1
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Niu C, Wang M, Zhang Z, Qiu G, Wang Y, Zheng D, Liao PY, Wu W, Ye PD. Superconducting Field-Effect Transistors with Pd xTe-Te Intimate Contacts. ACS NANO 2024; 18:15107-15113. [PMID: 38819119 DOI: 10.1021/acsnano.4c02352] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2024]
Abstract
Superconducting-based electronic devices have shown great potential for future quantum computing applications. One key building block device is a superconducting field-effect transistor based on a superconductor-semiconductor-superconductor Josephson-junction (JJ) with a gate-tunable semiconducting channel. However, the performance of such devices is highly dependent on the quality of the superconductor to semiconductor interface. In this study, we present an alternative method to obtain a high-quality interface by using intimate contact. We investigate the proximity-induced superconductivity in chiral crystal tellurium (Te) and fabricate a PdxTe-Te-PdxTe JJ with an ambipolar supercurrent that is gate-tunable and exhibits multiple Andreev reflections. The semiconducting two-dimensional Te single crystal is grown hydrothermally and partially converted to superconducting PdxTe by controlled annealing. Our work demonstrates a promising path for realizing controllable superconducting electronic devices with high-quality superconducting interfaces; thus, we can continue to advance the field of quantum computing and other interface-based technologies.
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Affiliation(s)
- Chang Niu
- Elmore Family School of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47907, United States
- Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907, United States
| | - Mingyi Wang
- School of Industrial Engineering, Purdue University, West Lafayette, Indiana 47907, United States
| | - Zhuocheng Zhang
- Elmore Family School of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47907, United States
- Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907, United States
| | - Gang Qiu
- Elmore Family School of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47907, United States
- Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907, United States
| | - Yixiu Wang
- School of Industrial Engineering, Purdue University, West Lafayette, Indiana 47907, United States
| | - Dongqi Zheng
- Elmore Family School of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47907, United States
- Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907, United States
| | - Pai-Ying Liao
- Elmore Family School of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47907, United States
- Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907, United States
| | - Wenzhuo Wu
- School of Industrial Engineering, Purdue University, West Lafayette, Indiana 47907, United States
| | - Peide D Ye
- Elmore Family School of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47907, United States
- Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907, United States
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2
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Jeon Y, Kim S, Seo J, Yoo H. Contributions of Light to Novel Logic Concepts Using Optoelectronic Materials. SMALL METHODS 2024; 8:e2300391. [PMID: 37231569 DOI: 10.1002/smtd.202300391] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Revised: 04/29/2023] [Indexed: 05/27/2023]
Abstract
Instead of the current method of transmitting voltage or current signals in electronic circuit operation, light offers an alternative to conventional logic, allowing for the implementation of new logic concepts through interaction with light. This manuscript examines the use of light in implementing new logic concepts as an alternative to traditional logic circuits and as a future technology. This article provides an overview of how to implement logic operations using light rather than voltage or current signals using optoelectronic materials such as 2D materials, metal-oxides, carbon structures, polymers, small molecules, and perovskites. This review covers the various technologies and applications of using light to dope devices, implement logic gates, control logic circuits, and generate light as an output signal. Recent research on logic and the use of light to implement new functions is summarized. This review also highlights the potential of optoelectronic logic for future technological advancements.
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Affiliation(s)
- Yunchae Jeon
- Department of Electronic Engineering, Gachon University, 1342 Seongnam-daero, Seongnam, 13120, Republic of Korea
| | - Somi Kim
- Department of Electronic Engineering, Gachon University, 1342 Seongnam-daero, Seongnam, 13120, Republic of Korea
| | - Juhyung Seo
- Department of Electronic Engineering, Gachon University, 1342 Seongnam-daero, Seongnam, 13120, Republic of Korea
| | - Hocheon Yoo
- Department of Electronic Engineering, Gachon University, 1342 Seongnam-daero, Seongnam, 13120, Republic of Korea
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3
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Yu S, Chen L, Pan Y, Wang Y, Zhang D, Wu G, Fan X, Liu X, Wu L, Zhang L, Peng W, Ren J, Wang Z. Gate-Tunable Critical Current of the Three-Dimensional Niobium Nanobridge Josephson Junction. NANO LETTERS 2023; 23:8043-8049. [PMID: 37592211 DOI: 10.1021/acs.nanolett.3c02015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/19/2023]
Abstract
Recent studies have shown that the critical currents of several metallic superconducting nanowires and Dayem bridges can be locally tuned by using a gate voltage (Vg). Here, we report a gate-tunable Josephson junction structure constructed from a three-dimensional (3D) niobium nanobridge junction (NBJ) with a voltage gate on top. Measurements up to 6 K showed that the critical current of this structure can be tuned to zero by increasing Vg. The critical gate voltage was reduced to 16 V and may possibly be reduced further by reducing the thickness of the insulation layer between the gate and the NBJ. Furthermore, the flux modulation generated by Josephson interference of two parallel 3D NBJs can also be tuned by using Vg in a similar manner. Therefore, we believe that this gate-tunable Josephson junction structure is promising for superconducting circuit fabrication at high integration levels.
