1
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Liang YX. Ultra-low-noise transimpedance amplifier with a single HEMT in pre-amplifier for measuring shot noise in cryogenic STM. Ultramicroscopy 2024; 267:114051. [PMID: 39341012 DOI: 10.1016/j.ultramic.2024.114051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Revised: 08/16/2024] [Accepted: 09/13/2024] [Indexed: 09/30/2024]
Abstract
In this work, a design of transimpedance amplifier (TIA) for cryogenic scanning tunneling microscope (CryoSTM) is proposed. TIA with the tip-sample component in CryoSTM is called as CryoSTM-TIA. With transimpedance gain of 1 GΩ, the bandwidth of the CryoSTM-TIA is larger than 200 kHz. The distinctive feature of the proposed CryoSTM-TIA is that its pre-amplifier is made of a single cryogenic high electron mobility transistor (HEMT), so the apparatus equivalent input noise current power spectral density at 100 kHz is lower than 6 (fA)2/Hz. In addition, "bias-cooling method" can be used to in-situ control the density of the frozen DX- centers in the HEMT doping area, changing its structure to reduce the device noises. With this apparatus, fast scanning tunneling spectra measurements with high-energy-resolution are capable to be performed. And, it is capable to measure scanning tunneling shot noise spectra (STSNS) at the atomic scale for various quantum systems, even if the shot noise is very low. It provides a powerful tool to investigate novel quantum states by measuring STSNS, such as detecting the existence of Majorana bound states in the topological quantum systems.
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Affiliation(s)
- Ying-Xin Liang
- Beijing Academy of Quantum Information Sciences, Haidian 100193, Beijing, China; Coll Phys & Elect Engn, Anyang Normal University, Anyang, 455000, Henan, China.
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2
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Bi J, Lin Y, Zhang Q, Liu Z, Zhang Z, Zhang R, Yao X, Chen G, Liu H, Huang Y, Sun Y, Zhang H, Sun Z, Xiao S, Cao Y. Momentum-Resolved Electronic Structures and Strong Electronic Correlations in Graphene-like Nitride Superconductors. NANO LETTERS 2024. [PMID: 38781119 DOI: 10.1021/acs.nanolett.4c01704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2024]
Abstract
Although transition-metal nitrides have been widely applied for several decades, experimental investigations of their high-resolution electronic band structures are rare due to the lack of high-quality single-crystalline samples. Here, we report on the first momentum-resolved electronic band structures of titanium nitride (TiN) films, which are remarkable nitride superconductors. The measurements of the crystal structures and electrical transport properties confirmed the high quality of these films. More importantly, from a combination of high-resolution angle-resolved photoelectron spectroscopy and first-principles calculations, the extracted Coulomb interaction strength of TiN films can be as large as 8.5 eV, whereas resonant photoemission spectroscopy yields a value of 6.26 eV. These large values of Coulomb interaction strength indicate that superconducting TiN is a strongly correlated system. Our results uncover the unexpected electronic correlations in transition-metal nitrides, potentially providing a perspective not only to understand their emergent quantum states but also to develop their applications in quantum devices.
