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Ziesen A, Altland A, Egger R, Hassler F. Statistical Majorana Bound State Spectroscopy. PHYSICAL REVIEW LETTERS 2023; 130:106001. [PMID: 36962051 DOI: 10.1103/physrevlett.130.106001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Accepted: 02/21/2023] [Indexed: 06/18/2023]
Abstract
Tunnel spectroscopy data for the detection of Majorana bound states (MBS) is often criticized for its proneness to misinterpretation of genuine MBS with low-lying Andreev bound states. Here, we suggest a protocol removing this ambiguity by extending single shot measurements to sequences performed at varying system parameters. We demonstrate how such sampling, which we argue requires only moderate effort for current experimental platforms, resolves the statistics of Andreev side lobes, thus providing compelling evidence for the presence or absence of a Majorana center peak.
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Affiliation(s)
- Alexander Ziesen
- JARA Institute for Quantum Information, RWTH Aachen University, 52056 Aachen, Germany
| | - Alexander Altland
- Institut für Theoretische Physik, Universität zu Köln, Zülpicher Straße 77, 50937 Köln, Germany
| | - Reinhold Egger
- Institut für Theoretische Physik, Heinrich-Heine-Universität, D-40225 Düsseldorf, Germany
| | - Fabian Hassler
- JARA Institute for Quantum Information, RWTH Aachen University, 52056 Aachen, Germany
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2
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Wei M, Wang L, Wang B, Xiang L, Xu F, Wang B, Wang J. Quantum Fluctuation of the Quantum Geometric Tensor and Its Manifestation as Intrinsic Hall Signatures in Time-Reversal Invariant Systems. PHYSICAL REVIEW LETTERS 2023; 130:036202. [PMID: 36763382 DOI: 10.1103/physrevlett.130.036202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Accepted: 12/13/2022] [Indexed: 06/18/2023]
Abstract
In time-reversal invariant systems, all charge Hall effects predicted so far are extrinsic effects due to the dependence on the relaxation time. We explore intrinsic Hall signatures by studying the quantum noise spectrum of the Hall current in time-reversal invariant systems, and discover intrinsic thermal Hall noises in both linear and nonlinear regimes. As the band geometric characteristics, quantum geometric tensor and Berry curvature play critical roles in various Hall effects; so do their quantum fluctuations. It is found that the thermal Hall noise in linear order of the electric field is purely intrinsic, and the second-order thermal Hall noise has both intrinsic and extrinsic contributions. In particular, the intrinsic part of the second-order thermal Hall noise is a manifestation of the quantum fluctuation of the quantum geometric tensor, which widely exists as long as Berry curvature is nonzero. These intrinsic thermal Hall noises provide direct measurable means to band geometric information, including Berry curvature related quantities and quantum fluctuation of quantum geometric tensor.
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Affiliation(s)
- Miaomiao Wei
- College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China
| | - Luyang Wang
- College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China
| | - Bin Wang
- College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China
| | - Longjun Xiang
- College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China
| | - Fuming Xu
- College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China
| | - Baigeng Wang
- National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093, China
- Collaborative Innovation Center for Advanced Microstructures, Nanjing 210093, China
| | - Jian Wang
- College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China
- Department of Physics, The University of Hong Kong, Pokfulam Road, Hong Kong, China
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3
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Ricco LS, Sanches JE, Marques Y, de Souza M, Figueira MS, Shelykh IA, Seridonio AC. Topological isoconductance signatures in Majorana nanowires. Sci Rep 2021; 11:17310. [PMID: 34453069 PMCID: PMC8397770 DOI: 10.1038/s41598-021-96415-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Accepted: 08/04/2021] [Indexed: 11/23/2022] Open
Abstract
We consider transport properties of a hybrid device composed by a quantum dot placed between normal and superconducting reservoirs, and coupled to a Majorana nanowire: a topological superconducting segment hosting Majorana bound states (MBSs) at the opposite ends. It is demonstrated that if highly nonlocal and nonoverlapping MBSs are formed in the system, the zero-bias Andreev conductance through the dot exhibits characteristic isoconductance profiles with the shape depending on the spin asymmetry of the coupling between the dot and the topological superconductor. Otherwise, for overlapping MBSs with less degree of nonlocality, the conductance is insensitive to the spin polarization and the isoconductance signatures disappear. This allows to propose an alternative experimental protocol for probing the nonlocality of the MBSs in Majorana nanowires.
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Affiliation(s)
- L S Ricco
- Science Institute, University of Iceland, Dunhagi-3, 107, Reykjavik, Iceland.
