51
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Wind L, Sistani M, Song Z, Maeder X, Pohl D, Michler J, Rellinghaus B, Weber WM, Lugstein A. Monolithic Metal-Semiconductor-Metal Heterostructures Enabling Next-Generation Germanium Nanodevices. ACS APPLIED MATERIALS & INTERFACES 2021; 13:12393-12399. [PMID: 33683092 PMCID: PMC7975277 DOI: 10.1021/acsami.1c00502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/09/2021] [Accepted: 02/23/2021] [Indexed: 06/12/2023]
Abstract
Low-dimensional Ge is perceived as a promising building block for emerging optoelectronic devices. Here, we present a wafer-scale platform technology enabling monolithic Al-Ge-Al nanostructures fabricated by a thermally induced Al-Ge exchange reaction. Transmission electron microscopy confirmed the purity and crystallinity of the formed Al segments with an abrupt interface to the remaining Ge segment. In good agreement with the theoretical value of bulk Al-Ge Schottky junctions, a barrier height of 200 ± 20 meV was determined. Photoluminescence and μ-Raman measurements proved the optical quality of the Ge channel embedded in the monolithic Al-Ge-Al heterostructure. Together with the wafer-scale accessibility, the proposed fabrication scheme may give rise to the development of key components of a broad spectrum of emerging Ge-based devices requiring monolithic metal-semiconductor-metal heterostructures with high-quality interfaces.
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Affiliation(s)
- Lukas Wind
- Institute
of Solid State Electronics, Technische Universität
Wien, Gußhausstraße 25-25a, Vienna 1040, Austria
| | - Masiar Sistani
- Institute
of Solid State Electronics, Technische Universität
Wien, Gußhausstraße 25-25a, Vienna 1040, Austria
| | - Zehao Song
- Institute
of Solid State Electronics, Technische Universität
Wien, Gußhausstraße 25-25a, Vienna 1040, Austria
| | - Xavier Maeder
- Swiss
Federal Laboratories for Materials Science and Technology, Laboratory for Mechanics of Materials and Nanostructures, Feuerwerkerstrasse 39, Thun 3602, Switzerland
| | - Darius Pohl
- Dresden
Center for Nanoanalysis, Technische Universität
Dresden, Helmholtzstraße
18, Dresden 01069, Germany
| | - Johann Michler
- Swiss
Federal Laboratories for Materials Science and Technology, Laboratory for Mechanics of Materials and Nanostructures, Feuerwerkerstrasse 39, Thun 3602, Switzerland
| | - Bernd Rellinghaus
- Dresden
Center for Nanoanalysis, Technische Universität
Dresden, Helmholtzstraße
18, Dresden 01069, Germany
| | - Walter M. Weber
- Institute
of Solid State Electronics, Technische Universität
Wien, Gußhausstraße 25-25a, Vienna 1040, Austria
| | - Alois Lugstein
- Institute
of Solid State Electronics, Technische Universität
Wien, Gußhausstraße 25-25a, Vienna 1040, Austria
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52
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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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53
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Sung Y, Vepsäläinen A, Braumüller J, Yan F, Wang JIJ, Kjaergaard M, Winik R, Krantz P, Bengtsson A, Melville AJ, Niedzielski BM, Schwartz ME, Kim DK, Yoder JL, Orlando TP, Gustavsson S, Oliver WD. Multi-level quantum noise spectroscopy. Nat Commun 2021; 12:967. [PMID: 33574240 PMCID: PMC7878521 DOI: 10.1038/s41467-021-21098-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Accepted: 01/13/2021] [Indexed: 11/08/2022] Open
Abstract
System noise identification is crucial to the engineering of robust quantum systems. Although existing quantum noise spectroscopy (QNS) protocols measure an aggregate amount of noise affecting a quantum system, they generally cannot distinguish between the underlying processes that contribute to it. Here, we propose and experimentally validate a spin-locking-based QNS protocol that exploits the multi-level energy structure of a superconducting qubit to achieve two notable advances. First, our protocol extends the spectral range of weakly anharmonic qubit spectrometers beyond the present limitations set by their lack of strong anharmonicity. Second, the additional information gained from probing the higher-excited levels enables us to identify and distinguish contributions from different underlying noise mechanisms.
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Affiliation(s)
- Youngkyu Sung
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, USA.
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, USA.
| | - Antti Vepsäläinen
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Jochen Braumüller
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Fei Yan
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, USA
- Shenzhen Institute for Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen, Guangdong, China
| | - Joel I-Jan Wang
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Morten Kjaergaard
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, USA
- Niels Bohr Institute, University of Copenhagen, 2100, Copenhagen, Denmark
| | - Roni Winik
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Philip Krantz
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Andreas Bengtsson
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | | | | | | | | | | | - Terry P Orlando
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, USA
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Simon Gustavsson
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - William D Oliver
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, USA.
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, USA.
- MIT Lincoln Laboratory, Lexington, MA, USA.
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA, USA.
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54
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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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55
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Khan SA, Lampadaris C, Cui A, Stampfer L, Liu Y, Pauka SJ, Cachaza ME, Fiordaliso EM, Kang JH, Korneychuk S, Mutas T, Sestoft JE, Krizek F, Tanta R, Cassidy MC, Jespersen TS, Krogstrup P. Highly Transparent Gatable Superconducting Shadow Junctions. ACS NANO 2020; 14:14605-14615. [PMID: 32396328 DOI: 10.1021/acsnano.0c02979] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Gate-tunable junctions are key elements in quantum devices based on hybrid semiconductor-superconductor materials. They serve multiple purposes ranging from tunnel spectroscopy probes to voltage-controlled qubit operations in gatemon and topological qubits. Common to all is that junction transparency plays a critical role. In this study, we grow single-crystalline InAs, InSb, and InAs1-xSbx semiconductor nanowires with epitaxial Al, Sn, and Pb superconductors and in situ shadowed junctions in a single-step molecular beam epitaxy process. We investigate correlations between fabrication parameters, junction morphologies, and electronic transport properties of the junctions and show that the examined in situ shadowed junctions are of significantly higher quality than the etched junctions. By varying the edge sharpness of the shadow junctions, we show that the sharpest edges yield the highest junction transparency for all three examined semiconductors. Further, critical supercurrent measurements reveal an extraordinarily high ICRN, close to the KO-2 limit. This study demonstrates a promising engineering path toward reliable gate-tunable superconducting qubits.
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Affiliation(s)
- Sabbir A Khan
- Microsoft Quantum Materials Lab Copenhagen, 2800 Lyngby, Denmark
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Charalampos Lampadaris
- Microsoft Quantum Materials Lab Copenhagen, 2800 Lyngby, Denmark
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Ajuan Cui
- Microsoft Quantum Materials Lab Copenhagen, 2800 Lyngby, Denmark
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Lukas Stampfer
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Yu Liu
- Microsoft Quantum Materials Lab Copenhagen, 2800 Lyngby, Denmark
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Sebastian J Pauka
- Microsoft Quantum Sydney, The University of Sydney, Sydney, NSW 2006, Australia
| | - Martin E Cachaza
- Microsoft Quantum Materials Lab Copenhagen, 2800 Lyngby, Denmark
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
| | | | - Jung-Hyun Kang
- Microsoft Quantum Materials Lab Copenhagen, 2800 Lyngby, Denmark
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Svetlana Korneychuk
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, 2600 GA Delft, The Netherlands
| | - Timo Mutas
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Joachim E Sestoft
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Filip Krizek
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Rawa Tanta
- Microsoft Quantum Materials Lab Copenhagen, 2800 Lyngby, Denmark
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Maja C Cassidy
- Microsoft Quantum Sydney, The University of Sydney, Sydney, NSW 2006, Australia
| | - Thomas S Jespersen
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Peter Krogstrup
- Microsoft Quantum Materials Lab Copenhagen, 2800 Lyngby, Denmark
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
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56
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Barreda JL, Hu L, Yu L, Hudis J, Keiper TD, Xia J, Wang Z, Guan J, Xiong P. Controlled Fabrication of DNA Molecular Templates for In Situ Formation and Measurement of Ultrathin Metal Nanostructures. NANO LETTERS 2020; 20:8135-8140. [PMID: 33048550 DOI: 10.1021/acs.nanolett.0c03166] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Fabrication of ultrathin metal nanostructures usually requires some combination of high-vacuum deposition and postgrowth processing, which precludes access to nanostructures of ultrasmall cross sections for most materials. DNA nanowires (NWs) are versatile insulating templates with intrinsic sub-10 nm line width. Here, we demonstrate a method of DNA template fabrication with precise control over the location and orientation of the DNA NWs. We further demonstrate that this template can be used to support formation of ultrathin metal NWs for derivative nanodevices: a metal is incrementally deposited, and electrical transport measurement is performed in situ at each step. The results show a homogeneous metal NW is obtained at a thickness as small as 0.9 nm with a cross-section of only a few nm2. The high degree of control in the location, separation, and orientation of the DNA NWs affords this method great promise in fabricating complex nanodevices based on metal NWs.
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Affiliation(s)
- Jorge L Barreda
- Department of Physics, Florida State University, Tallahassee, Florida 32306, United States
| | - Longqian Hu
- Department of Physics, Florida State University, Tallahassee, Florida 32306, United States
| | - Liuqi Yu
- Department of Physics, Florida State University, Tallahassee, Florida 32306, United States
| | - Jacob Hudis
- Department of Physics, Florida State University, Tallahassee, Florida 32306, United States
| | - Timothy D Keiper
- Department of Physics, Florida State University, Tallahassee, Florida 32306, United States
| | - Junfei Xia
- Department of Chemical and Biomedical Engineering, Florida A&M University-Florida State University College of Engineering, Florida State University, Tallahassee, Florida 32310, United States
| | - Zhibin Wang
- Department of Chemical and Biomedical Engineering, Florida A&M University-Florida State University College of Engineering, Florida State University, Tallahassee, Florida 32310, United States
| | - Jingjiao Guan
- Department of Chemical and Biomedical Engineering, Florida A&M University-Florida State University College of Engineering, Florida State University, Tallahassee, Florida 32310, United States
| | - Peng Xiong
- Department of Physics, Florida State University, Tallahassee, Florida 32306, United States
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57
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Sabonis D, Erlandsson O, Kringhøj A, van Heck B, Larsen TW, Petkovic I, Krogstrup P, Petersson KD, Marcus CM. Destructive Little-Parks Effect in a Full-Shell Nanowire-Based Transmon. PHYSICAL REVIEW LETTERS 2020; 125:156804. [PMID: 33095630 DOI: 10.1103/physrevlett.125.156804] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Accepted: 08/26/2020] [Indexed: 06/11/2023]
Abstract
A semiconductor transmon with an epitaxial Al shell fully surrounding an InAs nanowire core is investigated in the low E_{J}/E_{C} regime. Little-Parks oscillations as a function of flux along the hybrid wire axis are destructive, creating lobes of reentrant superconductivity separated by a metallic state at a half quantum of applied flux. In the first lobe, phase winding around the shell can induce topological superconductivity in the core. Coherent qubit operation is observed in both the zeroth and first lobes. Splitting of parity bands by coherent single-electron coupling across the junction is not resolved beyond line broadening, placing a bound on Majorana coupling, E_{M}/h<10 MHz, much smaller than the Josephson coupling E_{J}/h∼4.7 GHz.
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Affiliation(s)
- Deividas 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
| | - Oscar 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
| | - Anders 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
| | - Bernard van Heck
- Microsoft Quantum Lab Delft, Delft University of Technology, 2600 GA Delft, Netherlands
| | - Thorvald 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
| | - Ivana Petkovic
- 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
| | - Peter Krogstrup
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
- Microsoft Quantum Materials Lab-Copenhagen, 2800 Lyngby, Denmark
| | - Karl 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
| | - Charles 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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58
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Strambini E, Iorio A, Durante O, Citro R, Sanz-Fernández C, Guarcello C, Tokatly IV, Braggio A, Rocci M, Ligato N, Zannier V, Sorba L, Bergeret FS, Giazotto F. A Josephson phase battery. NATURE NANOTECHNOLOGY 2020; 15:656-660. [PMID: 32541945 DOI: 10.1038/s41565-020-0712-7] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Accepted: 05/12/2020] [Indexed: 06/11/2023]
Abstract
A classical battery converts chemical energy into a persistent voltage bias that can power electronic circuits. Similarly, a phase battery is a quantum device that provides a persistent phase bias to the wave function of a quantum circuit. It represents a key element for quantum technologies based on phase coherence. Here we demonstrate a phase battery in a hybrid superconducting circuit. It consists of an n-doped InAs nanowire with unpaired-spin surface states, that is proximitized by Al superconducting leads. We find that the ferromagnetic polarization of the unpaired-spin states is efficiently converted into a persistent phase bias φ0 across the wire, leading to the anomalous Josephson effect1,2. We apply an external in-plane magnetic field and, thereby, achieve continuous tuning of φ0. Hence, we can charge and discharge the quantum phase battery. The observed symmetries of the anomalous Josephson effect in the vectorial magnetic field are in agreement with our theoretical model. Our results demonstrate how the combined action of spin-orbit coupling and exchange interaction induces a strong coupling between charge, spin and superconducting phase, able to break the phase rigidity of the system.