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Affiliation(s)
- Jiachang Bi
- Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, People's Republic of China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Yu Lin
- Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, People's Republic of China
- Yongjiang laboratory, Ningbo, Zhejiang 315202, People's Republic of China
| | - Qinghua Zhang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
| | - Zhanfeng Liu
- National Synchrotron Radiation Laboratory, CAS Center for Excellence in Nanoscience, University of Science and Technology of China, Hefei 230029, People's Republic of China
| | - Ziyun Zhang
- School of Physical Science and Technology, Shanghai Tech University, Shanghai 201210, People's Republic of China
| | - Ruyi Zhang
- Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, People's Republic of China
| | - Xiong Yao
- Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, People's Republic of China
| | - Guoxin Chen
- Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, People's Republic of China
| | - Haigang Liu
- Shanghai Synchrotron Radiation Facility (SSRF), Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201204, People's Republic of China
| | - Yaobo Huang
- Shanghai Synchrotron Radiation Facility (SSRF), Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201204, People's Republic of China
| | - Yuanhe Sun
- Shanghai Synchrotron Radiation Facility (SSRF), Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201204, People's Republic of China
- Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, People's Republic of China
| | - Hui Zhang
- Shanghai Synchrotron Radiation Facility (SSRF), Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201204, People's Republic of China
| | - Zhe Sun
- National Synchrotron Radiation Laboratory, CAS Center for Excellence in Nanoscience, University of Science and Technology of China, Hefei 230029, People's Republic of China
| | - Shaozhu Xiao
- Yongjiang laboratory, Ningbo, Zhejiang 315202, People's Republic of China
| | - Yanwei Cao
- Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, People's Republic of China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
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3
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Niu J, Bastiaans KM, Ge JF, Tomar R, Jesudasan J, Raychaudhuri P, Karrer M, Kleiner R, Koelle D, Barbier A, Driessen EFC, Blanter YM, Allan MP. Why Shot Noise Does Not Generally Detect Pairing in Mesoscopic Superconducting Tunnel Junctions. PHYSICAL REVIEW LETTERS 2024; 132:076001. [PMID: 38427861 DOI: 10.1103/physrevlett.132.076001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Revised: 10/13/2023] [Accepted: 12/01/2023] [Indexed: 03/03/2024]
Abstract
The shot noise in tunneling experiments reflects the Poissonian nature of the tunneling process. The shot-noise power is proportional to both the magnitude of the current and the effective charge of the carrier. Shot-noise spectroscopy thus enables us, in principle, to determine the effective charge q of the charge carriers of that tunnel. This can be used to detect electron pairing in superconductors: In the normal state, the noise corresponds to single electron tunneling (q=1e), while in the paired state, the noise corresponds to q=2e. Here, we use a newly developed amplifier to reveal that in typical mesoscopic superconducting junctions, the shot noise does not reflect the signatures of pairing and instead stays at a level corresponding to q=1e. We show that transparency can control the shot noise, and this q=1e is due to the large number of tunneling channels with each having very low transparency. Our results indicate that in typical mesoscopic superconducting junctions, one should expect q=1e noise and lead to design guidelines for junctions that allow the detection of electron pairing.
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Affiliation(s)
- Jiasen Niu
- Leiden Institute of Physics, Leiden University, 2333 CA Leiden, The Netherlands
| | - Koen M Bastiaans
- Department of Quantum Nanoscience, Kavli Institute of Nanoscience, Delft University of Technology, 2628 CJ Delft, The Netherlands
| | - Jian-Feng Ge
- Leiden Institute of Physics, Leiden University, 2333 CA Leiden, The Netherlands
| | - Ruchi Tomar
- Department of Condensed Matter Physics and Materials Science, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai 400005, India
| | - John Jesudasan
- Department of Condensed Matter Physics and Materials Science, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai 400005, India
| | - Pratap Raychaudhuri
- Department of Condensed Matter Physics and Materials Science, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai 400005, India
| | - Max Karrer
- Physikalisches Institut, Center for Quantum Science (CQ) and LISA+, Universität Tübingen, D-72076 Tübingen, Germany
| | - Reinhold Kleiner
- Physikalisches Institut, Center for Quantum Science (CQ) and LISA+, Universität Tübingen, D-72076 Tübingen, Germany
| | - Dieter Koelle
- Physikalisches Institut, Center for Quantum Science (CQ) and LISA+, Universität Tübingen, D-72076 Tübingen, Germany
| | - Arnaud Barbier
- Institut de Radioastronomie Millimétrique (IRAM), Domaine Universitaire de Grenoble, 38400 Saint-Martin-d'Hères, France
| | - Eduard F C Driessen
- Institut de Radioastronomie Millimétrique (IRAM), Domaine Universitaire de Grenoble, 38400 Saint-Martin-d'Hères, France
| | - Yaroslav M Blanter
- Department of Quantum Nanoscience, Kavli Institute of Nanoscience, Delft University of Technology, 2628 CJ Delft, The Netherlands
| | - Milan P Allan
- Leiden Institute of Physics, Leiden University, 2333 CA Leiden, The Netherlands
- Fakultät für Physik, Ludwig-Maximilians-Universität, Schellingstrasse 4, München 80799, Germany
- Munich Center for Quantum Science and Technology (MCQST), München, Germany
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4
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Chen L, Lowder DT, Bakali E, Andrews AM, Schrenk W, Waas M, Svagera R, Eguchi G, Prochaska L, Wang Y, Setty C, Sur S, Si Q, Paschen S, Natelson D. Shot noise in a strange metal. Science 2023; 382:907-911. [PMID: 37995251 DOI: 10.1126/science.abq6100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Accepted: 10/12/2023] [Indexed: 11/25/2023]
Abstract
Strange-metal behavior has been observed in materials ranging from high-temperature superconductors to heavy fermion metals. In conventional metals, current is carried by quasiparticles; although it has been suggested that quasiparticles are absent in strange metals, direct experimental evidence is lacking. We measured shot noise to probe the granularity of the current-carrying excitations in nanowires of the heavy fermion strange metal YbRh2Si2. When compared with conventional metals, shot noise in these nanowires is strongly suppressed. This suppression cannot be attributed to either electron-phonon or electron-electron interactions in a Fermi liquid, which suggests that the current is not carried by well-defined quasiparticles in the strange-metal regime that we probed. Our work sets the stage for similar studies of other strange metals.
