap states that overlap and interact, giving rise to a crowded spectrum near zero energy and zero-bias conductance peaks in experiments. These findings advance the search for Majorana bound states through improved understanding of broader phenomena found in superconductor-semiconductor systems.
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Affiliation(s)
- J Chen
- Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA
- Department of Electrical and Computer Engineering and Peterson Institute of NanoScience and Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, USA
| | - B D Woods
- Department of Physics and Astronomy, West Virginia University, Morgantown, West Virginia 26506, USA
| | - P Yu
- Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA
| | - M Hocevar
- Univ. Grenoble Alpes, CNRS, Grenoble INP, Institut Néel, 38000 Grenoble, France
| | - D Car
- Eindhoven University of Technology, 5600 MB, Eindhoven, Netherlands
| | - S R Plissard
- LAAS CNRS, Université de Toulouse, 31031 Toulouse, France
| | - E P A M Bakkers
- Eindhoven University of Technology, 5600 MB, Eindhoven, Netherlands
| | - T D Stanescu
- Department of Physics and Astronomy, West Virginia University, Morgantown, West Virginia 26506, USA
| | - S M Frolov
- Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA
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Estrada Saldaña JC, Žitko R, Cleuziou JP, Lee EJH, Zannier V, Ercolani D, Sorba L, Aguado R, De Franceschi S. Charge localization and reentrant superconductivity in a quasi-ballistic InAs nanowire coupled to superconductors. SCIENCE ADVANCES 2019; 5:eaav1235. [PMID: 31281880 PMCID: PMC6611689 DOI: 10.1126/sciadv.aav1235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Accepted: 05/29/2019] [Indexed: 06/09/2023]
Abstract
A semiconductor nanowire with strong spin-orbit coupling in proximity to a superconductor is predicted to display Majorana edge states emerging under a properly oriented magnetic field. The experimental investigation of these exotic states requires assessing the one-dimensional (1D) character of the nanowire and understanding the superconducting proximity effect in the presence of a magnetic field. Here, we explore the quasi-ballistic 1D transport regime of an InAs nanowire with Ta contacts. Fine-tuned by means of local gates, the observed plateaus of approximately quantized conductance hide the presence of a localized electron, giving rise to a lurking Coulomb blockade effect and Kondo physics. When Ta becomes superconducting, this local charge causes an unusual, reentrant magnetic field dependence of the supercurrent, which we ascribe to a 0 - π transition. Our results underline the relevant role of unintentional charge localization in the few-channel regime where helical subbands and Majorana quasi-particles are expected to arise.
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Affiliation(s)
| | - R. Žitko
- Jožef Stefan Institute, Jamova 39, Ljubljana, Slovenia
- Faculty of Mathematics and Physics, University of Ljubljana, Jadranska 19, Ljubljana, Slovenia
| | - J. P. Cleuziou
- Université Grenoble Alpes, CEA, INAC-PHELIQS, 38000 Grenoble, France
| | - E. J. H. Lee
- Université Grenoble Alpes, CEA, INAC-PHELIQS, 38000 Grenoble, France
| | - V. Zannier
- NEST–Istituto Nanoscienze–CNR and Scuola Normale Superiore, Piazza S. Silvestro 12, 56127 Pisa, Italy
| | - D. Ercolani
- NEST–Istituto Nanoscienze–CNR and Scuola Normale Superiore, Piazza S. Silvestro 12, 56127 Pisa, Italy
| | - L. Sorba
- NEST–Istituto Nanoscienze–CNR and Scuola Normale Superiore, Piazza S. Silvestro 12, 56127 Pisa, Italy
| | - R. Aguado
- Materials Science Factory, Instituto de Ciencia de Materiales de Madrid (ICMM), Consejo Superior de Investigaciones Científicas (CSIC), Sor Juana Inés de la Cruz 3, 28049 Madrid, Spain
| | - S. De Franceschi
- Université Grenoble Alpes, CEA, INAC-PHELIQS, 38000 Grenoble, France
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