1
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Man H, Iguchi Y, Bao JK, Chung DY, Kanatzidis MG. In Situ Local Imaging of Ferromagnetism and Superconductivity in RbEuFe 4As 4. NANO LETTERS 2024; 24:9082-9087. [PMID: 39007862 DOI: 10.1021/acs.nanolett.4c02475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/16/2024]
Abstract
The coexistence of superconductivity and ferromagnetism is an intrinsically interesting research focus in condensed matter physics, but the study is limited by low superconducting (Tc) and magnetic (Tm) transition temperatures in related materials. Here, we used a scanning superconducting quantum interference device to image the in situ diamagnetic and ferromagnetic responses of RbEuFe4As4 with high Tc and Tm. We observed significant suppression of the superfluid density in the vicinity of the magnetic phase transition, signifying fluctuation-enhanced magnetic scatterings between Eu spins and Fe 3d conduction electrons. Intriguingly, we observed multiple ferromagnetic domains that should be absent in an ideal magnetic helical phase. The formation of these domains demonstrates a weak c-axis ferromagnetic component probably arising from the Eu spin-canting effect, indicative of possible superconductivity-driven domain Meissner and domain vortex-antivortex phases, as revealed in EuFe2(As0.79P0.21)2. Our observations highlight that RbEuFe4As4 is a unique system that includes multiple interplay channels between superconductivity and ferromagnetism.
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Affiliation(s)
- Huiyuan Man
- Geballe Laboratory for Advanced Materials, Stanford University, Stanford, California 94305, United States
- Stanford Nano Shared Facilities, Stanford University, Stanford, California 94305, United States
| | - Yusuke Iguchi
- Geballe Laboratory for Advanced Materials, Stanford University, Stanford, California 94305, United States
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Jin-Ke Bao
- Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, United States
| | - Duck Young Chung
- Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, United States
| | - Mercouri G Kanatzidis
- Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, United States
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
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2
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Keren I, Gutfreund A, Noah A, Fridman N, Di Bernardo A, Steinberg H, Anahory Y. Chip-Integrated Vortex Manipulation. NANO LETTERS 2023; 23:4669-4674. [PMID: 36917692 DOI: 10.1021/acs.nanolett.3c00324] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
The positions of Abrikosov vortices have long been considered as means to encode classical information. Although it is possible to move individual vortices using local probes, the challenge of scalable on-chip vortex-control remains outstanding, especially when considering the demands of controlling multiple vortices. Realization of vortex logic requires means to shuttle vortices reliably between engineered pinning potentials, while concomitantly keeping all other vortices fixed. We demonstrate such capabilities using Nb loops patterned below a NbSe2 layer. SQUID-on-Tip (SOT) microscopy reveals that the loops localize vortices in designated sites to a precision better than 100 nm; they realize "push" and "pull" operations of vortices as far as 3 μm. Successive application of such operations shuttles a vortex between adjacent loops. Our results may be used as means to integrate vortices in future quantum circuitry. Strikingly, we demonstrate a winding operation, paving the way for future topological quantum computing and simulations.