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Affiliation(s)
- Liyang Chen
- Applied Physics Graduate Program, Rice University, TX 77005, USA
| | - Dale T Lowder
- Department of Physics and Astronomy, Rice Center for Quantum Materials, Rice University, Houston, TX 77005, USA
| | - Emine Bakali
- Institute of Solid State Physics, TU Wien, Wiedner Hauptstraße 8-10, 1040 Vienna, Austria
| | - Aaron Maxwell Andrews
- Institute of Solid State Electronics, TU Wien, Gußhausstraße 25-25a, Gebäude CH, 1040 Vienna, Austria
| | - Werner Schrenk
- Center for Micro and Nanostructures, TU Wien, Gußhausstraße 25-25a, Gebäude CH, 1040 Vienna, Austria
| | - Monika Waas
- Institute of Solid State Physics, TU Wien, Wiedner Hauptstraße 8-10, 1040 Vienna, Austria
| | - Robert Svagera
- Institute of Solid State Physics, TU Wien, Wiedner Hauptstraße 8-10, 1040 Vienna, Austria
| | - Gaku Eguchi
- Institute of Solid State Physics, TU Wien, Wiedner Hauptstraße 8-10, 1040 Vienna, Austria
| | - Lukas Prochaska
- Institute of Solid State Physics, TU Wien, Wiedner Hauptstraße 8-10, 1040 Vienna, Austria
| | - Yiming Wang
- Department of Physics and Astronomy, Rice Center for Quantum Materials, Rice University, Houston, TX 77005, USA
| | - Chandan Setty
- Department of Physics and Astronomy, Rice Center for Quantum Materials, Rice University, Houston, TX 77005, USA
| | - Shouvik Sur
- Department of Physics and Astronomy, Rice Center for Quantum Materials, Rice University, Houston, TX 77005, USA
| | - Qimiao Si
- Department of Physics and Astronomy, Rice Center for Quantum Materials, Rice University, Houston, TX 77005, USA
| | - Silke Paschen
- Institute of Solid State Physics, TU Wien, Wiedner Hauptstraße 8-10, 1040 Vienna, Austria
| | - Douglas Natelson
- Department of Physics and Astronomy, Rice Center for Quantum Materials, Rice University, Houston, TX 77005, USA
- Department of Electrical and Computer Engineering, Rice University, Houston, TX 77005, USA
- Department of Materials Science and NanoEngineering, Rice University, Houston, TX 77005, USA
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5
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Siebrecht J, Huang H, Kot P, Drost R, Padurariu C, Kubala B, Ankerhold J, Cuevas JC, Ast CR. Microwave excitation of atomic scale superconducting bound states. Nat Commun 2023; 14:6794. [PMID: 37880208 PMCID: PMC10600199 DOI: 10.1038/s41467-023-42454-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Accepted: 10/11/2023] [Indexed: 10/27/2023] Open
Abstract
Magnetic impurities on superconductors lead to bound states within the superconducting gap, so called Yu-Shiba-Rusinov (YSR) states. They are parity protected, which enhances their lifetime, but makes it more difficult to excite them. Here, we realize the excitation of YSR states by microwaves facilitated by the tunnel coupling to another superconducting electrode in a scanning tunneling microscope (STM). We identify the excitation process through a family of anomalous microwave-assisted tunneling peaks originating from a second-order resonant Andreev process, in which the microwave excites the YSR state triggering a tunneling event transferring a total of two charges. We vary the amplitude and the frequency of the microwave to identify the energy threshold and the evolution of this excitation process. Our work sets an experimental basis and proof-of-principle for the manipulation of YSR states using microwaves with an outlook towards YSR qubits.