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Affiliation(s)
- Shujie Yu
- National Key Laboratory of Materials for Integrated Circuits, Shanghai Institute of Microsystem and Information Technology(SIMIT), Chinese Academy of Sciences, Shanghai 200050, China
- University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Lei Chen
- National Key Laboratory of Materials for Integrated Circuits, Shanghai Institute of Microsystem and Information Technology(SIMIT), Chinese Academy of Sciences, Shanghai 200050, China
- University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Yinping Pan
- National Key Laboratory of Materials for Integrated Circuits, Shanghai Institute of Microsystem and Information Technology(SIMIT), Chinese Academy of Sciences, Shanghai 200050, China
| | - Yue Wang
- National Key Laboratory of Materials for Integrated Circuits, Shanghai Institute of Microsystem and Information Technology(SIMIT), Chinese Academy of Sciences, Shanghai 200050, China
- University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Denghui Zhang
- National Key Laboratory of Materials for Integrated Circuits, Shanghai Institute of Microsystem and Information Technology(SIMIT), Chinese Academy of Sciences, Shanghai 200050, China
- University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Guangting Wu
- National Key Laboratory of Materials for Integrated Circuits, Shanghai Institute of Microsystem and Information Technology(SIMIT), Chinese Academy of Sciences, Shanghai 200050, China
- University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Xinxin Fan
- National Key Laboratory of Materials for Integrated Circuits, Shanghai Institute of Microsystem and Information Technology(SIMIT), Chinese Academy of Sciences, Shanghai 200050, China
- University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Xiaoyu Liu
- National Key Laboratory of Materials for Integrated Circuits, Shanghai Institute of Microsystem and Information Technology(SIMIT), Chinese Academy of Sciences, Shanghai 200050, China
| | - Ling Wu
- National Key Laboratory of Materials for Integrated Circuits, Shanghai Institute of Microsystem and Information Technology(SIMIT), Chinese Academy of Sciences, Shanghai 200050, China
| | - Lu Zhang
- National Key Laboratory of Materials for Integrated Circuits, Shanghai Institute of Microsystem and Information Technology(SIMIT), Chinese Academy of Sciences, Shanghai 200050, China
- University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Wei Peng
- National Key Laboratory of Materials for Integrated Circuits, Shanghai Institute of Microsystem and Information Technology(SIMIT), Chinese Academy of Sciences, Shanghai 200050, China
- University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Jie Ren
- National Key Laboratory of Materials for Integrated Circuits, Shanghai Institute of Microsystem and Information Technology(SIMIT), Chinese Academy of Sciences, Shanghai 200050, China
- University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Zhen Wang
- National Key Laboratory of Materials for Integrated Circuits, Shanghai Institute of Microsystem and Information Technology(SIMIT), Chinese Academy of Sciences, Shanghai 200050, China
- University of the Chinese Academy of Sciences, Beijing 100049, China
- School of Physical Science and Technology, Shanghai Tech University, Shanghai 200031, China
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4
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Schwarz M, Vethaak TD, Derycke V, Francheteau A, Iniguez B, Kataria S, Kloes A, Lefloch F, Lemme M, Snyder JP, Weber WM, Calvet LE. The Schottky barrier transistor in emerging electronic devices. NANOTECHNOLOGY 2023; 34:352002. [PMID: 37100049 DOI: 10.1088/1361-6528/acd05f] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Accepted: 04/25/2023] [Indexed: 06/16/2023]
Abstract
This paper explores how the Schottky barrier (SB) transistor is used in a variety of applications and material systems. A discussion of SB formation, current transport processes, and an overview of modeling are first considered. Three discussions follow, which detail the role of SB transistors in high performance, ubiquitous and cryogenic electronics. For high performance computing, the SB typically needs to be minimized to achieve optimal performance and we explore the methods adopted in carbon nanotube technology and two-dimensional electronics. On the contrary for ubiquitous electronics, the SB can be used advantageously in source-gated transistors and reconfigurable field-effect transistors (FETs) for sensors, neuromorphic hardware and security applications. Similarly, judicious use of an SB can be an asset for applications involving Josephson junction FETs.
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Affiliation(s)
| | - Tom D Vethaak
- Department of Microtechnology and Nanoscience, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden
| | - Vincent Derycke
- Université Paris-Saclay, CEA, CNRS, NIMBE, LICSEN, Gif-sur-Yvette, F-91191, France
| | | | | | | | | | - Francois Lefloch
- University Grenoble Alps, GINP, CEA-IRIG-PHELIQS, Grenoble, France
| | | | | | - Walter M Weber
- Technische Universität Wien, Institute of Solid State Electronics, Vienna, Austria
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5
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Cook J, Mardanya S, Lu Q, Conner C, Snyder M, Zhang X, McMillen J, Watson G, Chang TR, Bian G. Observation of Gapped Topological Surface States and Isolated Surface Resonances in PdTe 2 Ultrathin Films. NANO LETTERS 2023; 23:1752-1757. [PMID: 36825889 DOI: 10.1021/acs.nanolett.2c04511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
The superconductor PdTe2 is known to host bulk Dirac bands and topological surface states. The coexistence of superconductivity and topological surface states makes PdTe2 a promising platform for exploring topological superconductivity and Majorana bound states. In this work, we report the spectroscopic characterization of ultrathin PdTe2 films with thickness down to three monolayers (ML). In the 3 ML PdTe2 film, we observed spin-polarized surface resonance states, which are isolated from the bulk bands due to the quantum size effects. In addition, the hybridization of surface states on opposite faces leads to a thickness-dependent gap in the topological surface Dirac bands. Our photoemission results show clearly that the size of the hybridization gap increases as the film thickness is reduced. The observation of isolated surface resonances and gapped topological surface states sheds light on the applications of PdTe2 quantum films in spintronics and topological quantum computation.
