1
|
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.
Collapse
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
| |
Collapse
|
2
|
Jonckheere T, Rech J, Zazunov A, Egger R, Yeyati AL, Martin T. Giant Shot Noise from Majorana Zero Modes in Topological Trijunctions. PHYSICAL REVIEW LETTERS 2019; 122:097003. [PMID: 30932546 DOI: 10.1103/physrevlett.122.097003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Indexed: 06/09/2023]
Abstract
The clear-cut experimental identification of Majorana bound states in transport measurements still poses experimental challenges. We here show that the zero-energy Majorana state formed at a junction of three topological superconductor wires is directly responsible for giant shot noise amplitudes, in particular at low voltages and for small contact transparency. The only intrinsic noise limitation comes from the current-induced dephasing rate due to multiple Andreev reflection processes.
Collapse
Affiliation(s)
- T Jonckheere
- Aix Marseille Univ, Université de Toulon, CNRS, CPT, Marseille, France
| | - J Rech
- Aix Marseille Univ, Université de Toulon, CNRS, CPT, Marseille, France
| | - A Zazunov
- Institut für Theoretische Physik, Heinrich Heine Universität, D-40225 Düsseldorf, Germany
| | - R Egger
- Institut für Theoretische Physik, Heinrich Heine Universität, D-40225 Düsseldorf, Germany
| | - A Levy Yeyati
- Departamento de Física Teórica de la Materia Condensada C-V, Condensed Matter Physics Center (IFIMAC) and Instituto Nicolás Cabrera, Universidad Autónoma de Madrid, E-28049 Madrid, Spain
| | - T Martin
- Aix Marseille Univ, Université de Toulon, CNRS, CPT, Marseille, France
| |
Collapse
|
3
|
Murani A, Dassonneville B, Kasumov A, Basset J, Ferrier M, Deblock R, Guéron S, Bouchiat H. Microwave Signature of Topological Andreev level Crossings in a Bismuth-based Josephson Junction. PHYSICAL REVIEW LETTERS 2019; 122:076802. [PMID: 30848609 DOI: 10.1103/physrevlett.122.076802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Indexed: 06/09/2023]
Abstract
Demonstrating the topological protection of Andreev states in Josephson junctions is an experimental challenge. In particular the telltale 4π periodicity expected for the current phase relation has remained elusive, because of fast parity breaking processes. It was predicted that low temperature ac susceptibility measurements could reveal the topological protection of quantum spin Hall edge states by probing their low energy Andreev spectrum at finite frequency. We have performed such a microwave probing of a phase-biased Josephson junction built around a bismuth nanowire, a predicted second order topological insulator, and which was previously shown to host one-dimensional ballistic edge states. We find absorption peaks at the Andreev level crossings, whose temperature and frequency dependencies point to protected topological crossings with an accuracy limited by the electronic temperature of our experiment.
Collapse
Affiliation(s)
- A Murani
- Laboratoire de Physique des Solides, CNRS, Université Paris-Sud, Université Paris-Saclay, 91405 Orsay Cedex, France
- Quantronics Group, Service de Physique de l'État Condensé (CNRS UMR 3680), IRAMIS, CEA-Saclay, 91191 Gif-sur-Yvette, France
| | - B Dassonneville
- Laboratoire de Physique des Solides, CNRS, Université Paris-Sud, Université Paris-Saclay, 91405 Orsay Cedex, France
| | - A Kasumov
- Laboratoire de Physique des Solides, CNRS, Université Paris-Sud, Université Paris-Saclay, 91405 Orsay Cedex, France
| | - J Basset
- Laboratoire de Physique des Solides, CNRS, Université Paris-Sud, Université Paris-Saclay, 91405 Orsay Cedex, France
| | - M Ferrier
- Laboratoire de Physique des Solides, CNRS, Université Paris-Sud, Université Paris-Saclay, 91405 Orsay Cedex, France
| | - R Deblock
- Laboratoire de Physique des Solides, CNRS, Université Paris-Sud, Université Paris-Saclay, 91405 Orsay Cedex, France
| | - S Guéron
- Laboratoire de Physique des Solides, CNRS, Université Paris-Sud, Université Paris-Saclay, 91405 Orsay Cedex, France
| | - H Bouchiat
- Laboratoire de Physique des Solides, CNRS, Université Paris-Sud, Université Paris-Saclay, 91405 Orsay Cedex, France
| |
Collapse
|
4
|
Hata T, Delagrange R, Arakawa T, Lee S, Deblock R, Bouchiat H, Kobayashi K, Ferrier M. Enhanced Shot Noise of Multiple Andreev Reflections in a Carbon Nanotube Quantum Dot in SU(2) and SU(4) Kondo regimes. PHYSICAL REVIEW LETTERS 2018; 121:247703. [PMID: 30608725 DOI: 10.1103/physrevlett.121.247703] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Indexed: 06/09/2023]
Abstract
The sensitivity of shot noise to the interplay between Kondo correlations and superconductivity is investigated in a carbon nanotube quantum dot connected to superconducting electrodes. Depending on the gate voltage, the SU(2) and SU(4) Kondo unitary regimes can be clearly identified. We observe enhancement of the shot noise via the Fano factor in the superconducting state. Its divergence at low bias voltage, which is more pronounced in the SU(4) regime than in the SU(2) one, is larger than what is expected from proliferation of multiple Andreev reflections predicted by the existing theories. Our result suggests that the Kondo effect is responsible for this strong enhancement.