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Affiliation(s)
- Elia Strambini
- NEST, Istituto Nanoscienze-CNR and Scuola Normale Superiore, Pisa, Italy.
| | - Andrea Iorio
- NEST, Istituto Nanoscienze-CNR and Scuola Normale Superiore, Pisa, Italy.
| | - Ofelia Durante
- Dipartimento di Fisica 'E. R. Caianiello', Università di Salerno, Fisciano, Italy
| | - Roberta Citro
- Dipartimento di Fisica 'E. R. Caianiello', Università di Salerno, Fisciano, Italy
| | | | - Claudio Guarcello
- Dipartimento di Fisica 'E. R. Caianiello', Università di Salerno, Fisciano, Italy
- Centro de Física de Materiales (CFM-MPC), Centro Mixto CSIC-UPV/EHU, San Sebastián, Spain
| | - Ilya V Tokatly
- Nano-Bio Spectroscopy Group, Departamento de Física de Materiales, Universidad del País Vasco (UPV/EHU), Donostia-San Sebastián, Spain
- Ikerbasque, Basque Foundation for Science, Bilbao, Spain
| | - Alessandro Braggio
- NEST, Istituto Nanoscienze-CNR and Scuola Normale Superiore, Pisa, Italy
| | - Mirko Rocci
- NEST, Istituto Nanoscienze-CNR and Scuola Normale Superiore, Pisa, Italy
- Francis Bitter Magnet Laboratory and Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Nadia Ligato
- NEST, Istituto Nanoscienze-CNR and Scuola Normale Superiore, Pisa, Italy
| | - Valentina Zannier
- NEST, Istituto Nanoscienze-CNR and Scuola Normale Superiore, Pisa, Italy
| | - Lucia Sorba
- NEST, Istituto Nanoscienze-CNR and Scuola Normale Superiore, Pisa, Italy
| | - F Sebastián Bergeret
- Centro de Física de Materiales (CFM-MPC), Centro Mixto CSIC-UPV/EHU, San Sebastián, Spain.
- Donostia International Physics Center (DIPC), San Sebastián, Spain.
| | - Francesco Giazotto
- NEST, Istituto Nanoscienze-CNR and Scuola Normale Superiore, Pisa, Italy.
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59
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Larsen TW, Gershenson ME, Casparis L, Kringhøj A, Pearson NJ, McNeil RPG, Kuemmeth F, Krogstrup P, Petersson KD, Marcus CM. Parity-Protected Superconductor-Semiconductor Qubit. PHYSICAL REVIEW LETTERS 2020; 125:056801. [PMID: 32794832 DOI: 10.1103/physrevlett.125.056801] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Accepted: 07/09/2020] [Indexed: 06/11/2023]
Abstract
Coherence of superconducting qubits can be improved by implementing designs that protect the parity of Cooper pairs on superconducting islands. Here, we introduce a parity-protected qubit based on voltage-controlled semiconductor nanowire Josephson junctions, taking advantage of the higher harmonic content in the energy-phase relation of few-channel junctions. A symmetric interferometer formed by two such junctions, gate-tuned into balance and frustrated by a half-quantum of applied flux, yields a cos(2φ) Josephson element, reflecting coherent transport of pairs of Cooper pairs. We demonstrate that relaxation of the qubit can be suppressed tenfold by tuning into the protected regime.
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Affiliation(s)
- T W Larsen
- Center for Quantum Devices and Microsoft Quantum Lab-Copenhagen, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
| | - M E Gershenson
- Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08854, USA
| | - L Casparis
- Center for Quantum Devices and Microsoft Quantum Lab-Copenhagen, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
| | - A Kringhøj
- Center for Quantum Devices and Microsoft Quantum Lab-Copenhagen, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
| | - N J Pearson
- Center for Quantum Devices and Microsoft Quantum Lab-Copenhagen, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
- Theoretische Physik, ETH Zurich, 8093 Zurich, Switzerland
| | - R P G McNeil
- Center for Quantum Devices and Microsoft Quantum Lab-Copenhagen, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
| | - F Kuemmeth
- Center for Quantum Devices and Microsoft Quantum Lab-Copenhagen, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
| | - P Krogstrup
- Center for Quantum Devices and Microsoft Quantum Lab-Copenhagen, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
- Microsoft Quantum Materials Lab-Copenhagen, 2800 Kongens Lyngby, Denmark
| | - K D Petersson
- Center for Quantum Devices and Microsoft Quantum Lab-Copenhagen, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
| | - 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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60
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Bargerbos A, Uilhoorn W, Yang CK, Krogstrup P, Kouwenhoven LP, de Lange G, van Heck B, Kou A. Observation of Vanishing Charge Dispersion of a Nearly Open Superconducting Island. PHYSICAL REVIEW LETTERS 2020; 124:246802. [PMID: 32639813 DOI: 10.1103/physrevlett.124.246802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Accepted: 05/15/2020] [Indexed: 06/11/2023]
Abstract
Isolation from the environment determines the extent to which charge is confined on an island, which manifests as Coulomb oscillations, such as charge dispersion. We investigate the charge dispersion of a nanowire transmon hosting a quantum dot in the junction. We observe rapid suppression of the charge dispersion with increasing junction transparency, consistent with the predicted scaling law, which incorporates two branches of the Josephson potential. We find improved qubit coherence times at the point of highest suppression, suggesting novel approaches for building charge-insensitive qubits.
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Affiliation(s)
- Arno Bargerbos
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, 2600 GA Delft, The Netherlands
| | - Willemijn Uilhoorn
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, 2600 GA Delft, The Netherlands
| | - Chung-Kai Yang
- Microsoft Quantum Lab Delft, 2600 GA Delft, The Netherlands
| | - Peter Krogstrup
- Microsoft Quantum Materials Lab and Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Kanalvej 7, 2800 Kongens Lyngby, Denmark
| | - Leo P Kouwenhoven
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, 2600 GA Delft, The Netherlands
- Microsoft Quantum Lab Delft, 2600 GA Delft, The Netherlands
| | - Gijs de Lange
- Microsoft Quantum Lab Delft, 2600 GA Delft, The Netherlands
| | | | - Angela Kou
- Microsoft Quantum Lab Delft, 2600 GA Delft, The Netherlands
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61
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Kringhøj A, van Heck B, Larsen TW, Erlandsson O, Sabonis D, Krogstrup P, Casparis L, Petersson KD, Marcus CM. Suppressed Charge Dispersion via Resonant Tunneling in a Single-Channel Transmon. PHYSICAL REVIEW LETTERS 2020; 124:246803. [PMID: 32639819 DOI: 10.1103/physrevlett.124.246803] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Accepted: 05/15/2020] [Indexed: 06/11/2023]
Abstract
We demonstrate strong suppression of charge dispersion in a semiconductor-based transmon qubit across Josephson resonances associated with a quantum dot in the junction. On resonance, dispersion is drastically reduced compared to conventional transmons with corresponding Josephson and charging energies. We develop a model of qubit dispersion for a single-channel resonance, which is in quantitative agreement with experimental data.
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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
| | - 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, The Netherlands
| | - T W Larsen
- 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
| | - D Sabonis
- Microsoft Quantum Lab Copenhagen and Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | - 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
| | - L Casparis
- Microsoft Quantum Lab Copenhagen and Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, 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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62
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Nichele F, Portolés E, Fornieri A, Whiticar AM, Drachmann ACC, Gronin S, Wang T, Gardner GC, Thomas C, Hatke AT, Manfra MJ, Marcus CM. Relating Andreev Bound States and Supercurrents in Hybrid Josephson Junctions. PHYSICAL REVIEW LETTERS 2020; 124:226801. [PMID: 32567899 DOI: 10.1103/physrevlett.124.226801] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Revised: 03/03/2020] [Accepted: 04/27/2020] [Indexed: 06/11/2023]
Abstract
We demonstrate concomitant measurement of phase-dependent critical current and Andreev bound state spectrum in a highly transmissive InAs Josephson junction embedded in a dc superconducting quantum interference device (SQUID). Tunneling spectroscopy reveals Andreev bound states with near unity transmission probability. A nonsinusoidal current-phase relation is derived from the Andreev spectrum, showing excellent agreement with the one extracted from the SQUID critical current. Both measurements are reconciled within a short junction model where multiple Andreev bound states, with various transmission probabilities, contribute to the entire supercurrent flowing in the junction.
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Affiliation(s)
- F Nichele
- Center for Quantum Devices and Microsoft Quantum Lab-Copenhagen, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
- IBM Research-Zurich, Säumerstrasse 4, 8803 Rüschlikon, Switzerland
| | - E Portolés
- Center for Quantum Devices and Microsoft Quantum Lab-Copenhagen, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | - A Fornieri
- Center for Quantum Devices and Microsoft Quantum Lab-Copenhagen, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | - A M Whiticar
- Center for Quantum Devices and Microsoft Quantum Lab-Copenhagen, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | - A C C Drachmann
- Center for Quantum Devices and Microsoft Quantum Lab-Copenhagen, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | - S Gronin
- Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907, USA
- Microsoft Quantum Purdue, Purdue University, West Lafayette, Indiana 47907, USA
| | - T Wang
- Department of Physics and Astronomy, Purdue University, West Lafayette, Indiana 47907, USA
- Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907, USA
| | - G C Gardner
- Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907, USA
- Microsoft Quantum Purdue, Purdue University, West Lafayette, Indiana 47907, USA
| | - C Thomas
- Department of Physics and Astronomy, Purdue University, West Lafayette, Indiana 47907, USA
- Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907, USA
| | - A T Hatke
- Department of Physics and Astronomy, Purdue University, West Lafayette, Indiana 47907, USA
- Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907, USA
| | - M J Manfra
- Department of Physics and Astronomy, Purdue University, West Lafayette, Indiana 47907, USA
- Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907, USA
- School of Materials Engineering, Purdue University, West Lafayette, Indiana 47907, USA
- School of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47907, USA
- Microsoft Quantum Purdue, Purdue University, West Lafayette, Indiana 47907, USA
| | - C M Marcus
- Center for Quantum Devices and Microsoft Quantum Lab-Copenhagen, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
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63
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Carrad DJ, Bjergfelt M, Kanne T, Aagesen M, Krizek F, Fiordaliso EM, Johnson E, Nygård J, Jespersen TS. Shadow Epitaxy for In Situ Growth of Generic Semiconductor/Superconductor Hybrids. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2020; 32:e1908411. [PMID: 32337791 DOI: 10.1002/adma.201908411] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Revised: 02/27/2020] [Accepted: 03/23/2020] [Indexed: 06/11/2023]
Abstract
Uniform, defect-free crystal interfaces and surfaces are crucial ingredients for realizing high-performance nanoscale devices. A pertinent example is that advances in gate-tunable and topological superconductivity using semiconductor/superconductor electronic devices are currently built on the hard proximity-induced superconducting gap obtained from epitaxial indium arsenide/aluminum heterostructures. Fabrication of devices requires selective etch processes; these exist only for InAs/Al hybrids, precluding the use of other, potentially superior material combinations. This work introduces a crystal growth platform-based on 3D structuring of growth substrates-which enables synthesis of semiconductor nanowire hybrids with in situ patterned superconductor shells. The platform eliminates the need for etching, thereby enabling full freedom in the choice of hybrid constituents. All of the most frequently used superconducting hybrid device architectures are realized and characterized. These devices exhibit increased yield and electrostatic stability compared to etched devices, and evidence of ballistic superconductivity is observed. In addition to aluminum, hybrid structures based on tantalum, niobium, and vanadium are presented.
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Affiliation(s)
- Damon J Carrad
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Copenhagen, 2100, Denmark
| | - Martin Bjergfelt
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Copenhagen, 2100, Denmark
| | - Thomas Kanne
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Copenhagen, 2100, Denmark
| | - Martin Aagesen
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Copenhagen, 2100, Denmark
- Danish Defence Research Center, Ballerup, 2750, Denmark
| | - Filip Krizek
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Copenhagen, 2100, Denmark
- Department of Spintronics, Institute of Physics, Czech Academy of Sciences, Praha 6, Prague, 162 00, Czech Republic
| | | | - Erik Johnson
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Copenhagen, 2100, Denmark
- Department of Mechanical Engineering, Technical University of Denmark, Kgs. Lyngby, 2800, Denmark
| | - Jesper Nygård
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Copenhagen, 2100, Denmark
| | - Thomas Sand Jespersen
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Copenhagen, 2100, Denmark
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64
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Stojanović VM. Bare-Excitation Ground State of a Spinless-Fermion-Boson Model and W-State Engineering in an Array of Superconducting Qubits and Resonators. PHYSICAL REVIEW LETTERS 2020; 124:190504. [PMID: 32469555 DOI: 10.1103/physrevlett.124.190504] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Accepted: 04/22/2020] [Indexed: 06/11/2023]
Abstract
This Letter unravels an interesting property of a one-dimensional lattice model that describes a single itinerant spinless fermion (excitation) coupled to zero-dimensional (dispersionless) bosons through two different nonlocal coupling mechanisms. Namely, below a critical value of the effective excitation-boson coupling strength, the exact ground state of this model is the zero-quasimomentum Bloch state of a bare (i.e., completely undressed) excitation. It is demonstrated here how this last property of the lattice model under consideration can be exploited for a fast, deterministic preparation of multipartite W states in a readily realizable system of inductively coupled superconducting qubits and microwave resonators.
