1
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Sestoft JE, Marnauza M, Olsteins D, Kanne T, Schlosser RD, Chen IJ, Grove-Rasmussen K, Nygård J. Shadowed versus Etched Superconductor-Semiconductor Junctions in Al/InAs Nanowires. NANO LETTERS 2024; 24:8394-8401. [PMID: 38865258 PMCID: PMC11249013 DOI: 10.1021/acs.nanolett.4c02055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2024]
Abstract
Hybrid semiconductor-superconductor nanowires have emerged as a cornerstone in modern quantum devices. Integrating such nanowires into hybrid devices typically requires extensive postgrowth processing which may affect device performance unfavorably. Here, we present a technique for in situ shadowing superconductors on nanowires and compare the structural and electronic properties of Al junctions formed by shadowing versus etching. Based on transmission electron microscopy, we find that typical etching procedures lead to atomic-scale surface roughening. This surface perturbation may cause a reduction of the electron mobility as demonstrated in transport measurements. Further, we display advanced shadowing geometries aiding in the pursuit of bringing fabrication of hybrid devices in situ. Finally, we give examples of shadowed junctions exploited in various device geometries that exhibit high-quality quantum transport signatures.
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Affiliation(s)
- Joachim E Sestoft
- Center for Quantum Devices and Nano-science Center, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Mikelis Marnauza
- Center for Quantum Devices and Nano-science Center, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Dags Olsteins
- Center for Quantum Devices and Nano-science Center, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Thomas Kanne
- Center for Quantum Devices and Nano-science Center, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Rasmus D Schlosser
- Center for Quantum Devices and Nano-science Center, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
| | - I-Ju Chen
- Center for Quantum Devices and Nano-science Center, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Kasper Grove-Rasmussen
- Center for Quantum Devices and Nano-science Center, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Jesper Nygård
- Center for Quantum Devices and Nano-science Center, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
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2
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Galaktionov AV, Zaikin AD. Josephson dynamics and Shapiro steps at high transmissions: current bias regime. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2024; 15:51-56. [PMID: 38229678 PMCID: PMC10790642 DOI: 10.3762/bjnano.15.5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Accepted: 12/15/2023] [Indexed: 01/18/2024]
Abstract
We investigate Josephson dynamics of highly transparent superconducting nanojunctions at subgap voltages and temperatures. In this limit, intrinsic dissipation in such junctions turns out to be sub-Ohmic, which yields a linear dependence of the average voltage on the bias current I slightly exceeding the critical one Ic. We demonstrate a strong impact of intrinsic sub-Ohmic dissipation on integer Shapiro steps appearing on the I-V curve in the presence of external microwave radiation.
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Affiliation(s)
- Artem V Galaktionov
- I.E. Tamm Department of Theoretical Physics, P.N. Lebedev Physical Institute, 119991 Moscow, Russia
| | - Andrei D Zaikin
- I.E. Tamm Department of Theoretical Physics, P.N. Lebedev Physical Institute, 119991 Moscow, Russia
- National Research University Higher School of Economics, 101000 Moscow, Russia
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3
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Valentini M, Sagi O, Baghumyan L, de Gijsel T, Jung J, Calcaterra S, Ballabio A, Aguilera Servin J, Aggarwal K, Janik M, Adletzberger T, Seoane Souto R, Leijnse M, Danon J, Schrade C, Bakkers E, Chrastina D, Isella G, Katsaros G. Parity-conserving Cooper-pair transport and ideal superconducting diode in planar germanium. Nat Commun 2024; 15:169. [PMID: 38167818 PMCID: PMC10762135 DOI: 10.1038/s41467-023-44114-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Accepted: 11/30/2023] [Indexed: 01/05/2024] Open
Abstract
Superconductor/semiconductor hybrid devices have attracted increasing interest in the past years. Superconducting electronics aims to complement semiconductor technology, while hybrid architectures are at the forefront of new ideas such as topological superconductivity and protected qubits. In this work, we engineer the induced superconductivity in two-dimensional germanium hole gas by varying the distance between the quantum well and the aluminum. We demonstrate a hard superconducting gap and realize an electrically and flux tunable superconducting diode using a superconducting quantum interference device (SQUID). This allows to tune the current phase relation (CPR), to a regime where single Cooper pair tunneling is suppressed, creating a [Formula: see text] CPR. Shapiro experiments complement this interpretation and the microwave drive allows to create a diode with ≈ 100% efficiency. The reported results open up the path towards integration of spin qubit devices, microwave resonators and (protected) superconducting qubits on the same silicon technology compatible platform.