| | - J E Sanches
- School of Engineering, Department of Physics and Chemistry, São Paulo State University (Unesp), 15385-000, Ilha Solteira, SP, Brazil
| | - Y Marques
- Department of Physics, ITMO University, 197101, St. Petersburg, Russia
| | - M de Souza
- Department of Physics, São Paulo State University (Unesp), IGCE, 13506-970, Rio Claro, SP, Brazil
| | - M S Figueira
- Instituto de Física, Universidade Federal Fluminense, 24210-340, Niterói, Rio de Janeiro, Brazil
| | - I A Shelykh
- Science Institute, University of Iceland, Dunhagi-3, 107, Reykjavik, Iceland
- Department of Physics, ITMO University, 197101, St. Petersburg, Russia
| | - A C Seridonio
- School of Engineering, Department of Physics and Chemistry, São Paulo State University (Unesp), 15385-000, Ilha Solteira, SP, Brazil
- Department of Physics, São Paulo State University (Unesp), IGCE, 13506-970, Rio Claro, SP, Brazil
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Chatzopoulos D, Cho D, Bastiaans KM, Steffensen GO, Bouwmeester D, Akbari A, Gu G, Paaske J, Andersen BM, Allan MP. Spatially dispersing Yu-Shiba-Rusinov states in the unconventional superconductor FeTe 0.55Se 0.45. Nat Commun 2021; 12:298. [PMID: 33436594 PMCID: PMC7804303 DOI: 10.1038/s41467-020-20529-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 12/07/2020] [Indexed: 01/29/2023] Open
Abstract
By using scanning tunneling microscopy (STM) we find and characterize dispersive, energy-symmetric in-gap states in the iron-based superconductor FeTe0.55Se0.45, a material that exhibits signatures of topological superconductivity, and Majorana bound states at vortex cores or at impurity locations. We use a superconducting STM tip for enhanced energy resolution, which enables us to show that impurity states can be tuned through the Fermi level with varying tip-sample distance. We find that the impurity state is of the Yu-Shiba-Rusinov (YSR) type, and argue that the energy shift is caused by the low superfluid density in FeTe0.55Se0.45, which allows the electric field of the tip to slightly penetrate the sample. We model the newly introduced tip-gating scenario within the single-impurity Anderson model and find good agreement to the experimental data.
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Affiliation(s)
- Damianos Chatzopoulos
- grid.5132.50000 0001 2312 1970Leiden Institute of Physics, Leiden University, Niels Bohrweg 2, Leiden, CA 2333 The Netherlands
| | - Doohee Cho
- grid.5132.50000 0001 2312 1970Leiden Institute of Physics, Leiden University, Niels Bohrweg 2, Leiden, CA 2333 The Netherlands ,grid.15444.300000 0004 0470 5454Department of Physics, Yonsei University, Seoul, 03722 Republic of Korea
| | - Koen M. Bastiaans
- grid.5132.50000 0001 2312 1970Leiden Institute of Physics, Leiden University, Niels Bohrweg 2, Leiden, CA 2333 The Netherlands
| | - Gorm O. Steffensen
- grid.5254.60000 0001 0674 042XCenter for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, Copenhagen Ø, 2100 Denmark
| | - Damian Bouwmeester
- grid.5132.50000 0001 2312 1970Leiden Institute of Physics, Leiden University, Niels Bohrweg 2, Leiden, CA 2333 The Netherlands ,grid.5292.c0000 0001 2097 4740Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, Delft, CJ 2628 Netherlands
| | - Alireza Akbari
- grid.419507.e0000 0004 0491 351XMax Planck Institute for the Chemical Physics of Solids, Dresden, D-01187 Germany ,grid.49100.3c0000 0001 0742 4007Max Planck POSTECH Center for Complex Phase Materials, and Department of Physics, POSTECH, Pohang, Gyeongbuk 790-784 Korea
| | - Genda Gu
- grid.202665.50000 0001 2188 4229Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, NY 11973 USA
| | - Jens Paaske
- grid.5254.60000 0001 0674 042XCenter for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, Copenhagen Ø, 2100 Denmark
| | - Brian M. Andersen
- grid.5254.60000 0001 0674 042XCenter for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, Copenhagen Ø, 2100 Denmark
| | - Milan P. Allan
- grid.5132.50000 0001 2312 1970Leiden Institute of Physics, Leiden University, Niels Bohrweg 2, Leiden, CA 2333 The Netherlands
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Manousakis J, Wille C, Altland A, Egger R, Flensberg K, Hassler F. Weak Measurement Protocols for Majorana Bound State Identification. PHYSICAL REVIEW LETTERS 2020; 124:096801. [PMID: 32202888 DOI: 10.1103/physrevlett.124.096801] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Accepted: 01/22/2020] [Indexed: 06/10/2023]
Abstract
We propose a continuous weak measurement protocol testing the nonlocality of Majorana bound states through current shot noise correlations. The experimental setup contains a topological superconductor island with three normal-conducting leads weakly coupled to different Majorana states. Putting one lead at finite voltage and measuring the shot noise correlations between the other two (grounded) leads, devices with true Majorana states are distinguished from those without by strong current correlations. The presence of true Majorana states manifests itself in unusually high noise levels or the near absence of noise, depending on the chosen device configuration. Monitoring the noise statistics amounts to a weak continuous measurement of the Majorana qubit and yields information similar to that of a full braiding protocol, but at much lower experimental effort. Our theory can be adapted to different platforms and should allow for the clear identification of Majorana states.
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Affiliation(s)
- J Manousakis
- Institut für theoretische Physik, Universität zu Köln, Zülpicher Straße 77, D-50937 Köln, Germany
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, DK-2100 Copenhagen, Denmark
| | - C Wille
- Dahlem Center for Complex Quantum Systems, Physics Department, Freie Universität Berlin, D-14195 Berlin, Germany
| | - A Altland
- Institut für theoretische Physik, Universität zu Köln, Zülpicher Straße 77, D-50937 Köln, Germany
| | - R Egger
- Institut für Theoretische Physik, Heinrich Heine Universität, D-40225 Düsseldorf, Germany
| | - K Flensberg
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, DK-2100 Copenhagen, Denmark
| | - F Hassler
- JARA-Institute for Quantum Information, RWTH Aachen University, D-52056 Aachen, Germany
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