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Affiliation(s)
- Jacob Cook
- Department of Physics and Astronomy, University of Missouri, Columbia, Missouri 65211, United States
| | - Sougata Mardanya
- Department of Physics, National Cheng Kung University, Tainan 701, Taiwan
| | - Qiangsheng Lu
- Department of Physics and Astronomy, University of Missouri, Columbia, Missouri 65211, United States
| | - Clayton Conner
- Department of Physics and Astronomy, University of Missouri, Columbia, Missouri 65211, United States
| | - Matthew Snyder
- Department of Physics and Astronomy, University of Missouri, Columbia, Missouri 65211, United States
| | - Xiaoqian Zhang
- Department of Physics and Astronomy, University of Missouri, Columbia, Missouri 65211, United States
| | - James McMillen
- Department of Physics and Astronomy, University of Missouri, Columbia, Missouri 65211, United States
| | - Geoff Watson
- Department of Physics and Astronomy, University of Missouri, Columbia, Missouri 65211, United States
| | - Tay-Rong Chang
- Department of Physics, National Cheng Kung University, Tainan 701, Taiwan
- Center for Quantum Frontiers of Research and Technology (QFort), Tainan 70101, Taiwan
- Physics Division, National Center for Theoretical Sciences, Taipei 10617, Taiwan
| | - Guang Bian
- Department of Physics and Astronomy, University of Missouri, Columbia, Missouri 65211, United States
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6
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Catto G, Liu W, Kundu S, Lahtinen V, Vesterinen V, Möttönen M. Microwave response of a metallic superconductor subject to a high-voltage gate electrode. Sci Rep 2022; 12:6822. [PMID: 35474123 PMCID: PMC9042855 DOI: 10.1038/s41598-022-10833-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Accepted: 04/11/2022] [Indexed: 11/11/2022] Open
Abstract
Processes that lead to the critical-current suppression and change of impedance of a superconductor under the application of an external voltage is an active area of research, especially due to various possible technological applications. In particular, field-effect transistors and radiation detectors have been developed in the recent years, showing the potential for precision and sensitivity exceeding their normal-metal counterparts. In order to describe the phenomenon that leads to the critical-current suppression in metallic superconducting structures, a field-effect hypothesis has been formulated, stating that an electric field can penetrate the metallic superconductor and affect its characteristics. The existence of such an effect would imply the incompleteness of the underlying theory, and hence indicate an important gap in the general comprehension of superconductors. In addition to its theoretical value, a complete understanding of the phenomenon underneath the electric-field response of the superconductor is important in the light of the related technological applications. In this paper, we study the change of the characteristics of a superconductor implementing a coplanar-waveguide resonator as a tank circuit, by relating our measurements to the reactance and resistance of the material. Namely, we track the state of the superconductor at different voltages and resulting leakage currents of a nearby gate electrode which is not galvanically connected to the resonator. By comparing the effects of the leakage current and of a change in the temperature of the system, we conclude that the observed behaviour in the superconductor is mainly caused by the heat that is deposited by the leakage current, and bearing the experimental uncertainties, we are not able to observe the effect of the applied electric field in our sample. In addition, we present a relatively good quantitative agreement between the Mattis–Bardeen theory of a heated superconductor and the experimental observations. Importantly, we do not claim this work to nullify the results of previous works, but rather to provide inspiration for future more thorough experiments and analysis using the methods presented here.
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Affiliation(s)
- Giacomo Catto
- QCD Labs, QTF Centre of Excellence, Department of Applied Physics, Aalto University, P.O. Box 13500, 00076, Aalto, Finland.
| | - Wei Liu
- QCD Labs, QTF Centre of Excellence, Department of Applied Physics, Aalto University, P.O. Box 13500, 00076, Aalto, Finland. .,IQM, Keilaranta 19, 02150, Espoo, Finland.