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Affiliation(s)
- Marco Valentini
- Institute of Science and Technology Austria, Klosterneuburg, Austria.
| | - Oliver Sagi
- Institute of Science and Technology Austria, Klosterneuburg, Austria
| | - Levon Baghumyan
- Institute of Science and Technology Austria, Klosterneuburg, Austria
| | - Thijs de Gijsel
- Institute of Science and Technology Austria, Klosterneuburg, Austria
- Department of Applied Physics, Eindhoven University of Technology, Eindhoven, The Netherlands
| | - Jason Jung
- Department of Applied Physics, Eindhoven University of Technology, Eindhoven, The Netherlands
| | | | - Andrea Ballabio
- L-NESS, Physics Department, Politecnico di Milano, Como, Italy
| | | | - Kushagra Aggarwal
- Institute of Science and Technology Austria, Klosterneuburg, Austria
- Department of Materials, University of Oxford, Oxford, UK
| | - Marian Janik
- Institute of Science and Technology Austria, Klosterneuburg, Austria
| | | | - Rubén Seoane Souto
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
- Instituto de Ciencia de Materiales de Madrid, Consejo Superior de Investigaciones Científicas (ICMM-CSIC), Madrid, Spain
| | - Martin Leijnse
- NanoLund and Solid State Physics, Lund University, Lund, Sweden
| | - Jeroen Danon
- Department of Physics, Norwegian University of Science and Technology, Trondheim, Norway
| | - Constantin Schrade
- Hearne Institute for Theoretical Physics, Department of Physics and Astronomy, Louisiana State University, Baton Rouge, USA
| | - Erik Bakkers
- Department of Applied Physics, Eindhoven University of Technology, Eindhoven, The Netherlands
| | | | - Giovanni Isella
- L-NESS, Physics Department, Politecnico di Milano, Como, Italy
| | - Georgios Katsaros
- Institute of Science and Technology Austria, Klosterneuburg, Austria.
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4
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Lahiri A, Choi SJ, Trauzettel B. Nonequilibrium Fractional Josephson Effect. PHYSICAL REVIEW LETTERS 2023; 131:126301. [PMID: 37802950 DOI: 10.1103/physrevlett.131.126301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Accepted: 08/17/2023] [Indexed: 10/08/2023]
Abstract
Josephson tunnel junctions exhibit a supercurrent typically proportional to the sine of the superconducting phase difference ϕ. In general, a term proportional to cos(ϕ) is also present, alongside microscopic electronic retardation effects. We show that voltage pulses sharply varying in time prompt a significant impact of the cos(ϕ) term. Its interplay with the sin(ϕ) term results in a nonequilibrium fractional Josephson effect (NFJE) ∼sin(ϕ/2) in the presence of bound states close to zero frequency. Our microscopic analysis reveals that the interference of nonequilibrium virtual quasiparticle excitations is responsible for this phenomenon. We also analyze this phenomenon for topological Josephson junctions with Majorana bound states. Remarkably, the NFJE is independent of the ground state fermion parity unlike its equilibrium counterpart.