Collapse
Affiliation(s)
- Tokuro Hata
- Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Raphaëlle Delagrange
- Laboratoire de Physique des Solides, CNRS, Univ. Paris-sud, Université Paris-Saclay, 91405 Orsay Cedex, France
| | - Tomonori Arakawa
- Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
- Center for Spintronics Research Network, Osaka University, Toyonaka, Osaka 560-8531, Japan
| | - Sanghyun Lee
- Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Richard Deblock
- Laboratoire de Physique des Solides, CNRS, Univ. Paris-sud, Université Paris-Saclay, 91405 Orsay Cedex, France
| | - Hélène Bouchiat
- Laboratoire de Physique des Solides, CNRS, Univ. Paris-sud, Université Paris-Saclay, 91405 Orsay Cedex, France
| | - Kensuke Kobayashi
- Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
- Center for Spintronics Research Network, Osaka University, Toyonaka, Osaka 560-8531, Japan
- Quantum Information and Quantum Biology Division, Institute for Open and Transdisciplinary Research Initiatives, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Meydi Ferrier
- Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
- Laboratoire de Physique des Solides, CNRS, Univ. Paris-sud, Université Paris-Saclay, 91405 Orsay Cedex, France
| |
Collapse
|
5
|
Nonlocal supercurrent of quartets in a three-terminal Josephson junction. Proc Natl Acad Sci U S A 2018; 115:6991-6994. [PMID: 29915041 DOI: 10.1073/pnas.1800044115] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A novel nonlocal supercurrent, carried by quartets, each consisting of four electrons, is expected to appear in a voltage-biased three-terminal Josephson junction. This supercurrent results from a nonlocal Andreev bound state (ABS), formed among three superconducting terminals. While in a two-terminal Josephson junction the usual ABS, and thus the dc Josephson current, exists only in equilibrium, the ABS, which gives rise to the quartet supercurrent, persists in the nonlinear regime. In this work, we report such resonance in a highly coherent three-terminal Josephson junction made in an InAs nanowire in proximity to an aluminum superconductor. In addition to nonlocal conductance measurements, cross-correlation measurements of current fluctuations provided a distinctive signature of the quartet supercurrent. Multiple device geometries had been tested, allowing us to rule out competing mechanisms and to establish the underlying microscopic origin of this coherent nondissipative current.
Collapse
|
6
|
Dassonneville B, Ferrier M, Guéron S, Bouchiat H. Dissipation and supercurrent fluctuations in a diffusive normal-metal-superconductor ring. PHYSICAL REVIEW LETTERS 2013; 110:217001. [PMID: 23745912 DOI: 10.1103/physrevlett.110.217001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2013] [Indexed: 06/02/2023]
Abstract
A mesoscopic hybrid normal-metal-superconductor ring is characterized by a dense Andreev spectrum with a flux dependent minigap. To probe the dynamics of such a ring, we measure its linear response to a high frequency flux, in a wide frequency range, with a multimode superconducting resonator. We find that the current response contains, besides the well-known dissipationless Josephson contribution, a large dissipative component. At high frequency compared to the minigap and low temperature, we find that the dissipation is due to transitions across the minigap. In contrast, at lower frequency there is a range of temperature for which dissipation is caused predominantly by the relaxation of the Andreev states' population. This dissipative response, related via the fluctuation dissipation theorem to a nonintuitive zero frequency thermal noise of supercurrent, is characterized by a phase dependence dominated by its second harmonic, as predicted long ago but never observed thus far.