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Affiliation(s)
- Itai Keren
- Racah Institute of Physics, The Hebrew University, Jerusalem 91904, Israel
| | - Alon Gutfreund
- Racah Institute of Physics, The Hebrew University, Jerusalem 91904, Israel
| | - Avia Noah
- Racah Institute of Physics, The Hebrew University, Jerusalem 91904, Israel
| | - Nofar Fridman
- Racah Institute of Physics, The Hebrew University, Jerusalem 91904, Israel
| | - Angelo Di Bernardo
- Department of Physics, University of Konstanz, Universitätstrasse 10, 78457 Konstanz, Germany
| | - Hadar Steinberg
- Racah Institute of Physics, The Hebrew University, Jerusalem 91904, Israel
- Center for Nanoscience and Nanotechnology, Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Yonathan Anahory
- Racah Institute of Physics, The Hebrew University, Jerusalem 91904, Israel
- Center for Nanoscience and Nanotechnology, Hebrew University of Jerusalem, Jerusalem 91904, Israel
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3
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Direct observation of vortices in an electron fluid. Nature 2022; 607:74-80. [PMID: 35794267 DOI: 10.1038/s41586-022-04794-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2022] [Accepted: 04/22/2022] [Indexed: 11/09/2022]
Abstract
Vortices are the hallmarks of hydrodynamic flow. Strongly interacting electrons in ultrapure conductors can display signatures of hydrodynamic behaviour, including negative non-local resistance1-4, higher-than-ballistic conduction5-7, Poiseuille flow in narrow channels8-10 and violation of the Wiedemann-Franz law11. Here we provide a visualization of whirlpools in an electron fluid. By using a nanoscale scanning superconducting quantum interference device on a tip12, we image the current distribution in a circular chamber connected through a small aperture to a current-carrying strip in the high-purity type II Weyl semimetal WTe2. In this geometry, the Gurzhi momentum diffusion length and the size of the aperture determine the vortex stability phase diagram. We find that vortices are present for only small apertures, whereas the flow is laminar (non-vortical) for larger apertures. Near the vortical-to-laminar transition, we observe the single vortex in the chamber splitting into two vortices; this behaviour is expected only in the hydrodynamic regime and is not anticipated for ballistic transport. These findings suggest a new mechanism of hydrodynamic flow in thin pure crystals such that the spatial diffusion of electron momenta is enabled by small-angle scattering at the surfaces instead of the routinely invoked electron-electron scattering, which becomes extremely weak at low temperatures. This surface-induced para-hydrodynamics, which mimics many aspects of conventional hydrodynamics including vortices, opens new possibilities for exploring and using electron fluidics in high-mobility electron systems.
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4
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Multi-Steps Magnetic Flux Entrance/Exit at Thermomagnetic Avalanches in the Plates of Hard Superconductors. MATERIALS 2022; 15:ma15062037. [PMID: 35329489 PMCID: PMC8949376 DOI: 10.3390/ma15062037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/12/2022] [Revised: 03/07/2022] [Accepted: 03/08/2022] [Indexed: 02/05/2023]
Abstract
Avalanche cascades of magnetic flux have been detected at thermomagnetic instability of the critical state in the plates of Nb-Ti alloy. It was found that, the magnetic flux Φ enters conventional superconductor in screening regime and leaves in trapping regime in the form of a multistage "stairways", with the structure dependent on the magnetic field strength and magnetic history, with approximately equal successive portions ΔΦ in temporal Φ(t) dependence, and with the width depending almost linearly on the plate thickness. The steady generation of cascades was observed for the full remagnetization cycle in the field of 2-4 T. The structure of inductive signal becomes complex already in the field of 0-2 T and it was shown, on the base of Fourier analysis, that, the avalanche flux dynamic produces, in this field range, multiple harmonics of the electric field. The physical reason of complex spectrum of the low-field avalanche dynamics can be associated with rough structure of moving flux front and with inhomogeneous relief of induction. It was established that the initiation of cascades occurs mainly in the central part of the lateral surface. The mechanism of cascades generation seems to be connected to the "resonator's properties" of the plates.
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5
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Anahory Y, Naren HR, Lachman EO, Buhbut Sinai S, Uri A, Embon L, Yaakobi E, Myasoedov Y, Huber ME, Klajn R, Zeldov E. SQUID-on-tip with single-electron spin sensitivity for high-field and ultra-low temperature nanomagnetic imaging. NANOSCALE 2020; 12:3174-3182. [PMID: 31967152 DOI: 10.1039/c9nr08578e] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Scanning nanoscale superconducting quantum interference devices (nanoSQUIDs) are of growing interest for highly sensitive quantitative imaging of magnetic, spintronic, and transport properties of low-dimensional systems. Utilizing specifically designed grooved quartz capillaries pulled into a sharp pipette, we have fabricated the smallest SQUID-on-tip (SOT) devices with effective diameters down to 39 nm. Integration of a resistive shunt in close proximity to the pipette apex combined with self-aligned deposition of In and Sn, has resulted in SOTs with a flux noise of 42 nΦ0 Hz-1/2, yielding a record low spin noise of 0.29 μB Hz-1/2. In addition, the new SOTs function at sub-Kelvin temperatures and in high magnetic fields of over 2.5 T. Integrating the SOTs into a scanning probe microscope allowed us to image the stray field of a single Fe3O4 nanocube at 300 mK. Our results show that the easy magnetization axis direction undergoes a transition from the 〈111〉 direction at room temperature to an in-plane orientation, which could be attributed to the Verwey phase transition in Fe3O4.