| | - Suman Kundu
- QCD Labs, QTF Centre of Excellence, Department of Applied Physics, Aalto University, P.O. Box 13500, 00076, Aalto, Finland
| | - Valtteri Lahtinen
- QCD Labs, QTF Centre of Excellence, Department of Applied Physics, Aalto University, P.O. Box 13500, 00076, Aalto, Finland
| | - Visa Vesterinen
- QTF Centre of Excellence, VTT Technical Research Centre of Finland Ltd, P.O. Box 1000, 02044, Espoo, Finland
| | - Mikko Möttönen
- QCD Labs, QTF Centre of Excellence, Department of Applied Physics, Aalto University, P.O. Box 13500, 00076, Aalto, Finland.,QTF Centre of Excellence, VTT Technical Research Centre of Finland Ltd, P.O. Box 1000, 02044, Espoo, Finland
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7
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Orús P, Sigloch F, Sangiao S, De Teresa JM. Superconducting Materials and Devices Grown by Focused Ion and Electron Beam Induced Deposition. NANOMATERIALS 2022; 12:nano12081367. [PMID: 35458074 PMCID: PMC9029853 DOI: 10.3390/nano12081367] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Revised: 04/11/2022] [Accepted: 04/13/2022] [Indexed: 01/27/2023]
Abstract
Since its discovery in 1911, superconductivity has represented an equally inciting and fascinating field of study in several areas of physics and materials science, ranging from its most fundamental theoretical understanding, to its practical application in different areas of engineering. The fabrication of superconducting materials can be downsized to the nanoscale by means of Focused Ion/Electron Beam Induced Deposition: nanopatterning techniques that make use of a focused beam of ions or electrons to decompose a gaseous precursor in a single step. Overcoming the need to use a resist, these approaches allow for targeted, highly-flexible nanopatterning of nanostructures with lateral resolution in the range of 10 nm to 30 nm. In this review, the fundamentals of these nanofabrication techniques are presented, followed by a literature revision on the published work that makes use of them to grow superconducting materials, the most remarkable of which are based on tungsten, niobium, molybdenum, carbon, and lead. Several examples of the application of these materials to functional devices are presented, related to the superconducting proximity effect, vortex dynamics, electric-field effect, and to the nanofabrication of Josephson junctions and nanoSQUIDs. Owing to the patterning flexibility they offer, both of these techniques represent a powerful and convenient approach towards both fundamental and applied research in superconductivity.
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Affiliation(s)
- Pablo Orús
- Instituto de Nanociencia y Materiales de Aragón (INMA), CSIC-Universidad de Zaragoza, 50009 Zaragoza, Spain; (P.O.); (F.S.); (S.S.)
| | - Fabian Sigloch
- Instituto de Nanociencia y Materiales de Aragón (INMA), CSIC-Universidad de Zaragoza, 50009 Zaragoza, Spain; (P.O.); (F.S.); (S.S.)
| | - Soraya Sangiao
- Instituto de Nanociencia y Materiales de Aragón (INMA), CSIC-Universidad de Zaragoza, 50009 Zaragoza, Spain; (P.O.); (F.S.); (S.S.)
- Departamento de Física de la Materia Condensada, Facultad de Ciencias, Universidad de Zaragoza, 50009 Zaragoza, Spain
- Laboratorio de Microscopías Avanzadas (LMA), University of Zaragoza, 50018 Zaragoza, Spain
| | - José María De Teresa
- Instituto de Nanociencia y Materiales de Aragón (INMA), CSIC-Universidad de Zaragoza, 50009 Zaragoza, Spain; (P.O.); (F.S.); (S.S.)
- Departamento de Física de la Materia Condensada, Facultad de Ciencias, Universidad de Zaragoza, 50009 Zaragoza, Spain
- Laboratorio de Microscopías Avanzadas (LMA), University of Zaragoza, 50018 Zaragoza, Spain
- Correspondence:
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8
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Ritter MF, Crescini N, Haxell DZ, Hinderling M, Riel H, Bruder C, Fuhrer A, Nichele F. Out-of-equilibrium phonons in gated superconducting switches. NATURE ELECTRONICS 2022; 5:71-77. [PMID: 35310295 PMCID: PMC8885403 DOI: 10.1038/s41928-022-00721-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Accepted: 01/19/2022] [Indexed: 06/13/2023]
Abstract
Recent experiments have suggested that superconductivity in metallic nanowires can be suppressed by the application of modest gate voltages. The source of this gate action has been debated and either attributed to an electric-field effect or to small leakage currents. Here we show that the suppression of superconductivity in titanium nitride nanowires on silicon substrates does not depend on the presence or absence of an electric field at the nanowire, but requires a current of high-energy electrons. The suppression is most efficient when electrons are injected into the nanowire, but similar results are obtained when electrons are passed between two remote electrodes. This is explained by the decay of high-energy electrons into phonons, which propagate through the substrate and affect superconductivity in the nanowire by generating quasiparticles. By studying the switching probability distribution of the nanowire, we also show that high-energy electron emission leads to a much broader phonon energy distribution compared with the case where superconductivity is suppressed by Joule heating near the nanowire.
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Affiliation(s)
- M. F. Ritter
- IBM Quantum, IBM Research—Zurich, Rüschlikon, Switzerland
| | - N. Crescini
- IBM Quantum, IBM Research—Zurich, Rüschlikon, Switzerland
| | - D. Z. Haxell
- IBM Quantum, IBM Research—Zurich, Rüschlikon, Switzerland
| | - M. Hinderling
- IBM Quantum, IBM Research—Zurich, Rüschlikon, Switzerland
| | - H. Riel
- IBM Quantum, IBM Research—Zurich, Rüschlikon, Switzerland
| | - C. Bruder
- Department of Physics, University of Basel, Basel, Switzerland
| | - A. Fuhrer
- IBM Quantum, IBM Research—Zurich, Rüschlikon, Switzerland
| | - F. Nichele
- IBM Quantum, IBM Research—Zurich, Rüschlikon, Switzerland
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9
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Paolucci F, Crisá F, De Simoni G, Bours L, Puglia C, Strambini E, Roddaro S, Giazotto F. Electrostatic Field-Driven Supercurrent Suppression in Ionic-Gated Metallic Superconducting Nanotransistors. NANO LETTERS 2021; 21:10309-10314. [PMID: 34851117 DOI: 10.1021/acs.nanolett.1c03481] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Recent experiments have shown the possibility of tuning the transport properties of metallic nanosized superconductors through a gate voltage. These results renewed the longstanding debate on the interaction between electrostatic fields and superconductivity. Indeed, different works suggested competing mechanisms as the cause of the effect: an unconventional electric field-effect or quasiparticle injection. Here, we provide conclusive evidence for the electrostatic-field-driven control of the supercurrent in metallic nanosized superconductors, by realizing ionic-gated superconducting field-effect nanotransistors (ISFETs) where electron injection is impossible. Our Nb ISFETs show giant suppression of the superconducting critical current of up to ∼45%. Moreover, the bipolar supercurrent suppression observed in different ISFETs, together with invariant critical temperature and normal-state resistance, also excludes conventional charge accumulation/depletion. Therefore, the microscopic explanation of this effect calls upon a novel theory able to describe the nontrivial interaction of static electric fields with conventional superconductivity.