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Affiliation(s)
- Aritra Lahiri
- Institute for Theoretical Physics and Astrophysics, University of Würzburg, D-97074 Würzburg, Germany
| | - Sang-Jun Choi
- Institute for Theoretical Physics and Astrophysics, University of Würzburg, D-97074 Würzburg, Germany
| | - Björn Trauzettel
- Institute for Theoretical Physics and Astrophysics, University of Würzburg, D-97074 Würzburg, Germany
- Würzburg-Dresden Cluster of Excellence ct.qmat, Germany
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5
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Wang H, Zhu Y, Bai Z, Wang Z, Hu S, Xie HY, Hu X, Cui J, Huang M, Chen J, Ding Y, Zhao L, Li X, Zhang Q, Gu L, Zhou XJ, Zhu J, Zhang D, Xue QK. Prominent Josephson tunneling between twisted single copper oxide planes of Bi 2Sr 2-xLa xCuO 6+y. Nat Commun 2023; 14:5201. [PMID: 37626041 PMCID: PMC10457331 DOI: 10.1038/s41467-023-40525-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2022] [Accepted: 07/21/2023] [Indexed: 08/27/2023] Open
Abstract
Josephson tunneling in twisted cuprate junctions provides a litmus test for the pairing symmetry, which is fundamental for understanding the microscopic mechanism of high temperature superconductivity. This issue is rekindled by experimental advances in van der Waals stacking and the proposal of an emergent d+id-wave. So far, all experiments have been carried out on Bi2Sr2CaCu2O8+x (Bi-2212) with double CuO2 planes but show controversial results. Here, we investigate junctions made of Bi2Sr2-xLaxCuO6+y (Bi-2201) with single CuO2 planes. Our on-site cold stacking technique ensures uncompromised crystalline quality and stoichiometry at the interface. Junctions with carefully calibrated twist angles around 45° show strong Josephson tunneling and conventional temperature dependence. Furthermore, we observe standard Fraunhofer diffraction patterns and integer Fiske steps in a junction with a twist angle of 45.0±0.2°. Together, these results pose strong constraints on the d or d+id-wave pairing and suggest an indispensable isotropic pairing component.
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Affiliation(s)
- Heng Wang
- State Key Laboratory of Low Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing, 100084, China
| | - Yuying Zhu
- Beijing Academy of Quantum Information Sciences, Beijing, 100193, China.
- Hefei National Laboratory, Hefei, 230088, China.
| | - Zhonghua Bai
- State Key Laboratory of Low Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing, 100084, China
| | - Zechao Wang
- National Center for Electron Microscopy in Beijing, School of Materials Science and Engineering, Key Laboratory of Advanced Materials (MOE), The State Key Laboratory of New Ceramics and Fine Processing, Tsinghua University, Beijing, 100084, China
- Ji Hua Laboratory, Foshan, Guangdong, 528200, China
| | - Shuxu Hu
- State Key Laboratory of Low Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing, 100084, China
| | - Hong-Yi Xie
- Beijing Academy of Quantum Information Sciences, Beijing, 100193, China
| | - Xiaopeng Hu
- State Key Laboratory of Low Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing, 100084, China
| | - Jian Cui
- Beijing Academy of Quantum Information Sciences, Beijing, 100193, China
| | - Miaoling Huang
- Beijing Academy of Quantum Information Sciences, Beijing, 100193, China
| | - Jianhao Chen
- Beijing Academy of Quantum Information Sciences, Beijing, 100193, China
- International Center for Quantum Materials, School of Physics, Peking University, Beijing, 100091, China
| | - Ying Ding
- Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Lin Zhao
- Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Xinyan Li
- Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Qinghua Zhang
- Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Lin Gu
- National Center for Electron Microscopy in Beijing, School of Materials Science and Engineering, Key Laboratory of Advanced Materials (MOE), The State Key Laboratory of New Ceramics and Fine Processing, Tsinghua University, Beijing, 100084, China
- Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - X J Zhou
- Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Jing Zhu
- National Center for Electron Microscopy in Beijing, School of Materials Science and Engineering, Key Laboratory of Advanced Materials (MOE), The State Key Laboratory of New Ceramics and Fine Processing, Tsinghua University, Beijing, 100084, China
- Ji Hua Laboratory, Foshan, Guangdong, 528200, China
| | - Ding Zhang
- State Key Laboratory of Low Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing, 100084, China.