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Affiliation(s)
- Y Anahory
- Racah Institute of Physics, The Hebrew University, Jerusalem 9190401, Israel.
| | - H R Naren
- Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - E O Lachman
- Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - S Buhbut Sinai
- Department of Organic Chemistry, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - A Uri
- Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - L Embon
- Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - E Yaakobi
- Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Y Myasoedov
- Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - M E Huber
- Departments of Physics and Electrical Engineering, University of Colorado Denver, Denver 80217, USA
| | - R Klajn
- Department of Organic Chemistry, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - E Zeldov
- Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot 7610001, Israel
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6
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Polshyn H, Naibert T, Budakian R. Manipulating Multivortex States in Superconducting Structures. NANO LETTERS 2019; 19:5476-5482. [PMID: 31246034 DOI: 10.1021/acs.nanolett.9b01983] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
We demonstrate a method for manipulating small ensembles of vortices in multiply connected superconducting structures. A micron-size magnetic particle attached to the tip of a silicon cantilever is used to locally apply magnetic flux through the superconducting structure. By scanning the tip over the surface of the device and by utilizing the dynamical coupling between the vortices and the cantilever, a high-resolution spatial map of the different vortex configurations is obtained. Moving the tip to a particular location in the map stabilizes a distinct multivortex configuration. Thus, the scanning of the tip over a particular trajectory in space permits nontrivial operations to be performed, such as braiding of individual vortices within a larger vortex ensemble-a key capability required by many proposals for topological quantum computing.
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Affiliation(s)
- Hryhoriy Polshyn
- Department of Physics , University of Illinois at Urbana-Champaign , Urbana , Illinois 61801 , United States
- Department of Physics , University of California , Santa Barbara , California 93106 , United States
| | - Tyler Naibert
- Department of Physics , University of Illinois at Urbana-Champaign , Urbana , Illinois 61801 , United States
| | - Raffi Budakian
- Department of Physics , University of Illinois at Urbana-Champaign , Urbana , Illinois 61801 , United States
- Department of Physics , University of Waterloo , Waterloo , ON , Canada , N2L3G1
- Institute for Quantum Computing , University of Waterloo , Waterloo , ON , Canada , N2L3G1
- Perimeter Institute for Theoretical Physics , Waterloo , ON , Canada , N2L2Y5
- Canadian Institute for Advanced Research , Toronto , ON , Canada , M5G1Z8
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7
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Estellés-Duart F, Ortuño M, Somoza AM, Vinokur VM, Gurevich A. Current-driven production of vortex-antivortex pairs in planar Josephson junction arrays and phase cracks in long-range order. Sci Rep 2018; 8:15460. [PMID: 30337558 PMCID: PMC6193993 DOI: 10.1038/s41598-018-33467-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Accepted: 09/26/2018] [Indexed: 11/27/2022] Open
Abstract
Proliferation of topological defects like vortices and dislocations plays a key role in the physics of systems with long-range order, particularly, superconductivity and superfluidity in thin films, plasticity of solids, and melting of atomic monolayers. Topological defects are characterized by their topological charge reflecting fundamental symmetries and conservation laws of the system. Conservation of topological charge manifests itself in extreme stability of static topological defects because destruction of a single defect requires overcoming a huge energy barrier proportional to the system size. However, the stability of driven topological defects remains largely unexplored. Here we address this issue and investigate numerically a dynamic instability of moving vortices in planar arrays of Josephson junctions. We show that a single vortex driven by sufficiently strong current becomes unstable and destroys superconductivity by triggering a chain reaction of self-replicating vortex-antivortex pairs forming linear of branching expanding patterns. This process can be described in terms of propagating phase cracks in long-range order with far-reaching implications for dynamic systems of interacting spins and atoms hosting magnetic vortices and dislocations.