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Affiliation(s)
- Federico Paolucci
- NEST, Istituto Nanoscienze-CNR and Scuola Normale Superiore, Piazza San Silvestro 12, I-56127 Pisa, Italy
| | - Francesco Crisá
- Department of Physics "E. Fermi", Universitá di Pisa, Largo Pontecorvo 3, I-56127 Pisa, Italy
| | - Giorgio De Simoni
- NEST, Istituto Nanoscienze-CNR and Scuola Normale Superiore, Piazza San Silvestro 12, I-56127 Pisa, Italy
| | - Lennart Bours
- NEST, Istituto Nanoscienze-CNR and Scuola Normale Superiore, Piazza San Silvestro 12, I-56127 Pisa, Italy
| | - Claudio Puglia
- NEST, Istituto Nanoscienze-CNR and Scuola Normale Superiore, Piazza San Silvestro 12, I-56127 Pisa, Italy
| | - Elia Strambini
- NEST, Istituto Nanoscienze-CNR and Scuola Normale Superiore, Piazza San Silvestro 12, I-56127 Pisa, Italy
| | - Stefano Roddaro
- Department of Physics "E. Fermi", Universitá di Pisa, Largo Pontecorvo 3, I-56127 Pisa, Italy
| | - Francesco Giazotto
- NEST, Istituto Nanoscienze-CNR and Scuola Normale Superiore, Piazza San Silvestro 12, I-56127 Pisa, Italy
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10
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De Simoni G, Battisti S, Ligato N, Mercaldo MT, Cuoco M, Giazotto F. Gate Control of the Current-Flux Relation of a Josephson Quantum Interferometer Based on Proximitized Metallic Nanojuntions. ACS APPLIED ELECTRONIC MATERIALS 2021; 3:3927-3935. [PMID: 36247495 PMCID: PMC9555709 DOI: 10.1021/acsaelm.1c00508] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
We demonstrate an Al superconducting quantum interference device in which the Josephson junctions are implemented through gate-controlled proximity Cu mesoscopic weak links. This specific kind of metallic weak links behaves analogously to genuine superconducting metals in terms of the response to electrostatic gating and provides a good performance in terms of current-modulation visibility. We show that through the application of a static gate voltage we can modify the interferometer current-flux relation in a fashion that seems compatible with the introduction of π-channels within the gated weak link. Our results suggest that the microscopic mechanism at the origin of the suppression of the switching current in the interferometer is apparently phase coherent, resulting in an overall damping of the superconducting phase rigidity. We finally tackle the performance of the interferometer in terms of responsivity to magnetic flux variations in the dissipative regime and discuss the practical relevance of gated proximity-based all-metallic SQUIDs for magnetometry at the nanoscale.
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Affiliation(s)
- Giorgio De Simoni
- NEST,
Istituto Nanoscienze-CNR and Scuola Normale Superiore, I-56127 Pisa, Italy
| | - Sebastiano Battisti
- NEST,
Istituto Nanoscienze-CNR and Scuola Normale Superiore, I-56127 Pisa, Italy
- Department
of Physics “E. Fermi”, Universitá
di Pisa, Largo Pontecorvo
3, I-56127 Pisa, Italy
| | - Nadia Ligato
- NEST,
Istituto Nanoscienze-CNR and Scuola Normale Superiore, I-56127 Pisa, Italy
| | - Maria Teresa Mercaldo
- Dipartimento
di Fisica “E. R. Caianiello”, Universitá di Salerno, Fisciano, Salerno IT-84084, Italy
| | | | - Francesco Giazotto
- NEST,
Istituto Nanoscienze-CNR and Scuola Normale Superiore, I-56127 Pisa, Italy
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11
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Orús P, Fomin VM, De Teresa JM, Córdoba R. Critical current modulation induced by an electric field in superconducting tungsten-carbon nanowires. Sci Rep 2021; 11:17698. [PMID: 34489493 PMCID: PMC8421514 DOI: 10.1038/s41598-021-97075-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Accepted: 08/18/2021] [Indexed: 11/08/2022] Open
Abstract
The critical current of a superconducting nanostructure can be suppressed by applying an electric field in its vicinity. This phenomenon is investigated throughout the fabrication and electrical characterization of superconducting tungsten-carbon (W-C) nanostructures grown by Ga[Formula: see text] focused ion beam induced deposition (FIBID). In a 45 nm-wide, 2.7 [Formula: see text]m-long W-C nanowire, an increasing side-gate voltage is found to progressively reduce the critical current of the device, down to a full suppression of the superconducting state below its critical temperature. This modulation is accounted for by the squeezing of the superconducting current by the electric field within a theoretical model based on the Ginzburg-Landau theory, in agreement with experimental data. Compared to electron beam lithography or sputtering, the single-step FIBID approach provides with enhanced patterning flexibility and yields nanodevices with figures of merit comparable to those retrieved in other superconducting materials, including Ti, Nb, and Al. Exhibiting a higher critical temperature than most of other superconductors, in which this phenomenon has been observed, as well as a reduced critical value of the gate voltage required to fully suppress superconductivity, W-C deposits are strong candidates for the fabrication of nanodevices based on the electric field-induced superconductivity modulation.