- Beijing Academy of Quantum Information Sciences, Beijing, 100193, China.
- RIKEN Center for Emergent Matter Science (CEMS), Wako, Saitama, 351-0198, Japan.
| | - Qi-Kun Xue
- State Key Laboratory of Low Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing, 100084, China.
- Beijing Academy of Quantum Information Sciences, Beijing, 100193, China.
- Southern University of Science and Technology, Shenzhen, 518055, China.
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6
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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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7
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Yan S, Su H, Pan D, Li W, Lyu Z, Chen M, Wu X, Lu L, Zhao J, Wang JY, Xu H. Supercurrent, Multiple Andreev Reflections and Shapiro Steps in InAs Nanosheet Josephson Junctions. NANO LETTERS 2023. [PMID: 37450769 DOI: 10.1021/acs.nanolett.3c01450] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/18/2023]
Abstract
We report an experimental study of proximity induced superconductivity in planar Josephson junction devices made from free-standing InAs nanosheets. The nanosheets are grown by molecular beam epitaxy, and the Josephson junction devices are fabricated by directly contacting the nanosheets with superconductor Al electrodes. The fabricated devices are explored by low-temperature carrier transport measurements. The measurements show that the devices exhibit a gate-tunable supercurrent, multiple Andreev reflections, and a good quality superconductor-semiconductor interface. The superconducting characteristics of the Josephson junctions are investigated at different magnetic fields and temperatures and are analyzed based on the Bardeen-Cooper-Schrieffer (BCS) theory. The measurements of the ac Josephson effect are also conducted under microwave radiations with different radiation powers and frequencies, and integer Shapiro steps are observed. Our work demonstrates that InAs nanosheet based hybrid devices are desired systems for investigating the forefront of physics, such as two-dimensional topological superconductivity.
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Affiliation(s)
- Shili Yan
- Beijing Academy of Quantum Information Sciences, 100193 Beijing, China
| | - Haitian Su
- Beijing Key Laboratory of Quantum Devices, Key Laboratory for the Physics and Chemistry of Nanodevices, and School of Electronics, Peking University, Beijing 100871, China
- Institute of Condensed Matter and Material Physics, School of Physics, Peking University, Beijing 100871, China
| | - Dong Pan
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, P.O. Box 912, Beijing 100083, China
| | - Weijie Li
- Beijing Key Laboratory of Quantum Devices, Key Laboratory for the Physics and Chemistry of Nanodevices, and School of Electronics, Peking University, Beijing 100871, China
- Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China
| | - Zhaozheng Lyu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences; School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China
| | - Mo Chen
- Beijing Academy of Quantum Information Sciences, 100193 Beijing, China
| | - Xingjun Wu
- Beijing Academy of Quantum Information Sciences, 100193 Beijing, China
| | - Li Lu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences; School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China
| | - Jianhua Zhao
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, P.O. Box 912, Beijing 100083, China
| | - Ji-Yin Wang
- Beijing Academy of Quantum Information Sciences, 100193 Beijing, China
| | - Hongqi Xu
- Beijing Academy of Quantum Information Sciences, 100193 Beijing, China
- Beijing Key Laboratory of Quantum Devices, Key Laboratory for the Physics and Chemistry of Nanodevices, and School of Electronics, Peking University, Beijing 100871, China
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8
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Rößler M, Fan D, Münning F, Legg HF, Bliesener A, Lippertz G, Uday A, Yazdanpanah R, Feng J, Taskin A, Ando Y. Top-Down Fabrication of Bulk-Insulating Topological Insulator Nanowires for Quantum Devices. NANO LETTERS 2023; 23:2846-2853. [PMID: 36976857 DOI: 10.1021/acs.nanolett.3c00169] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
In a nanowire (NW) of a three-dimensional topological insulator (TI), the quantum confinement of topological surface states leads to a peculiar sub-band structure that is useful for generating Majorana bound states. Top-down fabrication of TINWs from a high-quality thin film would be a scalable technology with great design flexibility, but there has been no report on top-down-fabricated TINWs where the chemical potential can be tuned to the charge neutrality point (CNP). Here we present a top-down fabrication process for bulk-insulating TINWs etched from high-quality (Bi1-xSbx)2Te3 thin films without degradation. We show that the chemical potential can be gate-tuned to the CNP, and the resistance of the NW presents characteristic oscillations as functions of the gate voltage and the parallel magnetic field, manifesting the TI-sub-band physics. We further demonstrate the superconducting proximity effect in these TINWs, preparing the groundwork for future devices to investigate Majorana bound states.