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Affiliation(s)
- Vladimir M Stojanović
- Institut für Angewandte Physik, Technical University of Darmstadt, D-64289 Darmstadt, Germany
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65
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Zhang Z, Hossain ZM. Surface softening regulates size-dependent stiffness of diamond nanowires. NANOTECHNOLOGY 2020; 31:095709. [PMID: 31715594 DOI: 10.1088/1361-6528/ab56d3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Diamond nanowires (NWs) belong to an important class of nanoscale materials for their outstanding potential in mechanical, electrical, and thermal applications. However, their mechanical behavior under pristine and defective conditions remains less understood. This paper reveals a comprehensive understanding of the effective elastic behavior of diamond NWs, and it uncovers surface-softening as the dominant mechanism that regulates their effective behavior. We applied the force-based and energy-based approaches and constructed a comparative analysis to reveal the atomistic basis behind the diameter-dependent elastic properties of the nanowires. Our findings suggest the energy-based approach to produce physically meaningful results, whereas the widely used force-based scheme produces inconsistent size-dependent behavior. Results show that, with increasing diameter, the softening of the surface and the defective regimes decreases. As a direct consequence of the alteration in the softening state, the first-order elastic modulus increases with increasing diameter, whereas the second-order modulus decreases. Also, vacancy defects, even in very dilute concentrations, are found to substantially affect the elastic behavior of the nanowire. Furthermore, surface, core, and defective regimes exhibit very different roles in nanowires of different diameters: the surface regime acts as a softer regime and the core as stiffer, regardless of the diameter. Their cumulative effect is however dominated by the surface in smaller-diameter nanowire-but in wider diameter nanowires it is dominated by the core. As a result, the size-dependent behavior is strictly controlled by the softening state of the surface. The diameter-dependent elastic moduli show a power-law relation, which deviates substantially from the simple surface-to-volume ratio. These findings suggest surface-engineering as an important tool for modulating the effective behavior of brittle nanowires.
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Affiliation(s)
- Zhaocheng Zhang
- Laboratory of Mechanics & Physics of Heterogeneous Materials Department of Mechanical Engineering Center for Composite Materials University of Delaware, Newark, DE 19716, United States of America
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66
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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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67
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Sistani M, Delaforce J, Kramer RBG, Roch N, Luong MA, den Hertog MI, Robin E, Smoliner J, Yao J, Lieber CM, Naud C, Lugstein A, Buisson O. Highly Transparent Contacts to the 1D Hole Gas in Ultrascaled Ge/Si Core/Shell Nanowires. ACS NANO 2019; 13:14145-14151. [PMID: 31816231 DOI: 10.1021/acsnano.9b06809] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Semiconductor-superconductor hybrid systems have outstanding potential for emerging high-performance nanoelectronics and quantum devices. However, critical to their successful application is the fabrication of high-quality and reproducible semiconductor-superconductor interfaces. Here, we realize and measure axial Al-Ge-Al nanowire heterostructures with atomically precise interfaces, enwrapped by an ultrathin epitaxial Si layer further denoted as Al-Ge/Si-Al nanowire heterostructures. The heterostructures were synthesized by a thermally induced exchange reaction of single-crystalline Ge/Si core/shell nanowires and lithographically defined Al contact pads. Applying this heterostructure formation scheme enables self-aligned quasi one-dimensional crystalline Al leads contacting ultrascaled Ge/Si segments with contact transparencies greater than 96%. Integration into back-gated field-effect devices and continuous scaling beyond lithographic limitations allows us to exploit the full potential of the highly transparent contacts to the 1D hole gas at the Ge-Si interface. This leads to the observation of ballistic transport as well as quantum confinement effects up to temperatures of 150 K. Low-temperature measurements reveal proximity-induced superconductivity in the Ge/Si core/shell nanowires. The realization of a Josephson field-effect transistor allows us to study the subgap structure caused by multiple Andreev reflections. Most importantly, the absence of a quantum dot regime indicates a hard superconducting gap originating from the highly transparent contacts to the 1D hole gas, which is potentially interesting for the study of Majorana zero modes. Moreover, underlining the importance of the proposed thermally induced Al-Ge/Si-Al heterostructure formation technique, our system could contribute to the development of key components of quantum computing such as gatemon or transmon qubits.
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Affiliation(s)
- Masiar Sistani
- Institute of Solid State Electronics, TU Wien , Gußhausstraße 25-25a , 1040 Vienna , Austria
| | - Jovian Delaforce
- Université Grenoble Alpes, CNRS, Institut NEEL UPR2940 , F-38054 Grenoble , France
| | - Roman B G Kramer
- Université Grenoble Alpes, CNRS, Institut NEEL UPR2940 , F-38054 Grenoble , France
| | - Nicolas Roch
- Université Grenoble Alpes, CNRS, Institut NEEL UPR2940 , F-38054 Grenoble , France
| | - Minh Anh Luong
- Université Grenoble Alpes, CEA, IRIG-DEPHY , F-38054 Grenoble , France
| | - Martien I den Hertog
- Université Grenoble Alpes, CNRS, Institut NEEL UPR2940 , F-38054 Grenoble , France
| | - Eric Robin
- Université Grenoble Alpes, CEA, IRIG-DEPHY , F-38054 Grenoble , France
| | - Jürgen Smoliner
- Institute of Solid State Electronics, TU Wien , Gußhausstraße 25-25a , 1040 Vienna , Austria
| | - Jun Yao
- Department of Electrical and Computer Engineering, Institute for Applied Life Sciences , University of Massachusetts , Amherst , Massachusetts 01003 , United States
| | - Charles M Lieber
- Department of Chemistry and Chemical Biology , Harvard University , Cambridge , Massachusetts 02138 , United States
- School of Engineering and Applied Science , Harvard University , Cambridge , Massachusetts 02138 , United States
| | - Cecile Naud
- Université Grenoble Alpes, CNRS, Institut NEEL UPR2940 , F-38054 Grenoble , France
| | - Alois Lugstein
- Institute of Solid State Electronics, TU Wien , Gußhausstraße 25-25a , 1040 Vienna , Austria
| | - Olivier Buisson
- Université Grenoble Alpes, CNRS, Institut NEEL UPR2940 , F-38054 Grenoble , France
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68
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Lee KH, Chakram S, Kim SE, Mujid F, Ray A, Gao H, Park C, Zhong Y, Muller DA, Schuster DI, Park J. Two-Dimensional Material Tunnel Barrier for Josephson Junctions and Superconducting Qubits. NANO LETTERS 2019; 19:8287-8293. [PMID: 31661615 DOI: 10.1021/acs.nanolett.9b03886] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Quantum computing based on superconducting qubits requires the understanding and control of the materials, device architecture, and operation. However, the materials for the central circuit element, the Josephson junction, have mostly been focused on using the AlOx tunnel barrier. Here, we demonstrate Josephson junctions and superconducting qubits employing two-dimensional materials as the tunnel barrier. We batch-fabricate and design the critical Josephson current of these devices via layer-by-layer stacking N layers of MoS2 on the large scale. Based on such junctions, MoS2 transmon qubits are engineered and characterized in a bulk superconducting microwave resonator for the first time. Our work allows Josephson junctions to access the diverse material properties of two-dimensional materials that include a wide range of electrical and magnetic properties, which can be used to study the effects of different material properties in superconducting qubits and to engineer novel quantum circuit elements in the future.
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Affiliation(s)
- Kan-Heng Lee
- School of Applied and Engineering Physics , Cornell University , Ithaca , New York 14853 , United States
- Pritzker School of Molecular Engineering , University of Chicago , Chicago , Illinois 60637 , United States
| | - Srivatsan Chakram
- James Franck Institute , University of Chicago , Chicago , Illinois 60637 , United States
- Department of Physics , University of Chicago , Chicago , Illinois 60637 , United States
| | - Shi En Kim
- Pritzker School of Molecular Engineering , University of Chicago , Chicago , Illinois 60637 , United States
| | - Fauzia Mujid
- Department of Chemistry , University of Chicago , Chicago , Illinois 60637 , United States
| | - Ariana Ray
- School of Applied and Engineering Physics , Cornell University , Ithaca , New York 14853 , United States
| | - Hui Gao
- Department of Chemistry , University of Chicago , Chicago , Illinois 60637 , United States
- Department of Chemistry and Chemical Biology , Cornell University , Ithaca , New York 14853 , United States
| | - Chibeom Park
- James Franck Institute , University of Chicago , Chicago , Illinois 60637 , United States
- Department of Chemistry , University of Chicago , Chicago , Illinois 60637 , United States
| | - Yu Zhong
- Department of Chemistry , University of Chicago , Chicago , Illinois 60637 , United States
| | - David A Muller
- School of Applied and Engineering Physics , Cornell University , Ithaca , New York 14853 , United States
| | - David I Schuster
- Pritzker School of Molecular Engineering , University of Chicago , Chicago , Illinois 60637 , United States
- James Franck Institute , University of Chicago , Chicago , Illinois 60637 , United States
- Department of Physics , University of Chicago , Chicago , Illinois 60637 , United States
| | - Jiwoong Park
- Pritzker School of Molecular Engineering , University of Chicago , Chicago , Illinois 60637 , United States
- James Franck Institute , University of Chicago , Chicago , Illinois 60637 , United States
- Department of Chemistry , University of Chicago , Chicago , Illinois 60637 , United States
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69
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De Simoni G, Paolucci F, Puglia C, Giazotto F. Josephson Field-Effect Transistors Based on All-Metallic Al/Cu/Al Proximity Nanojunctions. ACS NANO 2019; 13:7871-7876. [PMID: 31244044 DOI: 10.1021/acsnano.9b02209] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
We demonstrate proximity-based all-metallic mesoscopic superconductor-normal metal-superconductor (SNS) field-effect controlled Josephson transistors (SNS-FETs) and show their full characterization from the critical temperature Tc down to 50 mK in the presence of both electric and magnetic fields. The ability of a static electric field-applied by means of a lateral gate electrode-to suppress the critical current Is in a proximity-induced superconductor is proven for both positive and negative gate voltage values. Is reached typically about one-third of its initial value, saturating at high gate voltages. The transconductance of our SNS-FETs obtains values as high as 100 nA/V at 100 mK. On the fundamental physics side, our results suggest that the mechanism at the basis of the observed phenomenon is quite general and does not rely on the existence of a true pairing potential, but rather the presence of superconducting correlations is enough for the effect to occur. On the technological side, our findings widen the family of materials available for the implementation of all-metallic field-effect transistors to synthetic proximity-induced superconductors.
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Affiliation(s)
- Giorgio De Simoni
- NEST Istituto Nanoscienze-CNR and Scuola Normale Superiore , I-56127 Pisa , Italy
| | - Federico Paolucci
- NEST Istituto Nanoscienze-CNR and Scuola Normale Superiore , I-56127 Pisa , Italy
- INFN Sezione di Pisa , Largo Bruno Pontecorvo 3 , 56127 Pisa , Italy
| | - Claudio Puglia
- NEST Istituto Nanoscienze-CNR and Scuola Normale Superiore , I-56127 Pisa , Italy
- Dipartimento di Fisica dell'Università di Pisa Largo Pontecorvo 3 , I-56127 Pisa , Italy
| | - Francesco Giazotto
- NEST Istituto Nanoscienze-CNR and Scuola Normale Superiore , I-56127 Pisa , Italy
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70
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Bjergfelt M, Carrad DJ, Kanne T, Aagesen M, Fiordaliso EM, Johnson E, Shojaei B, Palmstrøm CJ, Krogstrup P, Jespersen TS, Nygård J. Superconducting vanadium/indium-arsenide hybrid nanowires. NANOTECHNOLOGY 2019; 30:294005. [PMID: 30947145 DOI: 10.1088/1361-6528/ab15fc] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
We report MBE synthesis of InAs/vanadium hybrid nanowires. The vanadium was deposited without breaking ultra-high vacuum after InAs nanowire growth, minimizing any effect of oxidation and contamination at the interface between the two materials. We investigated four different substrate temperatures during vanadium deposition, ranging from -150 °C to 250 °C. The structural relation between vanadium and InAs depended on the deposition temperature. The three lower temperature depositions gave vanadium shells with a polycrystalline, granular morphology and the highest temperature resulted in vanadium reacting with the InAs nanowire. We fabricated electronic devices from the hybrid nanowires and obtained a high out-of-plane critical magnetic field, exceeding the bulk value for vanadium. However, size effects arising from the nanoscale grains resulted in the absence of a well-defined critical temperature, as well as device-to-device variation in the resistivity versus temperature dependence during the transition to the superconducting state.