Collapse
Affiliation(s)
- B Dassonneville
- LPS, University of Paris-Sud, CNRS, UMR 8502, F-91405 Orsay Cedex, France
| | | | | | | |
Collapse
|
7
|
Freyn A, Douçot B, Feinberg D, Mélin R. Production of nonlocal quartets and phase-sensitive entanglement in a superconducting beam splitter. PHYSICAL REVIEW LETTERS 2011; 106:257005. [PMID: 21770667 DOI: 10.1103/physrevlett.106.257005] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2011] [Indexed: 05/31/2023]
Abstract
Three BCS superconductors Sa, Sb, and S and two short normal regions Na and Nb in a three-terminal SaNaSNb Sb setup provide a source of nonlocal quartets spatially separated as two correlated pairs in Sa and Sb, if the distance between the interfaces Na S and SNb is comparable to the coherence length in S. Low-temperature dc transport of nonlocal quartets from S to Sa and Sb can occur in equilibrium, and also if Sa and Sb are biased at opposite voltages. At higher temperatures, thermal excitations result in correlated current fluctuations which depend on the superconducting phases Φa and Φb in Sa and Sb. Phase-sensitive entanglement is obtained at zero temperature if Na and Nb are replaced by discrete levels.
Collapse
Affiliation(s)
- Axel Freyn
- Institut NEEL, CNRS, and Université Joseph Fourier, BP 166, F-38042 Grenoble Cedex 9, France
| | | | | | | |
Collapse
|
8
|
Semenov AG, Zaikin AD. Fluctuations of persistent current. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2010; 22:485302. [PMID: 21406742 DOI: 10.1088/0953-8984/22/48/485302] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We theoretically analyze equilibrium fluctuations of the persistent current (PC) in nanorings. We demonstrate that these fluctuations persist down to zero temperature provided the current operator does not commute with the total Hamiltonian of the system. For a model of a quantum particle on a ring we explicitly evaluate PC noise power which has the form of sharp peaks at frequencies set by the corresponding interlevel distances. In rings with many conducting channels, a much smoother and broader PC noise spectrum is expected. A specific feature of PC noise is that its spectrum can be tuned by an external magnetic flux indicating the presence of quantum coherence in the system.
Collapse
Affiliation(s)
- A G Semenov
- I E Tamm Department of Theoretical Physics, P N Lebedev Physics Institute, Moscow, Russia.
| | | |
Collapse
|
9
|
Uzawa Y, Wang Z. Coherent multiple charge transfer in a superconducting NbN tunnel junction. PHYSICAL REVIEW LETTERS 2005; 95:017002. [PMID: 16090645 DOI: 10.1103/physrevlett.95.017002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2004] [Indexed: 05/03/2023]
Abstract
We measured shot noise and submillimeter-wave response in a superconducting NbN tunnel junction that had a subharmonic gap structure on the current-voltage (I-V) curve. We found that the observed effective charge, defined from the noise-current ratio, tends to a steplike function of voltage. In the presence of submillimeter-wave radiation of frequency v, novel step structures spaced by hv/2e below and above the half-gap voltage clearly appeared on the I-V curve, overlapping the ordinary photon-assisted tunneling steps spaced by hv/e. Observation of these features provides clear evidence that coherent multiple Andreev reflection processes occur in the NbN tunnel junction with low barrier transparency.
Collapse
Affiliation(s)
- Y Uzawa
- Kansai Advanced Research Center, National Institute of Information and Communications Technology, 588-2 Iwaoka, Iwaoka-cho, Nishi-ku, Kobe 651-2492, Japan
| | | |
Collapse
|
10
|
Pilgram S, Samuelsson P. Noise and full counting statistics of incoherent multiple Andreev reflection. PHYSICAL REVIEW LETTERS 2005; 94:086806. [PMID: 15783919 DOI: 10.1103/physrevlett.94.086806] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2004] [Indexed: 05/24/2023]
Abstract
We present a general theory for the full counting statistics of multiple Andreev reflections in incoherent superconducting-normal-superconducting contacts. The theory, based on a stochastic path integral approach, is applied to a superconductor-double-barrier system. It is found that all cumulants of the current show a pronounced subharmonic gap structure at voltages V=2Delta/en. For low voltages V<<Delta/e, the counting statistics results from diffusion of multiple charges in energy space, giving the pth cumulant Q(p) proportional, variantV(2-p), diverging for p> or =3. We show that this low-voltage result holds for a large class of incoherent superconducting-normal-superconducting contacts.
Collapse
Affiliation(s)
- S Pilgram
- Département de Physique Théorique, Universitè de Genéve, CH-1211, Genève 4, Switzerland
| | | |
Collapse
|
11
|
Course 5 Noise in mesoscopic physics. NANOPHYSICS: COHERENCE AND TRANSPORT, ÉCOLE D'ÉTÉ DE PHYSIQUE DES HOUCHES SESSION LXXXI 2005. [DOI: 10.1016/s0924-8099(05)80047-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
|
12
|
Johansson G, Samuelsson P, Ingerman A. Full counting statistics of multiple Andreev reflection. PHYSICAL REVIEW LETTERS 2003; 91:187002. [PMID: 14611307 DOI: 10.1103/physrevlett.91.187002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2003] [Indexed: 05/24/2023]
Abstract
We derive the full counting statistics of charge transfer through a voltage biased superconducting junction. We find that, for measurement times much longer than the inverse Josephson frequency, the counting statistics describes a correlated transfer of quanta of multiple electron charges, each quantum associated with the transfer of a single quasiparticle. An expression for the counting statistics in terms of the quasiparticle scattering amplitudes is derived.