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Affiliation(s)
- Matthias Rößler
- University of Cologne, Physics Institute II, Zülpicher Str. 77, 50937 Köln, Germany
| | - Dingxun Fan
- University of Cologne, Physics Institute II, Zülpicher Str. 77, 50937 Köln, Germany
| | - Felix Münning
- University of Cologne, Physics Institute II, Zülpicher Str. 77, 50937 Köln, Germany
| | - Henry F Legg
- Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056 Basel, Switzerland
| | - Andrea Bliesener
- University of Cologne, Physics Institute II, Zülpicher Str. 77, 50937 Köln, Germany
| | - Gertjan Lippertz
- University of Cologne, Physics Institute II, Zülpicher Str. 77, 50937 Köln, Germany
- KU Leuven, Quantum Solid State Physics, Celestijnenlaan 200 D, 3001 Leuven, Belgium
| | - Anjana Uday
- University of Cologne, Physics Institute II, Zülpicher Str. 77, 50937 Köln, Germany
| | - Roozbeh Yazdanpanah
- University of Cologne, Physics Institute II, Zülpicher Str. 77, 50937 Köln, Germany
| | - Junya Feng
- University of Cologne, Physics Institute II, Zülpicher Str. 77, 50937 Köln, Germany
| | - Alexey Taskin
- University of Cologne, Physics Institute II, Zülpicher Str. 77, 50937 Köln, Germany
| | - Yoichi Ando
- University of Cologne, Physics Institute II, Zülpicher Str. 77, 50937 Köln, Germany
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9
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Elfeky B, Cuozzo JJ, Lotfizadeh N, Schiela WF, Farzaneh SM, Strickland WM, Langone D, Rossi E, Shabani J. Evolution of 4π-Periodic Supercurrent in the Presence of an In-Plane Magnetic Field. ACS NANO 2023; 17:4650-4658. [PMID: 36800544 PMCID: PMC10018771 DOI: 10.1021/acsnano.2c10880] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Accepted: 02/15/2023] [Indexed: 06/18/2023]
Abstract
In the presence of a 4π-periodic contribution to the current phase relation, for example in topological Josephson junctions, odd Shapiro steps are expected to be missing. While missing odd Shapiro steps have been observed in several material systems and interpreted in the context of topological superconductivity, they have also been observed in topologically trivial junctions. Here, we study the evolution of such trivial missing odd Shapiro steps in Al-InAs junctions in the presence of an in-plane magnetic field Bθ. We find that the odd steps reappear at a crossover Bθ value, exhibiting an in-plane field angle anisotropy that depends on spin-orbit coupling effects. We interpret this behavior by theoretically analyzing the Andreev bound state spectrum and the transitions induced by the nonadiabatic dynamics of the junction and attribute the observed anisotropy to mode-to-mode coupling. Our results highlight the complex phenomenology of missing Shapiro steps and the underlying current phase relations in planar Josephson junctions designed to realize Majorana states.