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Affiliation(s)
- Janis Siebrecht
- Max-Planck-Institut für Festkörperforschung, Heisenbergstraße 1, 70569, Stuttgart, Germany
| | - Haonan Huang
- Max-Planck-Institut für Festkörperforschung, Heisenbergstraße 1, 70569, Stuttgart, Germany
| | - Piotr Kot
- Max-Planck-Institut für Festkörperforschung, Heisenbergstraße 1, 70569, Stuttgart, Germany
| | - Robert Drost
- Max-Planck-Institut für Festkörperforschung, Heisenbergstraße 1, 70569, Stuttgart, Germany
| | - Ciprian Padurariu
- Institut für Komplexe Quantensysteme and IQST, Universität Ulm, Albert-Einstein-Allee 11, 89069, Ulm, Germany
| | - Björn Kubala
- Institut für Komplexe Quantensysteme and IQST, Universität Ulm, Albert-Einstein-Allee 11, 89069, Ulm, Germany
- Institute for Quantum Technologies, German Aerospace Center (DLR), Wilhelm-Runge Straße 10, 89081, Ulm, Germany
| | - Joachim Ankerhold
- Institut für Komplexe Quantensysteme and IQST, Universität Ulm, Albert-Einstein-Allee 11, 89069, Ulm, Germany
| | - Juan Carlos Cuevas
- Departamento de Física Teórica de la Materia Condensada and Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, 28049, Madrid, Spain
| | - Christian R Ast
- Max-Planck-Institut für Festkörperforschung, Heisenbergstraße 1, 70569, Stuttgart, Germany.
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6
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Takahashi K, Nakatsugawa K, Sakoda M, Nanao Y, Nobukane H, Obuse H, Tanda S. Bose glass and Fermi glass. Sci Rep 2023; 13:12434. [PMID: 37528223 PMCID: PMC10394042 DOI: 10.1038/s41598-023-39285-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2023] [Accepted: 07/22/2023] [Indexed: 08/03/2023] Open
Abstract
It is known that two-dimensional superconducting materials undergo a quantum phase transition from a localized state to superconductivity. When the disordered samples are cooled, bosons (Cooper pairs) are generated from Fermi glass and reach superconductivity through Bose glass. However, there has been no universal expression representing the transition from Fermi glass to Bose glass. Here, we discovered an experimental renormalization group flow from Fermi glass to Bose glass in terms of simple [Formula: see text]-function analysis. To discuss the universality of this flow, we analyzed manifestly different systems, namely a Nd-based two-dimensional layered perovskite and an ultrathin Pb film. We find that all our experimental data for Fermi glass fall beautifully into the conventional self-consistent [Formula: see text]-function. Surprisingly, however, flows perpendicular to the conventional [Formula: see text]-function are observed in the weakly localized regime of both systems, where localization becomes even weaker. Consequently, we propose a universal transition from Bose glass to Fermi glass with the new two-dimensional critical sheet resistance close to [Formula: see text].
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Affiliation(s)
- Korekiyo Takahashi
- Department of Applied Physics, Hokkaido University, Sapporo, 060-8628, Japan.
- Center of Education and Research for Topological Science and Technology, Hokkaido University, Sapporo, 060-8628, Japan.