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Affiliation(s)
| | - Miguel Ortuño
- Universidad de Murcia, Departamento de Física-CIOyN, Murcia, 30071, Spain
| | - Andrés M Somoza
- Universidad de Murcia, Departamento de Física-CIOyN, Murcia, 30071, Spain
| | - Valerii M Vinokur
- Argonne National Laboratory, Materials Science Division, Chicago, IL, 60637, USA.,Univeristy of Chicago, Computation Institute, Chicago, IL, 60637, USA
| | - Alex Gurevich
- Old Dominion University, Department of Physics, Norfolk, VA, 23529, USA
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8
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Abstract
AbstractThe behavior of vortices at microwave frequencies is an extremely useful source of information on the microscopic parameters that enter the description of the vortex dynamics. This feature has acquired particular relevance since the discovery of unusual superconductors, such as cuprates. Microwave investigation then extended its field of application to many families of superconductors, including the artificially nanostructured materials. It is then important to understand the basics of the physics of vortices moving at high frequency, as well as to understand what information the experiments can yield (and what they can not). The aim of this brief review is to introduce the readers to some basic aspects of the physics of vortices under a microwave electromagnetic field, and to guide them to an understanding of the experiment, also by means of the illustration of some relevant results.
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9
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Dobrovolskiy OV, Huth M, Shklovskij VA, Vovk RV. Mobile fluxons as coherent probes of periodic pinning in superconductors. Sci Rep 2017; 7:13740. [PMID: 29062080 PMCID: PMC5653780 DOI: 10.1038/s41598-017-14232-z] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Accepted: 10/06/2017] [Indexed: 11/17/2022] Open
Abstract
The interaction of (quasi)particles with a periodic potential arises in various domains of science and engineering, such as solid-state physics, chemical physics, and communication theory. An attractive test ground to investigate this interaction is represented by superconductors with artificial pinning sites, where magnetic flux quanta (Abrikosov vortices) interact with the pinning potential U(r) = U(r + R) induced by a nanostructure. At a combination of microwave and dc currents, fluxons act as mobile probes of U(r): The ac component shakes the fluxons in the vicinity of their equilibrium points which are unequivocally determined by the local pinning force counterbalanced by the Lorentz force induced by the dc current, linked to the curvature of U(r) which can then be used for a successful fitting of the voltage responses. A good correlation of the deduced dependences U(r) with the cross sections of the nanostructures points to that pinning is primarily caused by vortex length reduction. Our findings pave a new route to a non-destructive evaluation of periodic pinning in superconductor thin films. The approach should also apply to a broad class of systems whose evolution in time can be described by the coherent motion of (quasi)particles in a periodic potential.
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Affiliation(s)
- Oleksandr V Dobrovolskiy
- Physikalisches Institut, Goethe University, Frankfurt am Main, 60438, Germany. .,Physics Department, V. Karazin Kharkiv National University, Kharkiv, 61022, Ukraine.
| | - Michael Huth
- Physikalisches Institut, Goethe University, Frankfurt am Main, 60438, Germany
| | - Valerij A Shklovskij
- Physics Department, V. Karazin Kharkiv National University, Kharkiv, 61022, Ukraine
| | - Ruslan V Vovk
- Physics Department, V. Karazin Kharkiv National University, Kharkiv, 61022, Ukraine
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10
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Imaging of super-fast dynamics and flow instabilities of superconducting vortices. Nat Commun 2017; 8:85. [PMID: 28729642 PMCID: PMC5519736 DOI: 10.1038/s41467-017-00089-3] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Accepted: 06/01/2017] [Indexed: 11/08/2022] Open
Abstract
Quantized magnetic vortices driven by electric current determine key electromagnetic properties of superconductors. While the dynamic behavior of slow vortices has been thoroughly investigated, the physics of ultrafast vortices under strong currents remains largely unexplored. Here, we use a nanoscale scanning superconducting quantum interference device to image vortices penetrating into a superconducting Pb film at rates of tens of GHz and moving with velocities of up to tens of km/s, which are not only much larger than the speed of sound but also exceed the pair-breaking speed limit of superconducting condensate. These experiments reveal formation of mesoscopic vortex channels which undergo cascades of bifurcations as the current and magnetic field increase. Our numerical simulations predict metamorphosis of fast Abrikosov vortices into mixed Abrikosov-Josephson vortices at even higher velocities. This work offers an insight into the fundamental physics of dynamic vortex states of superconductors at high current densities, crucial for many applications.Ultrafast vortex dynamics driven by strong currents define eletromagnetic properties of superconductors, but it remains unexplored. Here, Embon et al. use a unique scanning microscopy technique to image steady-state penetration of super-fast vortices into a superconducting Pb film at rates of tens of GHz and velocities up to tens of km/s.