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Affiliation(s)
- Martin Bjergfelt
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen, Denmark
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71
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Firestein KL, Kvashnin DG, Fernando JFS, Zhang C, Siriwardena DP, Sorokin PB, Golberg DV. Crystallography-Derived Young's Modulus and Tensile Strength of AlN Nanowires as Revealed by in Situ Transmission Electron Microscopy. NANO LETTERS 2019; 19:2084-2091. [PMID: 30786716 DOI: 10.1021/acs.nanolett.9b00263] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Aluminum nitride (AlN) has a unique combination of properties, such as high chemical and thermal stability, nontoxicity, high melting point, large energy band gap, high thermal conductivity, and intensive light emission. This combination makes AlN nanowires (NWs) a prospective material for optoelectronic and field-emission nanodevices. However, there has been very limited information on mechanical properties of AlN NWs that is essential for their reliable utilization in modern technologies. Herein, we thoroughly study mechanical properties of individual AlN NWs using direct, in situ bending and tensile tests inside a high-resolution TEM. Overall, 22 individual NWs have been tested, and a strong dependence of their Young's moduli and ultimate tensile strengths (UTS) on their growth axis crystallographic orientation is documented. The Young's modulus of NWs grown along the [101̅1] orientation is found to be in a range 160-260 GPa, whereas for those grown along the [0002] orientation it falls within a range 350-440 GPa. In situ TEM tensile tests demonstrate the UTS values up to 8.2 GPa for the [0002]-oriented NWs, which is more than 20 times larger than that of a bulk AlN compound. Such properties make AlN nanowires a highly promising material for the reinforcing applications in metal matrix and other composites. Finally, experimental results were compared and verified under a density functional theory simulation, which shows the pronounced effect of growth axis on the AlN NW mechanical behavior. The modeling reveals that with an increasing NW width the Young's modulus tends to approach the elastic constants of a bulk material.
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Affiliation(s)
- Konstantin L Firestein
- School of Chemistry, Physics and Mechanical Engineering, Science and Engineering Faculty , Queensland University of Technology (QUT) , 2nd George str. , Brisbane , Queensland 4000 , Australia
| | - Dmitry G Kvashnin
- National University of Science and Technology "MISiS" , Leninskiy Prospekt 4 , Moscow 119049 , Russian Federation
- Emanuel Institute of Biochemical Physics , Russian Academy of Sciences , Kosigina Street 4 , Moscow 119334 , Russian Federation
| | - Joseph F S Fernando
- School of Chemistry, Physics and Mechanical Engineering, Science and Engineering Faculty , Queensland University of Technology (QUT) , 2nd George str. , Brisbane , Queensland 4000 , Australia
| | - Chao Zhang
- School of Chemistry, Physics and Mechanical Engineering, Science and Engineering Faculty , Queensland University of Technology (QUT) , 2nd George str. , Brisbane , Queensland 4000 , Australia
| | - Dumindu P Siriwardena
- School of Chemistry, Physics and Mechanical Engineering, Science and Engineering Faculty , Queensland University of Technology (QUT) , 2nd George str. , Brisbane , Queensland 4000 , Australia
| | - Pavel B Sorokin
- National University of Science and Technology "MISiS" , Leninskiy Prospekt 4 , Moscow 119049 , Russian Federation
- Emanuel Institute of Biochemical Physics , Russian Academy of Sciences , Kosigina Street 4 , Moscow 119334 , Russian Federation
- Technological Institute for Superhard and Novel Carbon Materials , Centralnaya Street 7a , Troitsk 108840 , Russian Federation
| | - Dmitri V Golberg
- School of Chemistry, Physics and Mechanical Engineering, Science and Engineering Faculty , Queensland University of Technology (QUT) , 2nd George str. , Brisbane , Queensland 4000 , Australia
- International Center for Materials Nanoarchitectonics (MANA) , National Institute for Materials Science (NIMS) , Namiki 1-1 , Tsukuba , Ibaraki 3050044 , Japan
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72
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Zheng Z, Zhan H, Nie Y, Bo A, Xu X, Gu Y. General existence of flexural mode doublets in nanowires targeting vectorial sensing applications. Phys Chem Chem Phys 2019; 21:4136-4144. [PMID: 30411758 DOI: 10.1039/c8cp05408h] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Nanowires (NWs) are one of the fundamental building blocks for nanoscale devices, and have been frequently utilized as mechanical resonators. Earlier studies show that ultra-sensitive vectorial sensing toolkits can be fabricated by changing the flexural mode of NWs to oscillation doublets along two orthogonal directions. Based on in silico studies and the Timoshenko beam theory, this work finds that the dual orthogonal flexural mode of NWs can be effectively controlled through the proper selection of their growth direction. It is found that metallic NWs with a directional-independent shear modulus possess a single flexural mode. However, NWs with a directional-dependent shear modulus naturally exhibit flexural mode doublets, which do not disappear even with increasing slenderness ratio. Further studies show that such a feature generally exists in other NWs, such as Si NWs. Mimicking a pendulum configuration as used in NW-based scanning force microscopy, the cantilevered 110 Si NW demonstrates zeptogram mass resolution and a force sensitivity down to the order of 10-24 N Hz-1/2 (yN Hz-1/2) in both transverse directions. The findings in this work open up a new and facile avenue to fabricate 2D vectorial force sensors, which could enable ultra-sensitive and novel detection devices/systems for 2D effects, such as the anisotropy strength of atomic bonds.
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Affiliation(s)
- Zhuoqun Zheng
- College of Mathematics, Jilin University, 2699 Qianjin Street, Changchun, 130012, China.
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73
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Vigneau F, Mizokuchi R, Zanuz DC, Huang X, Tan S, Maurand R, Frolov S, Sammak A, Scappucci G, Lefloch F, De Franceschi S. Germanium Quantum-Well Josephson Field-Effect Transistors and Interferometers. NANO LETTERS 2019; 19:1023-1027. [PMID: 30633528 DOI: 10.1021/acs.nanolett.8b04275] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Hybrid superconductor-semiconductor structures attract increasing attention owing to a variety of potential applications in quantum computing devices. They can serve the realization of topological superconducting systems as well as gate-tunable superconducting quantum bits. Here, we combine a SiGe/Ge/SiGe quantum-well heterostructure hosting high-mobility two-dimensional holes and aluminum superconducting leads to realize prototypical hybrid devices, such as Josephson field-effect transistors (JoFETs) and superconducting quantum interference devices (SQUIDs). We observe gate-controlled supercurrent transport with Ge channels as long as one micrometer and estimate the induced superconducting gap from tunnel spectroscopy measurements. Transmission electron microscopy reveals the diffusion of Ge into the Al contacts, whereas no Al is detected in the Ge channel.
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Affiliation(s)
- Florian Vigneau
- Université Grenoble Alpes, CEA, INAC-Pheliqs , 38000 Grenoble , France
| | - Raisei Mizokuchi
- Université Grenoble Alpes, CEA, INAC-Pheliqs , 38000 Grenoble , France
| | - Dante Colao Zanuz
- Université Grenoble Alpes, CEA, INAC-Pheliqs , 38000 Grenoble , France
| | - Xuhai Huang
- Department of Physics and Astronomy , University of Pittsburgh , Pittsburgh , Pennsylvania 15260 , United States
| | - Susheng Tan
- Department of Electrical and Computer Engineering and Petersen Institute of NanoScience and Engineering , University of Pittsburgh , Pittsburgh , Pennsylvania 15260 , United States
| | - Romain Maurand
- Université Grenoble Alpes, CEA, INAC-Pheliqs , 38000 Grenoble , France
| | - Sergey Frolov
- Department of Physics and Astronomy , University of Pittsburgh , Pittsburgh , Pennsylvania 15260 , United States
| | - Amir Sammak
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology Lorentzweg 1 , 2628 CJ Delft , The Netherlands
- QuTech and TNO , Stieltjesweg 1 , 2628 CK Delft , The Netherlands
| | - Giordano Scappucci
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology Lorentzweg 1 , 2628 CJ Delft , The Netherlands
| | - Francois Lefloch
- Université Grenoble Alpes, CEA, INAC-Pheliqs , 38000 Grenoble , France
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74
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Wang JIJ, Rodan-Legrain D, Bretheau L, Campbell DL, Kannan B, Kim D, Kjaergaard M, Krantz P, Samach GO, Yan F, Yoder JL, Watanabe K, Taniguchi T, Orlando TP, Gustavsson S, Jarillo-Herrero P, Oliver WD. Coherent control of a hybrid superconducting circuit made with graphene-based van der Waals heterostructures. NATURE NANOTECHNOLOGY 2019; 14:120-125. [PMID: 30598526 DOI: 10.1038/s41565-018-0329-2] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Accepted: 11/19/2018] [Indexed: 06/09/2023]
Abstract
Quantum coherence and control is foundational to the science and engineering of quantum systems1,2. In van der Waals materials, the collective coherent behaviour of carriers has been probed successfully by transport measurements3-6. However, temporal coherence and control, as exemplified by manipulating a single quantum degree of freedom, remains to be verified. Here we demonstrate such coherence and control of a superconducting circuit incorporating graphene-based Josephson junctions. Furthermore, we show that this device can be operated as a voltage-tunable transmon qubit7-9, whose spectrum reflects the electronic properties of massless Dirac fermions travelling ballistically4,5. In addition to the potential for advancing extensible quantum computing technology, our results represent a new approach to studying van der Waals materials using microwave photons in coherent quantum circuits.
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Affiliation(s)
- Joel I-Jan Wang
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, USA.
| | - Daniel Rodan-Legrain
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Landry Bretheau
- Laboratoire des Solides Irradiés, Ecole Polytechnique, CNRS, CEA, Palaiseau, France
| | - Daniel L Campbell
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Bharath Kannan
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, USA
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - David Kim
- Massachusetts Institute of Technology (MIT) Lincoln Laboratory, Lexington, MA, USA
| | - Morten Kjaergaard
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Philip Krantz
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Gabriel O Samach
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, USA
- Massachusetts Institute of Technology (MIT) Lincoln Laboratory, Lexington, MA, USA
| | - Fei Yan
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Jonilyn L Yoder
- Massachusetts Institute of Technology (MIT) Lincoln Laboratory, Lexington, MA, USA
| | - Kenji Watanabe
- Advanced Materials Laboratory, National Institute for Materials Science, Tsukuba, Japan
| | - Takashi Taniguchi
- Advanced Materials Laboratory, National Institute for Materials Science, Tsukuba, Japan
| | - Terry P Orlando
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, USA
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Simon Gustavsson
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | | | - William D Oliver
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, USA.
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA, USA.
- Massachusetts Institute of Technology (MIT) Lincoln Laboratory, Lexington, MA, USA.
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75
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Tahan C. Graphene qubit motivates materials science. NATURE NANOTECHNOLOGY 2019; 14:102-103. [PMID: 30723330 DOI: 10.1038/s41565-019-0369-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Affiliation(s)
- Charles Tahan
- Laboratory for Physical Sciences, College Park, MD, USA.
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76
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Schrade C, Fu L. Majorana Superconducting Qubit. PHYSICAL REVIEW LETTERS 2018; 121:267002. [PMID: 30636155 DOI: 10.1103/physrevlett.121.267002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Indexed: 06/09/2023]
Abstract
We propose a platform for universal quantum computation that uses conventional s-wave superconducting leads to address a topological qubit stored in spatially separated Majorana bound states in a multiterminal topological superconductor island. Both the manipulation and readout of this "Majorana superconducting qubit" are realized by tunnel couplings between Majorana bound states and the superconducting leads. The ability of turning on and off tunnel couplings on demand by local gates enables individual qubit addressability while avoiding cross-talk errors. By combining the scalability of superconducting qubit and the robustness of topological qubits, the Majorana superconducting qubit may provide a promising and realistic route towards quantum computation.
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Affiliation(s)
- Constantin Schrade
- Department of Physics, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA
| | - Liang Fu
- Department of Physics, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA
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77
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Kroll JG, Uilhoorn W, van der Enden KL, de Jong D, Watanabe K, Taniguchi T, Goswami S, Cassidy MC, Kouwenhoven LP. Magnetic field compatible circuit quantum electrodynamics with graphene Josephson junctions. Nat Commun 2018; 9:4615. [PMID: 30397206 PMCID: PMC6218477 DOI: 10.1038/s41467-018-07124-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Accepted: 10/18/2018] [Indexed: 11/08/2022] Open
Abstract
Circuit quantum electrodynamics has proven to be a powerful tool to probe mesoscopic effects in hybrid systems and is used in several quantum computing (QC) proposals that require a transmon qubit able to operate in strong magnetic fields. To address this we integrate monolayer graphene Josephson junctions into microwave frequency superconducting circuits to create graphene based transmons. Using dispersive microwave spectroscopy we resolve graphene's characteristic band dispersion and observe coherent electronic interference effects confirming the ballistic nature of our graphene Josephson junctions. We show that the monoatomic thickness of graphene renders the device insensitive to an applied magnetic field, allowing us to perform energy level spectroscopy of the circuit in a parallel magnetic field of 1 T, an order of magnitude higher than previous studies. These results establish graphene based superconducting circuits as a promising platform for QC and the study of mesoscopic quantum effects that appear in strong magnetic fields.