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Affiliation(s)
- Bassel
Heiba Elfeky
- Center
for Quantum Information Physics, Department of Physics, New York University, New York, New York 10003, United States
| | - Joseph J. Cuozzo
- Department
of Physics, William & Mary, Williamsburg, Virginia 23187, United States
| | - Neda Lotfizadeh
- Center
for Quantum Information Physics, Department of Physics, New York University, New York, New York 10003, United States
| | - William F. Schiela
- Center
for Quantum Information Physics, Department of Physics, New York University, New York, New York 10003, United States
| | - Seyed M. Farzaneh
- Center
for Quantum Information Physics, Department of Physics, New York University, New York, New York 10003, United States
| | - William M. Strickland
- Center
for Quantum Information Physics, Department of Physics, New York University, New York, New York 10003, United States
| | - Dylan Langone
- Center
for Quantum Information Physics, Department of Physics, New York University, New York, New York 10003, United States
| | - Enrico Rossi
- Department
of Physics, William & Mary, Williamsburg, Virginia 23187, United States
| | - Javad Shabani
- Center
for Quantum Information Physics, Department of Physics, New York University, New York, New York 10003, United States
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10
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Hatefipour M, Cuozzo JJ, Kanter J, Strickland WM, Allemang CR, Lu TM, Rossi E, Shabani J. Induced Superconducting Pairing in Integer Quantum Hall Edge States. NANO LETTERS 2022; 22:6173-6178. [PMID: 35867620 DOI: 10.1021/acs.nanolett.2c01413] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Indium arsenide (InAs) near surface quantum wells (QWs) are promising for the fabrication of semiconductor-superconductor heterostructures given that they allow for a strong hybridization between the two-dimensional states in the quantum well and the ones in the superconductor. In this work, we present results for InAs QWs in the quantum Hall regime placed in proximity of superconducting NbTiN. We observe a negative downstream resistance with a corresponding reduction of Hall (upstream) resistance, consistent with a very high Andreev conversion. We analyze the experimental data using the Landauer-Büttiker formalism, generalized to allow for Andreev reflection processes. We attribute the high efficiency of Andreev conversion in our devices to the large transparency of the InAs/NbTiN interface and the consequent strong hybridization of the QH edge modes with the states in the superconductor.
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Affiliation(s)
- Mehdi Hatefipour
- Center for Quantum Phenomena, Department of Physics, New York University, New York, New York 10003, United States
| | - Joseph J Cuozzo
- Department of Physics, William & Mary, Williamsburg, Virginia 23187, United States
| | - Jesse Kanter
- Center for Quantum Phenomena, Department of Physics, New York University, New York, New York 10003, United States
| | - William M Strickland
- Center for Quantum Phenomena, Department of Physics, New York University, New York, New York 10003, United States
| | | | - Tzu-Ming Lu
- Sandia National Laboratories, Albuquerque, New Mexico 87185, United States
- Center for Integrated Nanotechnologies, Sandia National Laboratories, Albuquerque, New Mexico 87123, United States
| | - Enrico Rossi
- Department of Physics, William & Mary, Williamsburg, Virginia 23187, United States
| | - Javad Shabani
- Center for Quantum Phenomena, Department of Physics, New York University, New York, New York 10003, United States
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11
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Sato Y, Ueda K, Takeshige Y, Kamata H, Li K, Samuelson L, Xu HQ, Matsuo S, Tarucha S. Quasiparticle Trapping at Vortices Producing Josephson Supercurrent Enhancement. PHYSICAL REVIEW LETTERS 2022; 128:207001. [PMID: 35657870 DOI: 10.1103/physrevlett.128.207001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Accepted: 04/04/2022] [Indexed: 06/15/2023]
Abstract
The Josephson junction of a strong spin-orbit material under a magnetic field is a promising Majorana fermion candidate. Supercurrent enhancement by a magnetic field has been observed in the InAs nanowire Josephson junctions and assigned to a topological transition. In this work we observe a similar phenomenon but discuss the nontopological origin by considering the trapping of quasiparticles by vortices that penetrate the superconductor under a finite magnetic field. This assignment is supported by the observed hysteresis of the switching current when sweeping up and down the magnetic field. Our experiment shows the importance of quasiparticles in superconducting devices with a magnetic field, which can provide important insights for the design of qubits using superconductors.