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Affiliation(s)
- Pablo Orús
- Instituto de Nanociencia y Materiales de Aragón (INMA), CSIC-Universidad de Zaragoza, 50009, Zaragoza, Spain
- Departamento de Física de la Materia Condensada, Facultad de Ciencias, Universidad de Zaragoza, 50009, Zaragoza, Spain
| | - Vladimir M Fomin
- Institute for Integrative Nanosciences (IIN), Leibniz Institute for Solid State and Material Research (IFW) Dresden, Helmholtzstraße 20, 01069, Dresden, Germany
- Laboratory of Physics and Engineering of Nanomaterials, Department of Theoretical Physics, Moldova State University, Strada A. Mateevici 60, 2009, Chişinău, Republic of Moldova
- Institute of Engineering Physics for Biomedicine, National Research Nuclear University MEPhI, Kashirskoe shosse 31, Moscow, 115409, Russia
| | - José María De Teresa
- Instituto de Nanociencia y Materiales de Aragón (INMA), CSIC-Universidad de Zaragoza, 50009, Zaragoza, Spain.
- Departamento de Física de la Materia Condensada, Facultad de Ciencias, Universidad de Zaragoza, 50009, Zaragoza, Spain.
- Laboratorio de Microscopías Avanzadas (LMA), University of Zaragoza, 50018, Zaragoza, Spain.
| | - Rosa Córdoba
- Instituto de Ciencia Molecular (ICMol), Universitat de València, 46980, Paterna, Spain.
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12
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Golokolenov I, Guthrie A, Kafanov S, Pashkin YA, Tsepelin V. On the origin of the controversial electrostatic field effect in superconductors. Nat Commun 2021; 12:2747. [PMID: 33980842 PMCID: PMC8115342 DOI: 10.1038/s41467-021-22998-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Accepted: 03/30/2021] [Indexed: 11/09/2022] Open
Abstract
Superconducting quantum devices offer numerous applications, from electrical metrology and magnetic sensing to energy-efficient high-end computing and advanced quantum information processing. The key elements of quantum circuits are (single and double) Josephson junctions controllable either by electric current or magnetic field. The voltage control, commonly used in semiconductor-based devices via the electrostatic field effect, would be far more versatile and practical. Hence, the field effect recently reported in superconducting devices may revolutionise the whole field of superconductor electronics provided it is confirmed. Here we show that the suppression of the critical current attributed to the field effect, can be explained by quasiparticle excitations in the constriction of superconducting devices. Our results demonstrate that a miniscule leakage current between the gate and the constriction of devices perfectly follows the Fowler-Nordheim model of electron field emission from a metal electrode and injects quasiparticles with energies sufficient to weaken or even suppress superconductivity. A recent report on electrostatic field effect in superconducting devices provides a high potential for advanced quantum technology, but it remains controversial. Here, the authors report that the suppression of critical current, which was attributed to the field effect, can instead be explained by quasiparticle excitations in the constriction of superconducting devices.
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Affiliation(s)
- I Golokolenov
- Department of Physics, Lancaster University, Lancaster, UK.,P. L. Kapitza Institute for Physical Problems of RAS, Moscow, Russia.,National Research University Higher School of Economics, Moscow, Russia
| | - A Guthrie
- Department of Physics, Lancaster University, Lancaster, UK
| | - S Kafanov
- Department of Physics, Lancaster University, Lancaster, UK.
| | - Yu A Pashkin
- Department of Physics, Lancaster University, Lancaster, UK.
| | - V Tsepelin
- Department of Physics, Lancaster University, Lancaster, UK
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13
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Solinas P, Amoretti A, Giazotto F. Sauter-Schwinger Effect in a Bardeen-Cooper-Schrieffer Superconductor. PHYSICAL REVIEW LETTERS 2021; 126:117001. [PMID: 33798345 DOI: 10.1103/physrevlett.126.117001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 12/01/2020] [Accepted: 02/18/2021] [Indexed: 06/12/2023]
Abstract
Since the 1960s a deep and surprising connection has followed the development of superconductivity and quantum field theory. The Anderson-Higgs mechanism and the similarities between the Dirac and Bogoliubov-de Gennes equations are the most intriguing examples. In this last analogy, the massive Dirac particle is identified with a quasiparticle excitation and the fermion mass energy with the superconducting gap energy. Here we follow further this parallelism and show that it predicts an outstanding phenomenon: the superconducting Sauter-Schwinger effect. As in the quantum electrodynamics Schwinger effect, where an electron-positron couple is created from the vacuum by an intense electric field, we show that an electrostatic field can generate two coherent excitations from the superconducting ground-state condensate. Differently from the dissipative thermal excitation, these form a new macroscopically coherent and dissipationless state. We discuss how the superconducting state is weakened by the creation of this kind of excitations. In addition to shedding a different light and suggesting a method for the experimental verification of the Sauter-Schwinger effect, our results pave the way to the understanding and exploitation of the interaction between superconductors and electric fields.