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Affiliation(s)
- J G Kroll
- QuTech and Kavli Institute for Nanoscience, Delft University of Technology, 2600 GA, Delft, The Netherlands
| | - W Uilhoorn
- QuTech and Kavli Institute for Nanoscience, Delft University of Technology, 2600 GA, Delft, The Netherlands
| | - K L van der Enden
- QuTech and Kavli Institute for Nanoscience, Delft University of Technology, 2600 GA, Delft, The Netherlands
| | - D de Jong
- QuTech and Kavli Institute for Nanoscience, Delft University of Technology, 2600 GA, Delft, The Netherlands
| | - K Watanabe
- Advanced Materials Laboratory, National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044, Japan
| | - T Taniguchi
- Advanced Materials Laboratory, National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044, Japan
| | - S Goswami
- QuTech and Kavli Institute for Nanoscience, Delft University of Technology, 2600 GA, Delft, The Netherlands
| | - M C Cassidy
- QuTech and Kavli Institute for Nanoscience, Delft University of Technology, 2600 GA, Delft, The Netherlands
| | - L P Kouwenhoven
- QuTech and Kavli Institute for Nanoscience, Delft University of Technology, 2600 GA, Delft, The Netherlands.
- Microsoft Station Q Delft, 2600 GA, Delft, The Netherlands.
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78
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Gill ST, Damasco J, Janicek BE, Durkin MS, Humbert V, Gazibegovic S, Car D, Bakkers EPAM, Huang PY, Mason N. Selective-Area Superconductor Epitaxy to Ballistic Semiconductor Nanowires. NANO LETTERS 2018; 18:6121-6128. [PMID: 30200769 DOI: 10.1021/acs.nanolett.8b01534] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Semiconductor nanowires such as InAs and InSb are promising materials for studying Majorana zero modes and demonstrating non-Abelian particle exchange relevant for topological quantum computing. While evidence for Majorana bound states in nanowires has been shown, the majority of these experiments are marked by significant disorder. In particular, the interfacial inhomogeneity between the superconductor and nanowire is strongly believed to be the main culprit for disorder and the resulting "soft superconducting gap" ubiquitous in tunneling studies of hybrid semiconductor-superconductor systems. Additionally, a lack of ballistic transport in nanowire systems can create bound states that mimic Majorana signatures. We resolve these problems through the development of selective-area epitaxy of Al to InSb nanowires, a technique applicable to other nanowires and superconductors. Epitaxial InSb-Al devices generically possess a hard superconducting gap and demonstrate ballistic 1D superconductivity and near-perfect transmission of supercurrents in the single mode regime, requisites for engineering and controlling 1D topological superconductivity. Additionally, we demonstrate that epitaxial InSb-Al superconducting island devices, the building blocks for Majorana-based quantum computing applications, prepared using selective-area epitaxy can achieve micron-scale ballistic 1D transport. Our results pave the way for the development of networks of ballistic superconducting electronics for quantum device applications.
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Affiliation(s)
| | | | | | | | | | - Sasa Gazibegovic
- QuTech and Kavli Institute of NanoScience , Delft University of Technology , 2600 GA Delft , The Netherlands
- Department of Applied Physics , Eindhoven University of Technology , 5600 MB Eindhoven , The Netherlands
| | - Diana Car
- QuTech and Kavli Institute of NanoScience , Delft University of Technology , 2600 GA Delft , The Netherlands
- Department of Applied Physics , Eindhoven University of Technology , 5600 MB Eindhoven , The Netherlands
| | - Erik P A M Bakkers
- QuTech and Kavli Institute of NanoScience , Delft University of Technology , 2600 GA Delft , The Netherlands
- Department of Applied Physics , Eindhoven University of Technology , 5600 MB Eindhoven , The Netherlands
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79
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Schmidt FE, Jenkins MD, Watanabe K, Taniguchi T, Steele GA. A ballistic graphene superconducting microwave circuit. Nat Commun 2018; 9:4069. [PMID: 30287816 PMCID: PMC6172216 DOI: 10.1038/s41467-018-06595-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2018] [Accepted: 09/11/2018] [Indexed: 11/22/2022] Open
Abstract
Josephson junctions (JJ) are a fundamental component of microwave quantum circuits, such as tunable cavities, qubits, and parametric amplifiers. Recently developed encapsulated graphene JJs, with supercurrents extending over micron distance scales, have exciting potential applications as a new building block for quantum circuits. Despite this, the microwave performance of this technology has not been explored. Here, we demonstrate a microwave circuit based on a ballistic graphene JJ embedded in a superconducting cavity. We directly observe a gate-tunable Josephson inductance through the resonance frequency of the device and, using a detailed RF model, we extract this inductance quantitatively. We also observe the microwave losses of the device, and translate this into sub-gap resistances of the junction at μeV energy scales, not accessible in DC measurements. The microwave performance we observe here suggests that graphene Josephson junctions are a feasible platform for implementing coherent quantum circuits.
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Affiliation(s)
- Felix E Schmidt
- Kavli Institute of Nanoscience, Delft University of Technology, PO Box, 5046, 2600 GA, Delft, The Netherlands
| | - Mark D Jenkins
- Kavli Institute of Nanoscience, Delft University of Technology, PO Box, 5046, 2600 GA, Delft, The Netherlands
| | - Kenji Watanabe
- National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044, Japan
| | - Takashi Taniguchi
- National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044, Japan
| | - Gary A Steele
- Kavli Institute of Nanoscience, Delft University of Technology, PO Box, 5046, 2600 GA, Delft, The Netherlands.
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80
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Weber SJ. Gatemons get serious. NATURE NANOTECHNOLOGY 2018; 13:877-878. [PMID: 30038367 DOI: 10.1038/s41565-018-0218-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
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81
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Casparis L, Connolly MR, Kjaergaard M, Pearson NJ, Kringhøj A, Larsen TW, Kuemmeth F, Wang T, Thomas C, Gronin S, Gardner GC, Manfra MJ, Marcus CM, Petersson KD. Superconducting gatemon qubit based on a proximitized two-dimensional electron gas. NATURE NANOTECHNOLOGY 2018; 13:915-919. [PMID: 30038371 DOI: 10.1038/s41565-018-0207-y] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Accepted: 06/19/2018] [Indexed: 06/08/2023]
Abstract
The coherent tunnelling of Cooper pairs across Josephson junctions (JJs) generates a nonlinear inductance that is used extensively in quantum information processors based on superconducting circuits, from setting qubit transition frequencies1 and interqubit coupling strengths2 to the gain of parametric amplifiers3 for quantum-limited readout. The inductance is either set by tailoring the metal oxide dimensions of single JJs, or magnetically tuned by parallelizing multiple JJs in superconducting quantum interference devices with local current-biased flux lines. JJs based on superconductor-semiconductor hybrids represent a tantalizing all-electric alternative. The gatemon is a recently developed transmon variant that employs locally gated nanowire superconductor-semiconductor JJs for qubit control4,5. Here we go beyond proof-of-concept and demonstrate that semiconducting channels etched from a wafer-scale two-dimensional electron gas (2DEG) are a suitable platform for building a scalable gatemon-based quantum computer. We show that 2DEG gatemons meet the requirements6 by performing voltage-controlled single qubit rotations and two-qubit swap operations. We measure qubit coherence times up to ~2 μs, limited by dielectric loss in the 2DEG substrate.
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Affiliation(s)
- Lucas Casparis
- Center for Quantum Devices, Station Q Copenhagen, Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
| | - Malcolm R Connolly
- Center for Quantum Devices, Station Q Copenhagen, Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
| | - Morten Kjaergaard
- Center for Quantum Devices, Station Q Copenhagen, Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Natalie J Pearson
- Center for Quantum Devices, Station Q Copenhagen, Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
- Theoretische Physik, ETH Zürich, Zürich, Switzerland
| | - Anders Kringhøj
- Center for Quantum Devices, Station Q Copenhagen, Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
| | - Thorvald W Larsen
- Center for Quantum Devices, Station Q Copenhagen, Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
| | - Ferdinand Kuemmeth
- Center for Quantum Devices, Station Q Copenhagen, Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
| | - Tiantian Wang
- Department of Physics and Astronomy, Purdue University, West Lafayette, IN, USA
- Station Q Purdue, and Birck Nanotechnology Center, Purdue University, West Lafayette, IN, USA
| | - Candice Thomas
- Department of Physics and Astronomy, Purdue University, West Lafayette, IN, USA
- Station Q Purdue, and Birck Nanotechnology Center, Purdue University, West Lafayette, IN, USA
| | - Sergei Gronin
- Station Q Purdue, and Birck Nanotechnology Center, Purdue University, West Lafayette, IN, USA
| | - Geoffrey C Gardner
- Station Q Purdue, and Birck Nanotechnology Center, Purdue University, West Lafayette, IN, USA
| | - Michael J Manfra
- Department of Physics and Astronomy, Purdue University, West Lafayette, IN, USA
- Station Q Purdue, and Birck Nanotechnology Center, Purdue University, West Lafayette, IN, USA
- School of Materials Engineering, Purdue University, West Lafayette, IN, USA
- School of Electrical and Computer Engineering, Purdue University, West Lafayette, IN, USA
| | - Charles M Marcus
- Center for Quantum Devices, Station Q Copenhagen, Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
| | - Karl D Petersson
- Center for Quantum Devices, Station Q Copenhagen, Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark.
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82
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De Simoni G, Paolucci F, Solinas P, Strambini E, Giazotto F. Metallic supercurrent field-effect transistor. NATURE NANOTECHNOLOGY 2018; 13:802-805. [PMID: 29967460 DOI: 10.1038/s41565-018-0190-3] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Accepted: 06/07/2018] [Indexed: 06/08/2023]
Abstract
In their original formulation of superconductivity, the London brothers predicted1 the exponential suppression of an electrostatic field inside a superconductor over the so-called London penetration depth2-4, λL. Despite a few experiments indicating hints of perturbation induced by electrostatic fields5-7, no clue has been provided so far on the possibility to manipulate metallic superconductors via the field effect. Here, we report field-effect control of the supercurrent in all-metallic transistors made of different Bardeen-Cooper-Schrieffer superconducting thin films. At low temperature, our field-effect transistors show a monotonic decay of the critical current under increasing electrostatic field up to total quenching for gate voltage values as large as ±40 V in titanium-based devices. This bipolar field effect persists up to ~85% of the critical temperature (~0.41 K), and in the presence of sizable magnetic fields. A similar behaviour is observed in aluminium thin-film field-effect transistors. A phenomenological theory accounts for our observations, and points towards the interpretation in terms of an electric-field-induced perturbation propagating inside the superconducting film. In our understanding, this affects the pairing potential and quenches the supercurrent. These results could represent a groundbreaking asset for the realization of all-metallic superconducting field-effect electronics and leading-edge quantum information architectures8,9.
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Affiliation(s)
- Giorgio De Simoni
- NEST, Istituto Nanoscienze-CNR and Scuola Normale Superiore, Pisa, Italy
| | - Federico Paolucci
- NEST, Istituto Nanoscienze-CNR and Scuola Normale Superiore, Pisa, Italy
| | | | - Elia Strambini
- NEST, Istituto Nanoscienze-CNR and Scuola Normale Superiore, Pisa, Italy
| | - Francesco Giazotto
- NEST, Istituto Nanoscienze-CNR and Scuola Normale Superiore, Pisa, Italy.
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83
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Hays M, de Lange G, Serniak K, van Woerkom DJ, Bouman D, Krogstrup P, Nygård J, Geresdi A, Devoret MH. Direct Microwave Measurement of Andreev-Bound-State Dynamics in a Semiconductor-Nanowire Josephson Junction. PHYSICAL REVIEW LETTERS 2018; 121:047001. [PMID: 30095962 DOI: 10.1103/physrevlett.121.047001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Indexed: 06/08/2023]
Abstract
The modern understanding of the Josephson effect in mesosopic devices derives from the physics of Andreev bound states, fermionic modes that are localized in a superconducting weak link. Recently, Josephson junctions constructed using semiconducting nanowires have led to the realization of superconducting qubits with gate-tunable Josephson energies. We have used a microwave circuit QED architecture to detect Andreev bound states in such a gate-tunable junction based on an aluminum-proximitized indium arsenide nanowire. We demonstrate coherent manipulation of these bound states, and track the bound-state fermion parity in real time. Individual parity-switching events due to nonequilibrium quasiparticles are observed with a characteristic timescale T_{parity}=160±10 μs. The T_{parity} of a topological nanowire junction sets a lower bound on the bandwidth required for control of Majorana bound states.