Collapse
Affiliation(s)
- Göran Johansson
- Institut für Theoretische Festkörperphysik, Universität Karlsruhe, D-76128 Karlsruhe, Germany
| | | | | |
Collapse
|
13
|
Belzig W, Nazarov YV. Full counting statistics of electron transfer between superconductors. PHYSICAL REVIEW LETTERS 2001; 87:197006. [PMID: 11690449 DOI: 10.1103/physrevlett.87.197006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2000] [Indexed: 05/23/2023]
Abstract
We present an extension of the Keldysh-Green's function method, which allows one to calculate the full distribution of transmitted particles through a mesoscopic superconductor. The method is applied to the statistics of supercurrent in short contacts. If the current is carried by Andreev bound states the distribution corresponds to switching between long trains of electrons going in opposite directions. For weak (gapless) superconductors or tunnel junctions we find that at low temperatures the distribution has negative "probabilities." Accounting for the quantum mechanical nature of the measuring device shows that these negative values can indeed be measured.
Collapse
Affiliation(s)
- W Belzig
- Department of Applied Physics and Delft Institute of Microelectronics and Submicrontechnology, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands
| | | |
Collapse
|
14
|
Choi MS, Plastina F, Fazio R. Shot noise for resonant Cooper pair tunneling. PHYSICAL REVIEW LETTERS 2001; 87:116601. [PMID: 11531539 DOI: 10.1103/physrevlett.87.116601] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2001] [Indexed: 05/23/2023]
Abstract
We study intrinsic noise of current in a superconducting single-electron transistor, taking into account both coherence effects and Coulomb interaction near a Cooper pair resonance. Because of this interplay, the statistics of tunneling events deviates from the Poisson distribution and, more important, it shows even-odd asymmetry in the transmitted charge. The zero-frequency noise is suppressed significantly when the quasiparticle tunneling rates are comparable to the coherent oscillation frequency of Cooper pairs.
Collapse
Affiliation(s)
- M S Choi
- Department of Physics and Astronomy, University of Basel, Klingelberstrasse 82, 4056 Basel, Switzerland
| | | | | |
Collapse
|
15
|
Cron R, Goffman MF, Esteve D, Urbina C. Multiple-charge-quanta shot noise in superconducting atomic contacts. PHYSICAL REVIEW LETTERS 2001; 86:4104-4107. [PMID: 11328106 DOI: 10.1103/physrevlett.86.4104] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2000] [Indexed: 05/23/2023]
Abstract
We have measured shot noise in aluminum atomic point contacts containing a small number of conduction channels of known transmissions. In the normal state, we find that the noise power is reduced from its Poissonian value and reaches the partition limit, as calculated from the transmissions. In the superconducting state, the noise reveals the large effective charge associated with each elementary transfer process, in excellent agreement with the predictions of the quantum theory of multiple Andreev reflections.
Collapse
Affiliation(s)
- R Cron
- Service de Physique de l'Etat Condensé, Commissariat à l'Energie Atomique, Saclay, F-91191 Gif-sur-Yvette Cedex, France
| | | | | | | |
Collapse
|
16
|
Nagaev KE. Frequency-dependent shot noise in long disordered superconductor-normal-metal-superconductor contacts. PHYSICAL REVIEW LETTERS 2001; 86:3112-3115. [PMID: 11290120 DOI: 10.1103/physrevlett.86.3112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2000] [Indexed: 05/23/2023]
Abstract
The shot noise in long diffusive superconductor-normal-metal-superconductor contacts is calculated using the semiclassical approach. At low frequencies and for purely elastic scattering, the voltage dependence of the noise is of the form S(I) = (4Delta+2eV)/3R. The electron-electron scattering suppresses the noise at small voltages resulting in vanishing noise yet infinite dS(I)/dV at V = 0. The distribution function of electrons consists of a series of steps, and the frequency dependence of noise exhibits peculiarities at omega = neV, omega = neV-2Delta, and omega = 2Delta-neV for integer n.
Collapse
Affiliation(s)
- K E Nagaev
- Institute of Radioengineering and Electronics, Russian Academy of Sciences, Mokhovaya ulica 11, 103907 Moscow, Russia
| |
Collapse
|