- Nomura Research Institute, Ltd., Tokyo, 100-0004, Japan.
| | - Keiji Nakatsugawa
- Center of Education and Research for Topological Science and Technology, Hokkaido University, Sapporo, 060-8628, Japan
- Research Center for Materials Nanoarchitectonics, National Institute for Material Science, Tsukuba, 305-0044, Japan
| | - Masahito Sakoda
- Department of Applied Physics, Hokkaido University, Sapporo, 060-8628, Japan
- Center of Education and Research for Topological Science and Technology, Hokkaido University, Sapporo, 060-8628, Japan
| | - Yoshiko Nanao
- School of Physics and Astronomy, University of St Andrews, Fife, KY16 9SS, Scotland
| | - Hiroyoshi Nobukane
- Center of Education and Research for Topological Science and Technology, Hokkaido University, Sapporo, 060-8628, Japan
- Department of Physics, Hokkaido University, Sapporo, 060-0810, Japan
| | - Hideaki Obuse
- Department of Applied Physics, Hokkaido University, Sapporo, 060-8628, Japan
- Center of Education and Research for Topological Science and Technology, Hokkaido University, Sapporo, 060-8628, Japan
| | - Satoshi Tanda
- Department of Applied Physics, Hokkaido University, Sapporo, 060-8628, Japan
- Center of Education and Research for Topological Science and Technology, Hokkaido University, Sapporo, 060-8628, Japan
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7
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Tromp WO, Benschop T, Ge JF, Battisti I, Bastiaans KM, Chatzopoulos D, Vervloet AHM, Smit S, van Heumen E, Golden MS, Huang Y, Kondo T, Takeuchi T, Yin Y, Hoffman JE, Sulangi MA, Zaanen J, Allan MP. Puddle formation and persistent gaps across the non-mean-field breakdown of superconductivity in overdoped (Pb,Bi) 2Sr 2CuO 6+δ. NATURE MATERIALS 2023; 22:703-709. [PMID: 36879002 DOI: 10.1038/s41563-023-01497-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2022] [Accepted: 01/31/2023] [Indexed: 06/03/2023]
Abstract
The cuprate high-temperature superconductors exhibit many unexplained electronic phases, but the superconductivity at high doping is often believed to be governed by conventional mean-field Bardeen-Cooper-Schrieffer theory1. However, it was shown that the superfluid density vanishes when the transition temperature goes to zero2,3, in contradiction to expectations from Bardeen-Cooper-Schrieffer theory. Our scanning tunnelling spectroscopy measurements in the overdoped regime of the (Pb,Bi)2Sr2CuO6+δ high-temperature superconductor show that this is due to the emergence of nanoscale superconducting puddles in a metallic matrix4,5. Our measurements further reveal that this puddling is driven by gap filling instead of gap closing. The important implication is that it is not a diminishing pairing interaction that causes the breakdown of superconductivity. Unexpectedly, the measured gap-to-filling correlation also reveals that pair breaking by disorder does not play a dominant role and that the mechanism of superconductivity in overdoped cuprate superconductors is qualitatively different from conventional mean-field theory.
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Affiliation(s)
- Willem O Tromp
- Leiden Institute of Physics, Leiden University, Leiden, The Netherlands
| | - Tjerk Benschop
- Leiden Institute of Physics, Leiden University, Leiden, The Netherlands
| | - Jian-Feng Ge
- Leiden Institute of Physics, Leiden University, Leiden, The Netherlands
| | - Irene Battisti
- Leiden Institute of Physics, Leiden University, Leiden, The Netherlands
| | - Koen M Bastiaans
- Leiden Institute of Physics, Leiden University, Leiden, The Netherlands
- Department of Quantum Nanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Delft, The Netherlands
| | | | | | - Steef Smit
- Institute of Physics, University of Amsterdam, Amsterdam, The Netherlands
| | - Erik van Heumen
- Institute of Physics, University of Amsterdam, Amsterdam, The Netherlands
- QuSoft, Amsterdam, The Netherlands
| | - Mark S Golden
- Institute of Physics, University of Amsterdam, Amsterdam, The Netherlands
| | - Yinkai Huang
- Institute of Physics, University of Amsterdam, Amsterdam, The Netherlands
| | - Takeshi Kondo
- Institute for Solid State Physics, University of Tokyo, Kashiwa, Japan
| | | | - Yi Yin
- Zhejiang Province Key Laboratory of Quantum Technology and Device, Department of Physics, Zhejiang University, Hangzhou, China
- Collaborative Innovation Centre of Advanced Microstructures, Nanjing University, Nanjiang, China
| | | | - Miguel Antonio Sulangi
- Department of Physics, University of Florida, Gainesville, FL, USA
- National Institute of Physics, College of Science, University of the Philippines, Diliman, Quezon City, Philippines
| | - Jan Zaanen
- Institute-Lorentz for Theoretical Physics, Leiden University, Leiden, The Netherlands
| | - Milan P Allan
- Leiden Institute of Physics, Leiden University, Leiden, The Netherlands.