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Affiliation(s)
- M Hays
- Department of Applied Physics, Yale University, New Haven, Connecticut 06520, USA
| | - G de Lange
- Department of Applied Physics, Yale University, New Haven, Connecticut 06520, USA
- QuTech and Delft University of Technology, 2600 GA Delft, Netherlands
- Kavli Institute of Nanoscience, Delft University of Technology, 2600 GA Delft, Netherlands
| | - K Serniak
- Department of Applied Physics, Yale University, New Haven, Connecticut 06520, USA
| | - D J van Woerkom
- QuTech and Delft University of Technology, 2600 GA Delft, Netherlands
- Kavli Institute of Nanoscience, Delft University of Technology, 2600 GA Delft, Netherlands
| | - D Bouman
- QuTech and Delft University of Technology, 2600 GA Delft, Netherlands
- Kavli Institute of Nanoscience, Delft University of Technology, 2600 GA Delft, Netherlands
| | - P Krogstrup
- 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
| | - A Geresdi
- QuTech and Delft University of Technology, 2600 GA Delft, Netherlands
- Kavli Institute of Nanoscience, Delft University of Technology, 2600 GA Delft, Netherlands
| | - M H Devoret
- Department of Applied Physics, Yale University, New Haven, Connecticut 06520, USA
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84
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Hendrickx NW, Franke DP, Sammak A, Kouwenhoven M, Sabbagh D, Yeoh L, Li R, Tagliaferri MLV, Virgilio M, Capellini G, Scappucci G, Veldhorst M. Gate-controlled quantum dots and superconductivity in planar germanium. Nat Commun 2018; 9:2835. [PMID: 30026466 PMCID: PMC6053419 DOI: 10.1038/s41467-018-05299-x] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Accepted: 06/20/2018] [Indexed: 11/09/2022] Open
Abstract
Superconductors and semiconductors are crucial platforms in the field of quantum computing. They can be combined to hybrids, bringing together physical properties that enable the discovery of new emergent phenomena and provide novel strategies for quantum control. The involved semiconductor materials, however, suffer from disorder, hyperfine interactions or lack of planar technology. Here we realise an approach that overcomes these issues altogether and integrate gate-defined quantum dots and superconductivity into germanium heterostructures. In our system, heavy holes with mobilities exceeding 500,000 cm2 (Vs)-1 are confined in shallow quantum wells that are directly contacted by annealed aluminium leads. We observe proximity-induced superconductivity in the quantum well and demonstrate electric gate-control of the supercurrent. Germanium therefore has great promise for fast and coherent quantum hardware and, being compatible with standard manufacturing, could become a leading material for quantum information processing.
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Affiliation(s)
- N W Hendrickx
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, PO Box 5046, 2600 GA, Delft, The Netherlands.
| | - D P Franke
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, PO Box 5046, 2600 GA, Delft, The Netherlands
| | - A Sammak
- QuTech and the Netherlands Organisation for Applied Scientific Research (TNO), Stieltjesweg 1, 2628 CK, Delft, The Netherlands
| | - M Kouwenhoven
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, PO Box 5046, 2600 GA, Delft, The Netherlands
| | - D Sabbagh
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, PO Box 5046, 2600 GA, Delft, The Netherlands
| | - L Yeoh
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, PO Box 5046, 2600 GA, Delft, The Netherlands
| | - R Li
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, PO Box 5046, 2600 GA, Delft, The Netherlands
| | - M L V Tagliaferri
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, PO Box 5046, 2600 GA, Delft, The Netherlands
| | - M Virgilio
- Dipartimento di Fisica "E. Fermi", Università di Pisa, Largo Pontecorvo 3, 56127, Pisa, Italy
| | - G Capellini
- Dipartimento di Scienze, Università degli studi Roma Tre, Viale Marconi 446, 00146, Roma, Italy
- IHP, Im Technologiepark 25, 15236, Frankfurt (Oder), Germany
| | - G Scappucci
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, PO Box 5046, 2600 GA, Delft, The Netherlands
| | - M Veldhorst
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, PO Box 5046, 2600 GA, Delft, The Netherlands.
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85
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Paolucci F, De Simoni G, Strambini E, Solinas P, Giazotto F. Ultra-Efficient Superconducting Dayem Bridge Field-Effect Transistor. NANO LETTERS 2018; 18:4195-4199. [PMID: 29894197 DOI: 10.1021/acs.nanolett.8b01010] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Superconducting field-effect transitor (SuFET) and Josephson field-effect transistor (JoFET) technologies take advantage of electric-field-induced control of charge-carrier concentration to modulate the channel superconducting properties. Despite the fact that the field-effect is believed to be ineffective for superconducting metals, recent experiments showed electric-field-dependent modulation of the critical current ( IC) in a fully metallic transistor. However, the grounding mechanism of this phenomenon is not completely understood. Here, we show the experimental realization of Ti-based Dayem bridge field-effect transistors (DB-FETs) able to control the IC of the superconducting channel. Our easy fabrication process for DB-FETs show symmetric full suppression of IC for applied critical gate voltages as low as VGC ≃ ±8 V at temperatures reaching about the 85% of the record critical temperature, TC ≃ 550 mK, for titanium. The gate-independent TC and normal-state resistance ( RN) coupled with the increase of resistance in the superconducting state ( RS) for gate voltages close to the critical value ( VGC) suggest the creation of field-effect induced metallic puddles in the superconducting sea. Our devices show extremely high values of transconductance (| gmMAX| ≃ 15 μA/V at VG ≃ ±6.5 V) and variations of Josephson kinetic inductance ( LK) with VG of 2 orders of magnitude. Therefore, the DB-FET appears as an ideal candidate for the realization of superconducting electronics, superconducting qubits, and tunable interferometers as well as photon detectors.
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Affiliation(s)
- Federico Paolucci
- NEST , Instituto Nanoscienze-CNR and Scuola Normale Superiore , I-56127 Pisa , Italy
| | - Giorgio De Simoni
- NEST , Instituto Nanoscienze-CNR and Scuola Normale Superiore , I-56127 Pisa , Italy
| | - Elia Strambini
- NEST , Instituto Nanoscienze-CNR and Scuola Normale Superiore , I-56127 Pisa , Italy
| | - Paolo Solinas
- SPIN-CNR , Via Dodecaneso 33 , I-16146 Genova , Italy
| | - Francesco Giazotto
- NEST , Instituto Nanoscienze-CNR and Scuola Normale Superiore , I-56127 Pisa , Italy
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86
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Stolyarov VS, Cren T, Brun C, Golovchanskiy IA, Skryabina OV, Kasatonov DI, Khapaev MM, Kupriyanov MY, Golubov AA, Roditchev D. Expansion of a superconducting vortex core into a diffusive metal. Nat Commun 2018; 9:2277. [PMID: 29891870 PMCID: PMC5995889 DOI: 10.1038/s41467-018-04582-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Accepted: 05/08/2018] [Indexed: 11/27/2022] Open
Abstract
Vortices in quantum condensates exist owing to a macroscopic phase coherence. Here we show, both experimentally and theoretically, that a quantum vortex with a well-defined core can exist in a rather thick normal metal, proximized with a superconductor. Using scanning tunneling spectroscopy we reveal a proximity vortex lattice at the surface of 50 nm-thick Cu-layer deposited on Nb. We demonstrate that these vortices have regular round cores in the centers of which the proximity minigap vanishes. The cores are found to be significantly larger than the Abrikosov vortex cores in Nb, which is related to the effective coherence length in the proximity region. We develop a theoretical approach that provides a fully self-consistent picture of the evolution of the vortex with the distance from Cu/Nb interface, the interface impedance, applied magnetic field, and temperature. Our work opens a way for the accurate tuning of the superconducting properties of quantum hybrids.
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Affiliation(s)
- Vasily S Stolyarov
- Moscow Institute of Physics and Technology, 141700, Dolgoprudny, Russia.
- Institut des Nanosciences de Paris, Sorbonne Université, CNRS, UMR7588, 75251, Paris, France.
- Institute of Solid State Physics RAS, 142432, Chernogolovka, Russia.
- Fundamental Physical and Chemical Engineering Department, MSU, 119991, Moscow, Russia.
- National University of Science and Technology MISIS, 119049, Moscow, Russia.
| | - Tristan Cren
- Institut des Nanosciences de Paris, Sorbonne Université, CNRS, UMR7588, 75251, Paris, France
| | - Christophe Brun
- Institut des Nanosciences de Paris, Sorbonne Université, CNRS, UMR7588, 75251, Paris, France
| | - Igor A Golovchanskiy
- Moscow Institute of Physics and Technology, 141700, Dolgoprudny, Russia
- National University of Science and Technology MISIS, 119049, Moscow, Russia
| | - Olga V Skryabina
- Moscow Institute of Physics and Technology, 141700, Dolgoprudny, Russia
- Institute of Solid State Physics RAS, 142432, Chernogolovka, Russia
| | | | - Mikhail M Khapaev
- Moscow Institute of Physics and Technology, 141700, Dolgoprudny, Russia
- Faculty of Computational Mathematics and Cybernetics MSU, 119991, Moscow, Russia
- Skobeltsyn Institute of Nuclear Physics, MSU, 119991, Moscow, Russia
| | - Mikhail Yu Kupriyanov
- Moscow Institute of Physics and Technology, 141700, Dolgoprudny, Russia
- Skobeltsyn Institute of Nuclear Physics, MSU, 119991, Moscow, Russia
- Solid State Physics Department, Kazan Federal University, 420008, Kazan, Russia
| | - Alexander A Golubov
- Moscow Institute of Physics and Technology, 141700, Dolgoprudny, Russia
- Faculty of Science and Technology and MESA+ Institute of Nanotechnology, 7500 AE, Enschede, The Netherlands
| | - Dimitri Roditchev
- Moscow Institute of Physics and Technology, 141700, Dolgoprudny, Russia.
- Institut des Nanosciences de Paris, Sorbonne Université, CNRS, UMR7588, 75251, Paris, France.
- LPEM, ESPCI Paris, PSL Research University, CNRS, 75005, Paris, France.
- Sorbonne Université, CNRS, LPEM, 75005, Paris, France.
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87
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O'Brien TE, Rożek P, Akhmerov AR. Majorana-Based Fermionic Quantum Computation. PHYSICAL REVIEW LETTERS 2018; 120:220504. [PMID: 29906132 DOI: 10.1103/physrevlett.120.220504] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Revised: 04/05/2018] [Indexed: 06/08/2023]
Abstract
Because Majorana zero modes store quantum information nonlocally, they are protected from noise, and have been proposed as a building block for a quantum computer. We show how to use the same protection from noise to implement universal fermionic quantum computation. Our architecture requires only two Majorana modes to encode a fermionic quantum degree of freedom, compared to alternative implementations which require a minimum of four Majorana modes for a spin quantum degree of freedom. The fermionic degrees of freedom support both unitary coupled cluster variational quantum eigensolver and quantum phase estimation algorithms, proposed for quantum chemistry simulations. Because we avoid the Jordan-Wigner transformation, our scheme has a lower overhead for implementing both of these algorithms, allowing for simulation of the Trotterized Hubbard Hamiltonian in O(1) time per unitary step. We finally demonstrate magic state distillation in our fermionic architecture, giving a universal set of topologically protected fermionic quantum gates.
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Affiliation(s)
- T E O'Brien
- Instituut-Lorentz, Universiteit Leiden, P.O. Box 9506, 2300 RA Leiden, Netherlands
| | - P Rożek
- QuTech, Delft University of Technology, P.O. Box 5046, 2600 GA Delft, Netherlands
- Kavli Institute of Nanoscience, Delft University of Technology, P.O. Box 5046, 2600 GA Delft, Netherlands
| | - A R Akhmerov
- Kavli Institute of Nanoscience, Delft University of Technology, P.O. Box 5046, 2600 GA Delft, Netherlands
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88
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Pozina G, Gubaydullin AR, Mitrofanov MI, Kaliteevski MA, Levitskii IV, Voznyuk GV, Tatarinov EE, Evtikhiev VP, Rodin SN, Kaliteevskiy VN, Chechurin LS. Approach to high quality GaN lateral nanowires and planar cavities fabricated by focused ion beam and metal-organic vapor phase epitaxy. Sci Rep 2018; 8:7218. [PMID: 29740066 PMCID: PMC5940688 DOI: 10.1038/s41598-018-25647-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Accepted: 04/25/2018] [Indexed: 12/02/2022] Open
Abstract
We have developed a method to fabricate GaN planar nanowires and cavities by combination of Focused Ion Beam (FIB) patterning of the substrate followed by Metal Organic Vapor Phase Epitaxy (MOVPE). The method includes depositing a silicon nitride mask on a sapphire substrate, etching of the trenches in the mask by FIB with a diameter of 40 nm with subsequent MOVPE growth of GaN within trenches. It was observed that the growth rate of GaN is substantially increased due to enhanced bulk diffusion of the growth precursor therefore the model for analysis of the growth rate was developed. The GaN strips fabricated by this method demonstrate effective luminescence properties. The structures demonstrate enhancement of spontaneous emission via formation of Fabry-Perot modes.