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11
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Uri A, Meltzer AY, Anahory Y, Embon L, Lachman EO, Halbertal D, Hr N, Myasoedov Y, Huber ME, Young AF, Zeldov E. Electrically Tunable Multiterminal SQUID-on-Tip. NANO LETTERS 2016; 16:6910-6915. [PMID: 27672705 DOI: 10.1021/acs.nanolett.6b02841] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We present a new nanoscale superconducting quantum interference device (SQUID) whose interference pattern can be shifted electrically in situ. The device consists of a nanoscale four-terminal-four-junction SQUID fabricated at the apex of a sharp pipet using a self-aligned three-step deposition of Pb. In contrast to conventional two-terminal-two-junction SQUIDs that display optimal sensitivity when flux biased to about a quarter of the flux quantum, the additional terminals and junctions allow optimal sensitivity at arbitrary applied flux, thus eliminating the magnetic field "blind spots". We demonstrate spin sensitivity of 5 to 8 μB/Hz1/2 over a continuous field range of 0 to 0.5 T with promising applications for nanoscale scanning magnetic imaging.
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Affiliation(s)
- Aviram Uri
- Department of Condensed Matter Physics, Weizmann Institute of Science , Rehovot 7610001, Israel
| | - Alexander Y Meltzer
- Department of Condensed Matter Physics, Weizmann Institute of Science , Rehovot 7610001, Israel
| | - Yonathan Anahory
- Department of Condensed Matter Physics, Weizmann Institute of Science , Rehovot 7610001, Israel
| | - Lior Embon
- Department of Condensed Matter Physics, Weizmann Institute of Science , Rehovot 7610001, Israel
| | - Ella O Lachman
- Department of Condensed Matter Physics, Weizmann Institute of Science , Rehovot 7610001, Israel
| | - Dorri Halbertal
- Department of Condensed Matter Physics, Weizmann Institute of Science , Rehovot 7610001, Israel
| | - Naren Hr
- Department of Condensed Matter Physics, Weizmann Institute of Science , Rehovot 7610001, Israel
| | - Yuri Myasoedov
- Department of Condensed Matter Physics, Weizmann Institute of Science , Rehovot 7610001, Israel
| | - Martin E Huber
- Department of Condensed Matter Physics, Weizmann Institute of Science , Rehovot 7610001, Israel
- Departments of Physics and Electrical Engineering, University of Colorado , Denver, Colorado 80217, United States
| | - Andrea F Young
- Department of Condensed Matter Physics, Weizmann Institute of Science , Rehovot 7610001, Israel
- Department of Physics, University of California , Broida Hall, Santa Barbara, California 93106, United States
| | - Eli Zeldov
- Department of Condensed Matter Physics, Weizmann Institute of Science , Rehovot 7610001, Israel
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12
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Abstract
Magnetic field can penetrate into type II superconductors in the form of Abrikosov vortices, which are magnetic flux tubes surrounded by circulating supercurrents often trapped at defects referred to as pinning sites. Although the average properties of the vortex matter in superconductors can be tuned with magnetic fields, temperature or electric currents, handling of individual Abrikosov vortices remains challenging and has been demonstrated only with sophisticated scanning local probe microscopies. Here we introduce a far-field optical method based on local heating of the superconductor with a focused laser beam to realize a fast and precise manipulation of individual vortices, in the same way as with optical tweezers. This simple approach provides the perfect basis for sculpting the magnetic flux profile in superconducting devices like a vortex lens or a vortex cleaner, without resorting to static pinning or ratchet effects. Manipulation of individual superconducting vortices remains challenging and has been demonstrated only in a sophisticated way. Here, Veshchunov et al. realize a fast and precise manipulation of individual vortices using a far-field optical method, providing a simple way towards optical control of Josephson transport.