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8
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Diamantini MC, Trugenberger CA, Chen SZ, Lu YJ, Liang CT, Vinokur VM. Type-III Superconductivity. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2206523. [PMID: 36965030 DOI: 10.1002/advs.202206523] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 02/19/2023] [Indexed: 05/18/2023]
Abstract
Superconductivity remains one of most fascinating quantum phenomena existing on a macroscopic scale. Its rich phenomenology is usually described by the Ginzburg-Landau (GL) theory in terms of the order parameter, representing the macroscopic wave function of the superconducting condensate. The GL theory addresses one of the prime superconducting properties, screening of the electromagnetic field because it becomes massive within a superconductor, the famous Anderson-Higgs mechanism. Here the authors describe another widely-spread type of superconductivity where the Anderson-Higgs mechanism does not work and must be replaced by the Deser-Jackiw-Templeton topological mass generation and, correspondingly, the GL effective field theory must be replaced by an effective topological gauge theory. These superconductors are inherently inhomogeneous granular superconductors, where electronic granularity is either fundamental or emerging. It is shown that the corresponding superconducting transition is a 3D generalization of the 2D Berezinskii-Kosterlitz-Thouless vortex binding-unbinding transition. The binding-unbinding of the line-like vortices in 3D results in the Vogel-Fulcher-Tamman scaling of the resistance near the superconducting transition. The authors report experimental data fully confirming the VFT behavior of the resistance.
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Affiliation(s)
- M Cristina Diamantini
- NiPS Laboratory, INFN and Dipartimento di Fisica e Geologia, University of Perugia, via A. Pascoli, Perugia, I-06100, Italy
| | | | - Sheng-Zong Chen
- Department of Physics, National Taiwan University, Taipei, 106, Taiwan
| | - Yu-Jung Lu
- Department of Physics, National Taiwan University, Taipei, 106, Taiwan
- Research Center for Applied Sciences, Academia Sinica, Taipei, 115, Taiwan
| | - Chi-Te Liang
- Department of Physics, National Taiwan University, Taipei, 106, Taiwan
- Center for Quantum Science and Engineering, National Taiwan University, Taipei, 106, Taiwan
| | - Valerii M Vinokur
- Terra Quantum AG, Kornhausstrasse 25, St. Gallen, CH-9000, Switzerland
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9
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van Weerdenburg WM, Kamlapure A, Fyhn EH, Huang X, van Mullekom NP, Steinbrecher M, Krogstrup P, Linder J, Khajetoorians AA. Extreme enhancement of superconductivity in epitaxial aluminum near the monolayer limit. SCIENCE ADVANCES 2023; 9:eadf5500. [PMID: 36857452 PMCID: PMC9977180 DOI: 10.1126/sciadv.adf5500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Accepted: 01/31/2023] [Indexed: 06/18/2023]
Abstract
BCS theory has been widely successful at describing elemental bulk superconductors. Yet, as the length scales of such superconductors approach the atomic limit, dimensionality as well as the environment of the superconductor can lead to drastically different and unpredictable superconducting behavior. Here, we report a threefold enhancement of the superconducting critical temperature and gap size in ultrathin epitaxial Al films on Si(111), when approaching the 2D limit, based on high-resolution scanning tunneling microscopy/spectroscopy (STM/STS) measurements. Using spatially resolved spectroscopy, we characterize the vortex structure in the presence of a strong Zeeman field and find evidence of a paramagnetic Meissner effect originating from odd-frequency pairing contributions. These results illustrate two notable influences of reduced dimensionality on a BCS superconductor and present a platform to study BCS superconductivity in large magnetic fields.