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Affiliation(s)
- Galia Pozina
- Department of Physics, Chemistry and Biology (IFM), Linköping University, S-581 83, Linköping, Sweden.
| | - Azat R Gubaydullin
- St-Petersburg Academic University Khlopina 8/3, 194021, St. Petersburg, Russian Federation.,ITMO University, Kronverkskiy pr. 49, 197101, St. Petersburg, Russian Federation
| | - Maxim I Mitrofanov
- Ioffe Institute, Politekhnicheskaya 26, 194021, St. Petersburg, Russian Federation.,SHM R&E Center RAS, 194021, St. Petersburg, Russian Federation
| | - Mikhail A Kaliteevski
- St-Petersburg Academic University Khlopina 8/3, 194021, St. Petersburg, Russian Federation.,ITMO University, Kronverkskiy pr. 49, 197101, St. Petersburg, Russian Federation.,Ioffe Institute, Politekhnicheskaya 26, 194021, St. Petersburg, Russian Federation
| | - Iaroslav V Levitskii
- Ioffe Institute, Politekhnicheskaya 26, 194021, St. Petersburg, Russian Federation.,SHM R&E Center RAS, 194021, St. Petersburg, Russian Federation
| | - Gleb V Voznyuk
- ITMO University, Kronverkskiy pr. 49, 197101, St. Petersburg, Russian Federation
| | - Evgeniy E Tatarinov
- ITMO University, Kronverkskiy pr. 49, 197101, St. Petersburg, Russian Federation
| | - Vadim P Evtikhiev
- Ioffe Institute, Politekhnicheskaya 26, 194021, St. Petersburg, Russian Federation
| | - Sergey N Rodin
- Ioffe Institute, Politekhnicheskaya 26, 194021, St. Petersburg, Russian Federation.,SHM R&E Center RAS, 194021, St. Petersburg, Russian Federation
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89
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Luthi F, Stavenga T, Enzing OW, Bruno A, Dickel C, Langford NK, Rol MA, Jespersen TS, Nygård J, Krogstrup P, DiCarlo L. Evolution of Nanowire Transmon Qubits and Their Coherence in a Magnetic Field. PHYSICAL REVIEW LETTERS 2018; 120:100502. [PMID: 29570312 DOI: 10.1103/physrevlett.120.100502] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Indexed: 06/08/2023]
Abstract
We present an experimental study of flux- and gate-tunable nanowire transmons with state-of-the-art relaxation time allowing quantitative extraction of flux and charge noise coupling to the Josephson energy. We evidence coherence sweet spots for charge, tuned by voltage on a proximal side gate, where first order sensitivity to switching two-level systems and background 1/f noise is minimized. Next, we investigate the evolution of a nanowire transmon in a parallel magnetic field up to 70 mT, the upper bound set by the closing of the induced gap. Several features observed in the field dependence of qubit energy relaxation and dephasing times are not fully understood. Using nanowires with a thinner, partially covering Al shell will enable operation of these circuits up to 0.5 T, a regime relevant for topological quantum computation and other applications.
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Affiliation(s)
- F Luthi
- QuTech, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, Netherlands
- Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, Netherlands
| | - T Stavenga
- QuTech, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, Netherlands
- Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, Netherlands
| | - O W Enzing
- QuTech, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, Netherlands
- Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, Netherlands
| | - A Bruno
- QuTech, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, Netherlands
- Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, Netherlands
| | - C Dickel
- QuTech, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, Netherlands
- Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, Netherlands
| | - N K Langford
- QuTech, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, Netherlands
- Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, Netherlands
| | - M A Rol
- QuTech, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, Netherlands
- Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, Netherlands
| | - T S Jespersen
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, DK-2100 Copenhagen, Denmark
| | - J Nygård
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, DK-2100 Copenhagen, Denmark
- Nano-Science Center, Niels Bohr Institute, University of Copenhagen, DK-2100 Copenhagen, Denmark
| | - P Krogstrup
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, DK-2100 Copenhagen, Denmark
| | - L DiCarlo
- QuTech, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, Netherlands
- Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, Netherlands
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90
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Kim J, Kim BK, Kim HS, Hwang A, Kim B, Doh YJ. Macroscopic Quantum Tunneling in Superconducting Junctions of β-Ag 2Se Topological Insulator Nanowire. NANO LETTERS 2017; 17:6997-7002. [PMID: 29064253 DOI: 10.1021/acs.nanolett.7b03571] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We report on the fabrication and electrical transport properties of superconducting junctions made of β-Ag2Se topological insulator (TI) nanowires in contact with Al superconducting electrodes. The temperature dependence of the critical current indicates that the superconducting junction belongs to a short and diffusive junction regime. As a characteristic feature of the narrow junction, the critical current decreases monotonously with increasing magnetic field. The stochastic distribution of the switching current exhibits the macroscopic quantum tunneling behavior, which is robust up to T = 0.8 K. Our observations indicate that the TI nanowire-based Josephson junctions can be a promising building block for the development of nanohybrid superconducting quantum bits.
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Affiliation(s)
- Jihwan Kim
- Department of Chemistry, KAIST , Daejeon 34141, Korea
| | - Bum-Kyu Kim
- Department of Physics and Photon Science, Gwangju Institute of Science and Technology (GIST) , Gwangju 61005, Korea
| | - Hong-Seok Kim
- Department of Physics and Photon Science, Gwangju Institute of Science and Technology (GIST) , Gwangju 61005, Korea
| | - Ahreum Hwang
- Department of Chemistry, KAIST , Daejeon 34141, Korea
| | - Bongsoo Kim
- Department of Chemistry, KAIST , Daejeon 34141, Korea
| | - Yong-Joo Doh
- Department of Physics and Photon Science, Gwangju Institute of Science and Technology (GIST) , Gwangju 61005, Korea
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91
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Zuo K, Mourik V, Szombati DB, Nijholt B, van Woerkom DJ, Geresdi A, Chen J, Ostroukh VP, Akhmerov AR, Plissard SR, Car D, Bakkers EPAM, Pikulin DI, Kouwenhoven LP, Frolov SM. Supercurrent Interference in Few-Mode Nanowire Josephson Junctions. PHYSICAL REVIEW LETTERS 2017; 119:187704. [PMID: 29219554 DOI: 10.1103/physrevlett.119.187704] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Indexed: 06/07/2023]
Abstract
Junctions created by coupling two superconductors via a semiconductor nanowire in the presence of high magnetic fields are the basis for the potential detection, fusion, and braiding of Majorana bound states. We study NbTiN/InSb nanowire/NbTiN Josephson junctions and find that the dependence of the critical current on the magnetic field exhibits gate-tunable nodes. This is in contrast with a well-known Fraunhofer effect, under which critical current nodes form a regular pattern with a period fixed by the junction area. Based on a realistic numerical model we conclude that the Zeeman effect induced by the magnetic field and the spin-orbit interaction in the nanowire are insufficient to explain the observed evolution of the Josephson effect. We find the interference between the few occupied one-dimensional modes in the nanowire to be the dominant mechanism responsible for the critical current behavior. We also report a strong suppression of critical currents at finite magnetic fields that should be taken into account when designing circuits based on Majorana bound states.
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Affiliation(s)
- Kun Zuo
- QuTech, Delft University of Technology, 2600 GA Delft, Netherlands
- Kavli Institute of Nanoscience, Delft University of Technology, 2600 GA Delft, Netherlands
| | - Vincent Mourik
- QuTech, Delft University of Technology, 2600 GA Delft, Netherlands
- Kavli Institute of Nanoscience, Delft University of Technology, 2600 GA Delft, Netherlands
- Centre for Quantum Computation and Communication Technologies, School of Electrical Engineering and Telecommunications, UNSW Sydney, Sydney, New South Wales 2052, Australia
| | - Daniel B Szombati
- QuTech, Delft University of Technology, 2600 GA Delft, Netherlands
- Kavli Institute of Nanoscience, Delft University of Technology, 2600 GA Delft, Netherlands
- Australian Research Council Centre of Excellence for Engineered Quantum Systems, St Lucia, Queensland 4072, Australia
- School of Mathematics and Physics, University of Queensland, St Lucia, Queensland 4072, Australia
| | - Bas Nijholt
- Kavli Institute of Nanoscience, Delft University of Technology, 2600 GA Delft, Netherlands
| | - David J van Woerkom
- QuTech, Delft University of Technology, 2600 GA Delft, Netherlands
- Kavli Institute of Nanoscience, Delft University of Technology, 2600 GA Delft, Netherlands
- Department of Physics, ETH Zurich, CH-8093 Zurich, Switzerland
| | - Attila Geresdi
- QuTech, Delft University of Technology, 2600 GA Delft, Netherlands
- Kavli Institute of Nanoscience, Delft University of Technology, 2600 GA Delft, Netherlands
| | - Jun Chen
- Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA
| | | | - Anton R Akhmerov
- Kavli Institute of Nanoscience, Delft University of Technology, 2600 GA Delft, Netherlands
| | - Sebastién R Plissard
- Kavli Institute of Nanoscience, Delft University of Technology, 2600 GA Delft, Netherlands
- Department of Applied Physics, Eindhoven University of Technology, 5600 MB Eindhoven, Netherlands
| | - Diana Car
- QuTech, Delft University of Technology, 2600 GA Delft, Netherlands
- Kavli Institute of Nanoscience, Delft University of Technology, 2600 GA Delft, Netherlands
- Department of Applied Physics, Eindhoven University of Technology, 5600 MB Eindhoven, Netherlands
| | - Erik P A M Bakkers
- QuTech, Delft University of Technology, 2600 GA Delft, Netherlands
- Kavli Institute of Nanoscience, Delft University of Technology, 2600 GA Delft, Netherlands
- Department of Applied Physics, Eindhoven University of Technology, 5600 MB Eindhoven, Netherlands
| | - Dmitry I Pikulin
- Station Q, Microsoft Research, Santa Barbara, California 93106-6105, USA
- Department of Physics and Astronomy, University of British Columbia, Vancouver British Columbia, Canada V6T 1Z1
- Quantum Matter Institute, University of British Columbia, Vancouver British Columbia, Canada V6T 1Z4
| | - Leo P Kouwenhoven
- QuTech, Delft University of Technology, 2600 GA Delft, Netherlands
- Kavli Institute of Nanoscience, Delft University of Technology, 2600 GA Delft, Netherlands
- Station Q Delft, Microsoft Research, 2600 GA, Delft, Netherlands
| | - Sergey M Frolov
- Kavli Institute of Nanoscience, Delft University of Technology, 2600 GA Delft, Netherlands
- Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA
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92
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Cottet A, Dartiailh MC, Desjardins MM, Cubaynes T, Contamin LC, Delbecq M, Viennot JJ, Bruhat LE, Douçot B, Kontos T. Cavity QED with hybrid nanocircuits: from atomic-like physics to condensed matter phenomena. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2017; 29:433002. [PMID: 28925381 DOI: 10.1088/1361-648x/aa7b4d] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Circuit QED techniques have been instrumental in manipulating and probing with exquisite sensitivity the quantum state of superconducting quantum bits coupled to microwave cavities. Recently, it has become possible to fabricate new devices in which the superconducting quantum bits are replaced by hybrid mesoscopic circuits combining nanoconductors and metallic reservoirs. This mesoscopic QED provides a new experimental playground to study the light-matter interaction in electronic circuits. Here, we present the experimental state of the art of mesoscopic QED and its theoretical description. A first class of experiments focuses on the artificial atom limit, where some quasiparticles are trapped in nanocircuit bound states. In this limit, the circuit QED techniques can be used to manipulate and probe electronic degrees of freedom such as confined charges, spins, or Andreev pairs. A second class of experiments uses cavity photons to reveal the dynamics of electron tunneling between a nanoconductor and fermionic reservoirs. For instance, the Kondo effect, the charge relaxation caused by grounded metallic contacts, and the photo-emission caused by voltage-biased reservoirs have been studied. The tunnel coupling between nanoconductors and fermionic reservoirs also enable one to obtain split Cooper pairs, or Majorana bound states. Cavity photons represent a qualitatively new tool to study these exotic condensed matter states.
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Affiliation(s)
- Audrey Cottet
- Laboratoire Pierre Aigrain, Ecole Normale Supérieure, CNRS UMR 8551, Laboratoire associé aux universités Pierre et Marie Curie et Denis Diderot, 24, rue Lhomond, 75231 Paris Cedex 05, France
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93
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Wendin G. Quantum information processing with superconducting circuits: a review. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2017; 80:106001. [PMID: 28682303 DOI: 10.1088/1361-6633/aa7e1a] [Citation(s) in RCA: 107] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
During the last ten years, superconducting circuits have passed from being interesting physical devices to becoming contenders for near-future useful and scalable quantum information processing (QIP). Advanced quantum simulation experiments have been shown with up to nine qubits, while a demonstration of quantum supremacy with fifty qubits is anticipated in just a few years. Quantum supremacy means that the quantum system can no longer be simulated by the most powerful classical supercomputers. Integrated classical-quantum computing systems are already emerging that can be used for software development and experimentation, even via web interfaces. Therefore, the time is ripe for describing some of the recent development of superconducting devices, systems and applications. As such, the discussion of superconducting qubits and circuits is limited to devices that are proven useful for current or near future applications. Consequently, the centre of interest is the practical applications of QIP, such as computation and simulation in Physics and Chemistry.
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Affiliation(s)
- G Wendin
- Department of Microtechnology and Nanoscience-MC2, Chalmers University of Technology, SE-41296 Gothenburg, Sweden
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94
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Su Z, Tacla AB, Hocevar M, Car D, Plissard SR, Bakkers EPAM, Daley AJ, Pekker D, Frolov SM. Andreev molecules in semiconductor nanowire double quantum dots. Nat Commun 2017; 8:585. [PMID: 28928420 PMCID: PMC5605684 DOI: 10.1038/s41467-017-00665-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2016] [Accepted: 07/19/2017] [Indexed: 11/13/2022] Open
Abstract
Chains of quantum dots coupled to superconductors are promising for the realization of the Kitaev model of a topological superconductor. While individual superconducting quantum dots have been explored, control of longer chains requires understanding of interdot coupling. Here, double quantum dots are defined by gate voltages in indium antimonide nanowires. High transparency superconducting niobium titanium nitride contacts are made to each of the dots in order to induce superconductivity, as well as probe electron transport. Andreev bound states induced on each of dots hybridize to define Andreev molecular states. The evolution of these states is studied as a function of charge parity on the dots, and in magnetic field. The experiments are found in agreement with a numerical model. Quantum dots in a nanowire are one possible approach to creating a solid-state quantum simulator. Here, the authors demonstrate the coupling of electronic states in a double quantum dot to form Andreev molecule states; a potential building block for longer chains suitable for quantum simulation.