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13
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Thiel L, Rohner D, Ganzhorn M, Appel P, Neu E, Müller B, Kleiner R, Koelle D, Maletinsky P. Quantitative nanoscale vortex imaging using a cryogenic quantum magnetometer. NATURE NANOTECHNOLOGY 2016; 11:677-81. [PMID: 27136133 DOI: 10.1038/nnano.2016.63] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2015] [Accepted: 03/16/2016] [Indexed: 05/05/2023]
Abstract
Microscopic studies of superconductors and their vortices play a pivotal role in understanding the mechanisms underlying superconductivity. Local measurements of penetration depths or magnetic stray fields enable access to fundamental aspects such as nanoscale variations in superfluid densities or the order parameter symmetry of superconductors. However, experimental tools that offer quantitative, nanoscale magnetometry and operate over large ranges of temperature and magnetic fields are still lacking. Here, we demonstrate the first operation of a cryogenic scanning quantum sensor in the form of a single nitrogen-vacancy electronic spin in diamond, which is capable of overcoming these existing limitations. To demonstrate the power of our approach, we perform quantitative, nanoscale magnetic imaging of Pearl vortices in the cuprate superconductor YBa2Cu3O7-δ. With a sensor-to-sample distance of ∼10 nm, we observe striking deviations from the prevalent monopole approximation in our vortex stray-field images, and find excellent quantitative agreement with Pearl's analytic model. Our experiments provide a non-invasive and unambiguous determination of the system's local penetration depth and are readily extended to higher temperatures and magnetic fields. These results demonstrate the potential of quantitative quantum sensors in benchmarking microscopic models of complex electronic systems and open the door for further exploration of strongly correlated electron physics using scanning nitrogen-vacancy magnetometry.
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Affiliation(s)
- L Thiel
- Department of Physics, University of Basel, Klingelbergstrasse 82, Basel CH-4056, Switzerland
| | - D Rohner
- Department of Physics, University of Basel, Klingelbergstrasse 82, Basel CH-4056, Switzerland
| | - M Ganzhorn
- Department of Physics, University of Basel, Klingelbergstrasse 82, Basel CH-4056, Switzerland
| | - P Appel
- Department of Physics, University of Basel, Klingelbergstrasse 82, Basel CH-4056, Switzerland
| | - E Neu
- Department of Physics, University of Basel, Klingelbergstrasse 82, Basel CH-4056, Switzerland
| | - B Müller
- Physikalisches Institut and Center for Quantum Science (CQ) in LISA+, Universität Tübingen, Auf der Morgenstelle 14, D-72076 Tübingen, Germany
| | - R Kleiner
- Physikalisches Institut and Center for Quantum Science (CQ) in LISA+, Universität Tübingen, Auf der Morgenstelle 14, D-72076 Tübingen, Germany
| | - D Koelle
- Physikalisches Institut and Center for Quantum Science (CQ) in LISA+, Universität Tübingen, Auf der Morgenstelle 14, D-72076 Tübingen, Germany
| | - P Maletinsky
- Department of Physics, University of Basel, Klingelbergstrasse 82, Basel CH-4056, Switzerland
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14
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Wrachtrup J, Finkler A. Single spin magnetic resonance. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2016; 269:225-236. [PMID: 27378060 DOI: 10.1016/j.jmr.2016.06.017] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Revised: 06/22/2016] [Accepted: 06/25/2016] [Indexed: 06/06/2023]
Abstract
Different approaches have improved the sensitivity of either electron or nuclear magnetic resonance to the single spin level. For optical detection it has essentially become routine to observe a single electron spin or nuclear spin. Typically, the systems in use are carefully designed to allow for single spin detection and manipulation, and of those systems, diamond spin defects rank very high, being so robust that they can be addressed, read out and coherently controlled even under ambient conditions and in a versatile set of nanostructures. This renders them as a new type of sensor, which has been shown to detect single electron and nuclear spins among other quantities like force, pressure and temperature. Adapting pulse sequences from classic NMR and EPR, and combined with high resolution optical microscopy, proximity to the target sample and nanoscale size, the diamond sensors have the potential to constitute a new class of magnetic resonance detectors with single spin sensitivity. As diamond sensors can be operated under ambient conditions, they offer potential application across a multitude of disciplines. Here we review the different existing techniques for magnetic resonance, with a focus on diamond defect spin sensors, showing their potential as versatile sensors for ultra-sensitive magnetic resonance with nanoscale spatial resolution.