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Affiliation(s)
- P Solinas
- Dipartimento di Fisica, Università di Genova, via Dodecaneso 33, I-16146 Genova, Italy
- INFN-Sezione di Genova, via Dodecaneso 33, I-16146 Genova, Italy
| | - A Amoretti
- Dipartimento di Fisica, Università di Genova, via Dodecaneso 33, I-16146 Genova, Italy
- INFN-Sezione di Genova, via Dodecaneso 33, I-16146 Genova, Italy
| | - F Giazotto
- NEST, Instituto Nanoscienze-CNR and Scuola Normale Superiore, I-56127 Pisa, Italy
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14
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Puglia C, De Simoni G, Giazotto F. Gate Control of Superconductivity in Mesoscopic All-Metallic Devices. MATERIALS (BASEL, SWITZERLAND) 2021; 14:1243. [PMID: 33807981 PMCID: PMC7961734 DOI: 10.3390/ma14051243] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Revised: 02/24/2021] [Accepted: 02/28/2021] [Indexed: 11/16/2022]
Abstract
The possibility to tune, through the application of a control gate voltage, the superconducting properties of mesoscopic devices based on Bardeen-Cooper-Schrieffer metals was recently demonstrated. Despite the extensive experimental evidence obtained on different materials and geometries, a description of the microscopic mechanism at the basis of such an unconventional effect has not been provided yet. This work discusses the technological potential of gate control of superconductivity in metallic superconductors and revises the experimental results, which provide information regarding a possible thermal origin of the effect: first, we review experiments performed on high-critical-temperature elemental superconductors (niobium and vanadium) and show how devices based on these materials can be exploited to realize basic electronic tools, such as a half-wave rectifier. Second, we discuss the origin of the gating effect by showing gate-driven suppression of the supercurrent in a suspended titanium wire and by providing a comparison between thermal and electric switching current probability distributions. Furthermore, we discuss the cold field-emission of electrons from the gate employing finite element simulations and compare the results with experimental data. In our view, the presented data provide a strong indication regarding the unlikelihood of the thermal origin of the gating effect.
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Affiliation(s)
- Claudio Puglia
- Department of Physics, University of Pisa, Largo Pontecorvo 3, I-56127 Pisa, Italy
- NEST, Instituto Nanoscienze-CNR and Scuola Normale Superiore, I-56127 Pisa, Italy; (G.D.S.); (F.G.)
| | - Giorgio De Simoni
- NEST, Instituto Nanoscienze-CNR and Scuola Normale Superiore, I-56127 Pisa, Italy; (G.D.S.); (F.G.)
| | - Francesco Giazotto
- NEST, Instituto Nanoscienze-CNR and Scuola Normale Superiore, I-56127 Pisa, Italy; (G.D.S.); (F.G.)
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15
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Rocci M, Suri D, Kamra A, Takamura Y, Nemes NM, Martinez JL, Hernandez MG, Moodera JS. Large Enhancement of Critical Current in Superconducting Devices by Gate Voltage. NANO LETTERS 2021; 21:216-221. [PMID: 33275436 DOI: 10.1021/acs.nanolett.0c03547] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Significant control over the properties of a high-carrier density superconductor via an applied electric field has been considered infeasible due to screening of the field over atomic length scales. Here, we demonstrate an enhancement of up to 30% in critical current in a back-gate tunable NbN micro- and nano superconducting bridges. Our suggested plausible mechanism of this enhancement in critical current based on surface nucleation and pinning of Abrikosov vortices is consistent with expectations and observations for type-II superconductor films with thicknesses comparable to their coherence length. Furthermore, we demonstrate an applied electric field-dependent infinite electroresistance and hysteretic resistance. Our work presents an electric field driven enhancement in the superconducting property in type-II superconductors which is a crucial step toward the understanding of field-effects on the fundamental properties of a superconductor and its exploitation for logic and memory applications in a superconductor-based low-dissipation digital computing paradigm.