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Affiliation(s)
- Zhaoen Su
- Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, PA, 15260, USA
| | - Alexandre B Tacla
- Department of Physics and SUPA, University of Strathclyde, Glasgow, G4 0NG, UK
| | - Moïra Hocevar
- Universite Grenoble Alpes, F-38000, Grenoble, France.,CNRS, Institut Neel, F-38000, Grenoble, France
| | - Diana Car
- Department of Applied Physics, Eindhoven University of Technology, 5600 MB, Eindhoven, The Netherlands
| | | | - Erik P A M Bakkers
- Department of Applied Physics, Eindhoven University of Technology, 5600 MB, Eindhoven, The Netherlands.,QuTech and Kavli Institute of Nanoscience, Delft University of Technology, 2628 CJ, Delft, The Netherlands
| | - Andrew J Daley
- Department of Physics and SUPA, University of Strathclyde, Glasgow, G4 0NG, UK
| | - David Pekker
- Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, PA, 15260, USA
| | - Sergey M Frolov
- Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, PA, 15260, USA.
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95
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Gooth J, Borg M, Schmid H, Schaller V, Wirths S, Moselund K, Luisier M, Karg S, Riel H. Ballistic One-Dimensional InAs Nanowire Cross-Junction Interconnects. NANO LETTERS 2017; 17:2596-2602. [PMID: 28334529 DOI: 10.1021/acs.nanolett.7b00400] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Coherent interconnection of quantum bits remains an ongoing challenge in quantum information technology. Envisioned hardware to achieve this goal is based on semiconductor nanowire (NW) circuits, comprising individual NW devices that are linked through ballistic interconnects. However, maintaining the sensitive ballistic conduction and confinement conditions across NW intersections is a nontrivial problem. Here, we go beyond the characterization of a single NW device and demonstrate ballistic one-dimensional (1D) quantum transport in InAs NW cross-junctions, monolithically integrated on Si. Characteristic 1D conductance plateaus are resolved in field-effect measurements across up to four NW-junctions in series. The 1D ballistic transport and sub-band splitting is preserved for both crossing-directions. We show that the 1D modes of a single injection terminal can be distributed into multiple NW branches. We believe that NW cross-junctions are well-suited as cross-directional communication links for the reliable transfer of quantum information as required for quantum computational systems.
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Affiliation(s)
- Johannes Gooth
- IBM Research - Zurich , Säumerstrasse 4, 8803 Rüschlikon, Switzerland
| | - Mattias Borg
- IBM Research - Zurich , Säumerstrasse 4, 8803 Rüschlikon, Switzerland
| | - Heinz Schmid
- IBM Research - Zurich , Säumerstrasse 4, 8803 Rüschlikon, Switzerland
| | - Vanessa Schaller
- IBM Research - Zurich , Säumerstrasse 4, 8803 Rüschlikon, Switzerland
| | - Stephan Wirths
- IBM Research - Zurich , Säumerstrasse 4, 8803 Rüschlikon, Switzerland
| | - Kirsten Moselund
- IBM Research - Zurich , Säumerstrasse 4, 8803 Rüschlikon, Switzerland
| | - Mathieu Luisier
- ETH Zurich, Integrated Systems Laboratory , Gloriastrasse 35, 8092 Zurich, Switzerland
| | - Siegfried Karg
- IBM Research - Zurich , Säumerstrasse 4, 8803 Rüschlikon, Switzerland
| | - Heike Riel
- IBM Research - Zurich , Säumerstrasse 4, 8803 Rüschlikon, Switzerland
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96
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Dartiailh MC, Kontos T, Douçot B, Cottet A. Direct Cavity Detection of Majorana Pairs. PHYSICAL REVIEW LETTERS 2017; 118:126803. [PMID: 28388198 DOI: 10.1103/physrevlett.118.126803] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Indexed: 06/07/2023]
Abstract
No experiment could directly test the particle-antiparticle duality of Majorana fermions, so far. However, this property represents a necessary ingredient towards the realization of topological quantum computing schemes. Here, we show how to complete this task by using microwave techniques. The direct coupling between a pair of overlapping Majorana bound states and the electric field from a microwave cavity is extremely difficult to detect due to the self-adjoint character of Majorana fermions which forbids direct energy exchanges with the cavity. We show theoretically how this problem can be circumvented by using photoassisted tunneling to fermionic reservoirs. The absence of a direct microwave transition inside the Majorana pair in spite of the light-Majorana coupling would represent a smoking gun for the Majorana self-adjoint character.
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Affiliation(s)
- Matthieu C Dartiailh
- Laboratoire Pierre Aigrain, Ecole Normale Supérieure-PSL Research University, CNRS, Université Pierre et Marie Curie-Sorbonne Universités, Université Paris Diderot-Sorbonne Paris Cité, 24 rue Lhomond, 75231 Paris Cedex 05, France
| | - Takis Kontos
- Laboratoire Pierre Aigrain, Ecole Normale Supérieure-PSL Research University, CNRS, Université Pierre et Marie Curie-Sorbonne Universités, Université Paris Diderot-Sorbonne Paris Cité, 24 rue Lhomond, 75231 Paris Cedex 05, France
| | - Benoit Douçot
- Sorbonne Universités, Université Pierre et Marie Curie, CNRS, LPTHE, UMR 7589, 4 place Jussieu, 75252 Paris Cedex 05, France
| | - Audrey Cottet
- Laboratoire Pierre Aigrain, Ecole Normale Supérieure-PSL Research University, CNRS, Université Pierre et Marie Curie-Sorbonne Universités, Université Paris Diderot-Sorbonne Paris Cité, 24 rue Lhomond, 75231 Paris Cedex 05, France
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97
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Sherman D, Yodh JS, Albrecht SM, Nygård J, Krogstrup P, Marcus CM. Normal, superconducting and topological regimes of hybrid double quantum dots. NATURE NANOTECHNOLOGY 2017; 12:212-217. [PMID: 27842064 DOI: 10.1038/nnano.2016.227] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Accepted: 09/19/2016] [Indexed: 06/06/2023]
Abstract
Epitaxial semiconductor-superconductor hybrid materials are an excellent basis for studying mesoscopic and topological superconductivity, as the semiconductor inherits a hard superconducting gap while retaining tunable carrier density. Here, we investigate double-quantum-dot structures made from InAs nanowires with a patterned epitaxial Al two-facet shell that proximitizes two gate-defined segments along the nanowire. We follow the evolution of mesoscopic superconductivity and charging energy in this system as a function of magnetic field and voltage-tuned barriers. Interdot coupling is varied from strong to weak using side gates, and the ground state is varied between normal, superconducting and topological regimes by applying a magnetic field. We identify the topological transition by tracking the spacing between successive co-tunnelling peaks as a function of axial magnetic field and show that the individual dots host weakly hybridized Majorana modes.
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Affiliation(s)
- D Sherman
- Center for Quantum Devices and Station Q Copenhagen, Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
| | - J S Yodh
- Center for Quantum Devices and Station Q Copenhagen, Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
| | - S M Albrecht
- Center for Quantum Devices and Station Q Copenhagen, Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
| | - J Nygård
- Center for Quantum Devices and Station Q Copenhagen, Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
| | - P Krogstrup
- Center for Quantum Devices and Station Q Copenhagen, Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
| | - C M Marcus
- Center for Quantum Devices and Station Q Copenhagen, Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
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98
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Chen IJ, Lehmann S, Nilsson M, Kivisaari P, Linke H, Dick KA, Thelander C. Conduction Band Offset and Polarization Effects in InAs Nanowire Polytype Junctions. NANO LETTERS 2017; 17:902-908. [PMID: 28002673 DOI: 10.1021/acs.nanolett.6b04211] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Although zinc-blende (ZB) and wurtzite (WZ) structures differ only in the atomic stacking sequence, mixing of crystal phases can strongly affect the electronic properties, a problem particularly common to bottom up-grown nanostructures. A lack of understanding of the nature of electronic transport at crystal phase junctions thus severely limits our ability to develop functional nanowire devices. In this work we investigated electron transport in InAs nanowires with designed mixing of crystal structures, ZB/WZ/ZB, by temperature-dependent electrical measurements. The WZ inclusion gives rise to an energy barrier in the conduction band. Interpreting the experimental result in terms of thermionic emission and using a drift-diffusion model, we extracted values for the WZ/ZB band offset, 135 ± 10 meV, and interface sheet polarization charge density on the order of 10-3 C/m2. The extracted polarization charge density is 1-2 orders of magnitude smaller than previous experimental results, but in good agreement with first principle calculation of spontaneous polarization in WZ InAs. When the WZ length is reduced below 20 nm, an effective barrier lowering is observed, indicating the increasing importance of tunneling transport. Finally, we found that band-bending at ZB/WZ junctions can lead to bound electron states within an enclosed WZ segment of sufficient length, evidenced by our observation of Coulomb blockade at low temperature. These findings provide critical input for modeling and designing the electronic properties of novel functional devices, such as nanowire transistors, where crystal polytypes are commonly found.
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Affiliation(s)
- I-Ju Chen
- Solid State Physics and NanoLund and ‡Center for Analysis and Synthesis, Lund University , S-221 00 Lund, Sweden
| | - Sebastian Lehmann
- Solid State Physics and NanoLund and ‡Center for Analysis and Synthesis, Lund University , S-221 00 Lund, Sweden
| | - Malin Nilsson
- Solid State Physics and NanoLund and ‡Center for Analysis and Synthesis, Lund University , S-221 00 Lund, Sweden
| | - Pyry Kivisaari
- Solid State Physics and NanoLund and ‡Center for Analysis and Synthesis, Lund University , S-221 00 Lund, Sweden
| | - Heiner Linke
- Solid State Physics and NanoLund and ‡Center for Analysis and Synthesis, Lund University , S-221 00 Lund, Sweden
| | - Kimberly A Dick
- Solid State Physics and NanoLund and ‡Center for Analysis and Synthesis, Lund University , S-221 00 Lund, Sweden
| | - Claes Thelander
- Solid State Physics and NanoLund and ‡Center for Analysis and Synthesis, Lund University , S-221 00 Lund, Sweden
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99
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Kim BK, Kim HS, Yang Y, Peng X, Yu D, Doh YJ. Strong Superconducting Proximity Effects in PbS Semiconductor Nanowires. ACS NANO 2017; 11:221-226. [PMID: 28051853 DOI: 10.1021/acsnano.6b04774] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We report the fabrication of strongly coupled nanohybrid superconducting junctions using PbS semiconductor nanowires and Pb0.5In0.5 superconducting electrodes. The maximum supercurrent in the junction reaches up to ∼15 μA at 0.3 K, which is the highest value ever observed in semiconductor-nanowire-based superconducting junctions. The observation of microwave-induced constant voltage steps confirms the existence of genuine Josephson coupling through the nanowire. Monotonic suppression of the critical current under an external magnetic field is also in good agreement with the narrow junction model. The temperature-dependent stochastic distribution of the switching current exhibits a crossover from phase diffusion to a thermal activation process as the temperature decreases. These strongly coupled nanohybrid superconducting junctions would be advantageous to the development of gate-tunable superconducting quantum information devices.
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Affiliation(s)
- Bum-Kyu Kim
- Department of Physics and Photon Science, Gwangju Institute of Science and Technology (GIST) , Gwangju 61005, Korea
| | - Hong-Seok Kim
- Department of Physics and Photon Science, Gwangju Institute of Science and Technology (GIST) , Gwangju 61005, Korea
| | - Yiming Yang
- Department of Physics, University of California , Davis, California 95616, United States
| | - Xingyue Peng
- Department of Physics, University of California , Davis, California 95616, United States
| | - Dong Yu
- Department of Physics, University of California , Davis, California 95616, United States
| | - Yong-Joo Doh
- Department of Physics and Photon Science, Gwangju Institute of Science and Technology (GIST) , Gwangju 61005, Korea
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100
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Hals KMD, Schecter M, Rudner MS. Composite Topological Excitations in Ferromagnet-Superconductor Heterostructures. PHYSICAL REVIEW LETTERS 2016; 117:017001. [PMID: 27419584 DOI: 10.1103/physrevlett.117.017001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Indexed: 06/06/2023]
Abstract
We investigate the formation of a new type of composite topological excitation-the Skyrmion-vortex pair (SVP)-in hybrid systems consisting of coupled ferromagnetic and superconducting layers. Spin-orbit interaction in the superconductor mediates a magnetoelectric coupling between the vortex and the Skyrmion, with a sign (attractive or repulsive) that depends on the topological indices of the constituents. We determine the conditions under which a bound SVP is formed and characterize the range and depth of the effective binding potential through analytical estimates and numerical simulations. Furthermore, we develop a semiclassical description of the coupled Skyrmion-vortex dynamics and discuss how SVPs can be controlled by applied spin currents.
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Affiliation(s)
- Kjetil M D Hals
- Niels Bohr International Academy, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
- The Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Michael Schecter
- The Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Mark S Rudner
- Niels Bohr International Academy, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
- The Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
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