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Affiliation(s)
| | - Anand Kamlapure
- Institute for Molecules and Materials, Radboud University, 6525 AJ Nijmegen, Netherlands
| | - Eirik Holm Fyhn
- Center for Quantum Spintronics, Department of Physics, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway
| | - Xiaochun Huang
- Institute for Molecules and Materials, Radboud University, 6525 AJ Nijmegen, Netherlands
| | | | - Manuel Steinbrecher
- Institute for Molecules and Materials, Radboud University, 6525 AJ Nijmegen, Netherlands
| | - Peter Krogstrup
- NNF Quantum Computing Programme, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Jacob Linder
- Center for Quantum Spintronics, Department of Physics, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway
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10
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Orbital-selective hole and hole-pair formation and Bose condensation in high-temperature superconductors. J SOLID STATE CHEM 2022. [DOI: 10.1016/j.jssc.2022.123529] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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11
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Tamir I, Caspari V, Rolf D, Lotze C, Franke KJ. Shot-noise measurements of single-atom junctions using a scanning tunneling microscope. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2022; 93:023702. [PMID: 35232162 DOI: 10.1063/5.0078917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Accepted: 01/26/2022] [Indexed: 06/14/2023]
Abstract
Current fluctuations related to the discreteness of charge passing through small constrictions are termed shot noise. This unavoidable noise provides both advantages-being a direct measurement of the transmitted particles' charge-and disadvantages-a main noise source in nanoscale devices operating at low temperature. While better understanding of shot noise is desired, the technical difficulties in measuring it result in relatively few experimental works, especially in single-atom structures. Here, we describe a local shot-noise measurement apparatus and demonstrate successful noise measurements through single-atom junctions. Our apparatus, based on a scanning tunneling microscope, operates at liquid helium temperatures. It includes a broadband commercial amplifier mounted in close proximity to the tunnel junction, thus reducing both the thermal noise and input capacitance that limit traditional noise measurements. The full capabilities of the microscope are maintained in the modified system, and a quick transition between different measurement modes is possible.
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Affiliation(s)
- Idan Tamir
- Fachbereich Physik, Freie Universität Berlin, 14195 Berlin, Germany
| | - Verena Caspari
- Fachbereich Physik, Freie Universität Berlin, 14195 Berlin, Germany
| | - Daniela Rolf
- Fachbereich Physik, Freie Universität Berlin, 14195 Berlin, Germany
| | - Christian Lotze
- Fachbereich Physik, Freie Universität Berlin, 14195 Berlin, Germany
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Bastiaans KM, Chatzopoulos D, Ge JF, Cho D, Tromp WO, van Ruitenbeek JM, Fischer MH, de Visser PJ, Thoen DJ, Driessen EFC, Klapwijk TM, Allan MP. Direct evidence for Cooper pairing without a spectral gap in a disordered superconductor above Tc. Science 2021; 374:608-611. [PMID: 34709897 DOI: 10.1126/science.abe3987] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
[Figure: see text].
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Affiliation(s)
- Koen M Bastiaans
- Leiden Institute of Physics, Leiden University, 2333 CA Leiden, Netherlands
| | | | - Jian-Feng Ge
- Leiden Institute of Physics, Leiden University, 2333 CA Leiden, Netherlands
| | - Doohee Cho
- Department of Physics, Yonsei University, Seoul 03722, Republic of Korea
| | - Willem O Tromp
- Leiden Institute of Physics, Leiden University, 2333 CA Leiden, Netherlands
| | | | - Mark H Fischer
- Department of Physics, University of Zurich, 8057 Zurich, Switzerland
| | - Pieter J de Visser
- SRON Netherlands Institute for Space Research, 2333 CA Leiden Netherlands
| | - David J Thoen
- Kavli Institute of Nanoscience, Delft University of Technology, 2628 CJ Delft, Netherlands.,Faculty of Electrical Engineering, Mathematics and Computer Science, Delft University of Technology, 2628 CD Delft, Netherlands
| | - Eduard F C Driessen
- Institut de Radioastronomie Millimétrique (IRAM), Grenoble, 38400 Saint-Martin-d'Hères, France
| | - Teunis M Klapwijk
- Kavli Institute of Nanoscience, Delft University of Technology, 2628 CJ Delft, Netherlands.,Institute of Topological Materials, Julius-Maximilian-Universität Würzburg, 97070 Würzburg, Germany
| | - Milan P Allan
- Leiden Institute of Physics, Leiden University, 2333 CA Leiden, Netherlands
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