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Affiliation(s)
- Mirko Rocci
- Francis Bitter Magnet Laboratory and Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
- NEST, Instituto Nanoscienze-CNR and Scuola Normale Superiore, I-56127 Pisa, Italy
| | - Dhavala Suri
- Francis Bitter Magnet Laboratory and Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Akashdeep Kamra
- Center for Quantum Spintronics, Department of Physics, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway
| | - Yota Takamura
- School of Engineering, Tokyo Institute of Technology, Tokyo 152-8550, Japan
| | - Norbert M Nemes
- GFMC, Departamento de Física de Materiales, Universidad Complutense de Madrid, E-28040 Madrid, Spain
| | - Jose L Martinez
- Instituto de Ciencia de Materiales de Madrid, C.S.I.C., Cantoblanco, E-28049 Madrid, Spain
| | - Mar Garcia Hernandez
- Instituto de Ciencia de Materiales de Madrid, C.S.I.C., Cantoblanco, E-28049 Madrid, Spain
| | - Jagadeesh S Moodera
- Francis Bitter Magnet Laboratory and Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
- Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
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16
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Rocci M, De Simoni G, Puglia C, Esposti DD, Strambini E, Zannier V, Sorba L, Giazotto F. Gate-Controlled Suspended Titanium Nanobridge Supercurrent Transistor. ACS NANO 2020; 14:12621-12628. [PMID: 32822153 DOI: 10.1021/acsnano.0c05355] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Under standard conditions, the electrostatic field-effect is negligible in conventional metals and was expected to be completely ineffective also in superconducting metals. This common belief was recently put under question by a family of experiments that displayed full gate-voltage-induced suppression of critical current in superconducting all-metallic gated nanotransistors. To date, the microscopic origin of this phenomenon is under debate, and trivial explanations based on heating effects given by the negligible electron leakage from the gates should be excluded. Here, we demonstrate the control of the supercurrent in fully suspended superconducting nanobridges. Our advanced nanofabrication methods allow us to build suspended superconducting Ti-based supercurrent transistors which show ambipolar and monotonic full suppression of the critical current for gate voltages of VGC ≃ 18 V and for temperatures up to ∼80% of the critical temperature. The suspended device architecture minimizes the electron-phonon interaction between the superconducting nanobridge and the substrate, and therefore, it rules out any possible contribution stemming from charge injection into the insulating substrate. Besides, our finite element method simulations of vacuum electron tunneling from the gate to the bridge and thermal considerations rule out the cold-electron field emission as a possible driving mechanism for the observed phenomenology. Our findings promise a better understanding of the field effect in superconducting metals.
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Affiliation(s)
- Mirko Rocci
- NEST, Istituto Nanoscienze-CNR and Scuola Normale Superiore, I-56127 Pisa, Italy
| | - Giorgio De Simoni
- NEST, Istituto Nanoscienze-CNR and Scuola Normale Superiore, I-56127 Pisa, Italy
| | - Claudio Puglia
- NEST, Istituto Nanoscienze-CNR and Scuola Normale Superiore, I-56127 Pisa, Italy
- Department of Physics "E. Fermi", Università di Pisa, Largo Pontecorvo 3, I-56127 Pisa, Italy
| | - Davide Degli Esposti
- NEST, Istituto Nanoscienze-CNR and Scuola Normale Superiore, I-56127 Pisa, Italy
- Department of Physics "E. Fermi", Università di Pisa, Largo Pontecorvo 3, I-56127 Pisa, Italy
| | - Elia Strambini
- NEST, Istituto Nanoscienze-CNR and Scuola Normale Superiore, I-56127 Pisa, Italy
| | - Valentina Zannier
- NEST, Istituto Nanoscienze-CNR and Scuola Normale Superiore, I-56127 Pisa, Italy
| | - Lucia Sorba
- NEST, Istituto Nanoscienze-CNR and Scuola Normale Superiore, I-56127 Pisa, Italy
| | - Francesco Giazotto
- NEST, Istituto Nanoscienze-CNR and Scuola Normale Superiore, I-56127 Pisa, Italy
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17
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Paolucci F, Vischi F, De Simoni G, Guarcello C, Solinas P, Giazotto F. Field-Effect Controllable Metallic Josephson Interferometer. NANO LETTERS 2019; 19:6263-6269. [PMID: 31461290 DOI: 10.1021/acs.nanolett.9b02369] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Gate-tunable Josephson junctions (JJs) are the backbone of superconducting classical and quantum computation. Typically, these systems exploit low-charge-concentration materials and present technological difficulties limiting their scalability. Surprisingly, electric field modulation of a supercurrent in metallic wires and JJs has been recently demonstrated. Here, we report the realization of titanium-based monolithic interferometers which allow tuning both JJs independently via voltage bias applied to capacitively coupled electrodes. Our experiments demonstrate full control of the amplitude of the switching current (Is) and of the superconducting phase across the single JJ in a wide range of temperatures. Astoundingly, by gate-biasing a single junction, the maximum achievable total Is is suppressed down to values much lower than the critical current of a single JJ. A theoretical model including gate-induced phase fluctuations on a single junction accounts for our experimental findings. This class of quantum interferometers could represent a breakthrough for several applications such as digital electronics, quantum computing, sensitive magnetometry, and single-photon detection.
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Affiliation(s)
- Federico Paolucci
- INFN Sezione di Pisa , Largo Bruno Pontecorvo 3 , I-56127 Pisa , Italy
- NEST , Instituto Nanoscienze-CNR and Scuola Normale Superiore , I-56127 Pisa , Italy
| | - Francesco Vischi
- NEST , Instituto Nanoscienze-CNR and Scuola Normale Superiore , I-56127 Pisa , Italy
- Dipartimento di Fisica , Università di Pisa , Largo Pontecorvo 3 , I-56127 Pisa , Italy
| | - Giorgio De Simoni
- NEST , Instituto Nanoscienze-CNR and Scuola Normale Superiore , I-56127 Pisa , Italy
| | - Claudio Guarcello
- 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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18
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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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