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Affiliation(s)
- Jörg Wrachtrup
- 3. Physikalisches Institut, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany; Max Planck Institute for Solid State Research, Heisenbergstr. 1, 70569 Stuttgart, Germany.
| | - Amit Finkler
- 3. Physikalisches Institut, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany.
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15
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Current-induced SQUID behavior of superconducting Nb nano-rings. Sci Rep 2016; 6:28320. [PMID: 27321733 PMCID: PMC4913244 DOI: 10.1038/srep28320] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Accepted: 05/31/2016] [Indexed: 11/30/2022] Open
Abstract
The critical temperature in a superconducting ring changes periodically with the magnetic flux threading it, giving rise to the well-known Little-Parks magnetoresistance oscillations. Periodic changes of the critical current in a superconducting quantum interference device (SQUID), consisting of two Josephson junctions in a ring, lead to a different type of magnetoresistance oscillations utilized in detecting extremely small changes in magnetic fields. Here we demonstrate current-induced switching between Little-Parks and SQUID magnetoresistance oscillations in a superconducting nano-ring without Josephson junctions. Our measurements in Nb nano-rings show that as the bias current increases, the parabolic Little-Parks magnetoresistance oscillations become sinusoidal and eventually transform into oscillations typical of a SQUID. We associate this phenomenon with the flux-induced non-uniformity of the order parameter along a superconducting nano-ring, arising from the superconducting leads (‘arms’) attached to it. Current enhanced phase slip rates at the points with minimal order parameter create effective Josephson junctions in the ring, switching it into a SQUID.
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Kremen A, Wissberg S, Haham N, Persky E, Frenkel Y, Kalisky B. Mechanical Control of Individual Superconducting Vortices. NANO LETTERS 2016; 16:1626-30. [PMID: 26836018 PMCID: PMC4789753 DOI: 10.1021/acs.nanolett.5b04444] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2015] [Revised: 01/15/2016] [Indexed: 05/25/2023]
Abstract
Manipulating individual vortices in a deterministic way is challenging; ideally, manipulation should be effective, local, and tunable in strength and location. Here, we show that vortices respond to local mechanical stress applied in the vicinity of the vortex. We utilized this interaction to move individual vortices in thin superconducting films via local mechanical contact without magnetic field or current. We used a scanning superconducting quantum interference device to image vortices and to apply local vertical stress with the tip of our sensor. Vortices were attracted to the contact point, relocated, and were stable at their new location. We show that vortices move only after contact and that more effective manipulation is achieved with stronger force and longer contact time. Mechanical manipulation of vortices provides a local view of the interaction between strain and nanomagnetic objects as well as controllable, effective, and reproducible manipulation technique.
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Affiliation(s)
- Anna Kremen
- Department
of Physics and Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat-Gan 5290002, Israel
| | - Shai Wissberg
- Department
of Physics and Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat-Gan 5290002, Israel
| | - Noam Haham
- Department
of Physics and Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat-Gan 5290002, Israel
| | - Eylon Persky
- Department
of Physics and Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat-Gan 5290002, Israel
| | - Yiftach Frenkel
- Department
of Physics and Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat-Gan 5290002, Israel
| | - Beena Kalisky
- Department
of Physics and Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat-Gan 5290002, Israel
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