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Affiliation(s)
- Yosuke Sato
- Department of Applied Physics, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
- Center for Emergent Matter Science, RIKEN, 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan
| | - Kento Ueda
- Department of Applied Physics, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Yuusuke Takeshige
- Department of Applied Physics, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Hiroshi Kamata
- Laboratoire de Physique de l'École Normale Supérieure, ENS, PSL Research University, CNRS, Sorbonne Université, Université Paris Diderot, Sorbonne Paris Cité, 24 rue Lhomond, 75231 Paris Cedex 05, France
| | - Kan Li
- Beijing Key Laboratory of Quantum Devices, Key Laboratory for the Physics and Chemistry of Nanodevices and School of Electronics, Peking University, Beijing 100871, China
| | - Lars Samuelson
- Division of Solid State Physics and NanoLund, Lund University, Box 118, SE-221 00 Lund, Sweden
- Department of Electrical and Electronic Engineering, Southern University of Science and Technology, 1088 Xueyuan Blvd, Nanshan, Shenzhen, Guangdong 518055, China
| | - H Q Xu
- Beijing Key Laboratory of Quantum Devices, Key Laboratory for the Physics and Chemistry of Nanodevices and School of Electronics, Peking University, Beijing 100871, China
- Division of Solid State Physics and NanoLund, Lund University, Box 118, SE-221 00 Lund, Sweden
- Beijing Academy of Quantum Information Sciences, Beijing 100193, China
| | - Sadashige Matsuo
- Center for Emergent Matter Science, RIKEN, 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan
- JST, PRESTO, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan
| | - Seigo Tarucha
- Center for Emergent Matter Science, RIKEN, 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan
- RIKEN Center for Quantum Computing, RIKEN, 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan
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12
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Elfeky BH, Lotfizadeh N, Schiela WF, Strickland WM, Dartiailh M, Sardashti K, Hatefipour M, Yu P, Pankratova N, Lee H, Manucharyan VE, Shabani J. Local Control of Supercurrent Density in Epitaxial Planar Josephson Junctions. NANO LETTERS 2021; 21:8274-8280. [PMID: 34570504 DOI: 10.1021/acs.nanolett.1c02771] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The critical current response to an applied out-of-plane magnetic field in a Josephson junction provides insight into the uniformity of its current distribution. In Josephson junctions with semiconducting weak links, the carrier density, and therefore the overall current distribution, can be modified electrostatically via metallic gates. Here, we show local control of the current distribution in an epitaxial Al-InAs Josephson junction equipped with five minigates. We demonstrate that not only can the junction width be electrostatically defined but also the current profile can be locally adjusted to form superconducting quantum interference devices. Our studies show enhanced edge conduction in such long junctions, which can be eliminated by minigates to create a uniform current distribution.
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Affiliation(s)
- Bassel Heiba Elfeky
- Department of Physics, New York University, New York, New York 10003, United States
| | - Neda Lotfizadeh
- Department of Physics, New York University, New York, New York 10003, United States
| | - William F Schiela
- Department of Physics, New York University, New York, New York 10003, United States
| | - William M Strickland
- Department of Physics, New York University, New York, New York 10003, United States
| | - Matthieu Dartiailh
- Department of Physics, New York University, New York, New York 10003, United States
| | - Kasra Sardashti
- Department of Physics, New York University, New York, New York 10003, United States
| | - Mehdi Hatefipour
- Department of Physics, New York University, New York, New York 10003, United States
| | - Peng Yu
- Department of Physics, New York University, New York, New York 10003, United States
| | - Natalia Pankratova
- Department of Physics, Joint Quantum Institute, and Quantum Materials Center, University of Maryland, College Park, Maryland 20742, United States
| | - Hanho Lee
- Department of Physics, Joint Quantum Institute, and Quantum Materials Center, University of Maryland, College Park, Maryland 20742, United States
| | - Vladimir E Manucharyan
- Department of Physics, Joint Quantum Institute, and Quantum Materials Center, University of Maryland, College Park, Maryland 20742, United States
| | - Javad Shabani
- Department of Physics, New York University, New York, New York 10003, United States
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