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Bhatia E, Srivastava A, Devine-Stoneman J, Stelmashenko NA, Barber ZH, Robinson JWA, Senapati K. Nanoscale Domain Wall Engineered Spin-Triplet Josephson Junctions and SQUID. NANO LETTERS 2021; 21:3092-3097. [PMID: 33724857 DOI: 10.1021/acs.nanolett.1c00273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Spin-singlet Cooper pairs convert to spin-triplet Cooper pairs on passing through a magnetically noncollinear structure at a superconductor(S)/ferromagnet(F) interface. In this context, the generation of triplet supercurrents through intrinsic ferromagnetic domain walls, which are naturally occurring noncollinear magnetic features, was proposed theoretically in the past decade. However, an experimental demonstration has been lacking in the literature, particularly because of the difficulty in accessing a single domain wall, which is typically buried between two domains in a ferromagnetic material. By patterning a ferromagnetic nanoconstriction, we have been able to realize a nanoscale S/F/S planar junction, where a single domain wall (pinned at the nanoconstriction) acts as a Josephson barrier. In this geometry, we are able to show the predicted long-range triplet supercurrent across a ferromagnetic barrier exceeding 70 nm. Using this technique, we have demonstrated a ferromagnetic planar nano-SQUID device consisting of two Nb/Ni/Nb spin-triplet Josephson junctions.
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Affiliation(s)
- Ekta Bhatia
- School of Physical Sciences, National Institute of Science Education and Research (NISER), HBNI, Bhubaneswar, Odisha 752050, India
| | - Anand Srivastava
- Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS, United Kingdom
| | - James Devine-Stoneman
- Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS, United Kingdom
| | - Nadia A Stelmashenko
- Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS, United Kingdom
| | - Zoe H Barber
- Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS, United Kingdom
| | - Jason W A Robinson
- Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS, United Kingdom
| | - Kartik Senapati
- School of Physical Sciences, National Institute of Science Education and Research (NISER), HBNI, Bhubaneswar, Odisha 752050, India
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Zhang S, Zhang X, Zhang J, Ganguly A, Xia J, Wen Y, Zhang Q, Yu G, Hou Z, Wang W, Peng Y, Xiao G, Manchon A, Kosel J, Zhou Y, Zhang XX. Direct imaging of an inhomogeneous electric current distribution using the trajectory of magnetic half-skyrmions. SCIENCE ADVANCES 2020; 6:eaay1876. [PMID: 32083177 PMCID: PMC7007247 DOI: 10.1126/sciadv.aay1876] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Accepted: 11/22/2019] [Indexed: 05/25/2023]
Abstract
The direct imaging of current density vector distributions in thin films has remained a daring challenge. Here, we report that an inhomogeneous current distribution can be mapped directly by the trajectories of magnetic half-skyrmions driven by an electrical current in Pt/Co/Ta trilayer, using polar magneto-optical Kerr microscopy. The half-skyrmion carries a topological charge of 0.5 due to the presence of Dzyaloshinskii-Moriya interaction, which leads to the half-skyrmion Hall effect. The Hall angle of half-skyrmions is independent of current density and can be reduced to as small as 4° by tuning the thickness of the Co layer. The Hall angle is so small that the elongation path of half-skyrmion approximately delineates the invisible current flow as demonstrated in both a continuous film and a curved track. Our work provides a practical technique to directly map inhomogeneous current distribution even in complex geometries for both fundamental research and industrial applications.
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Affiliation(s)
- Senfu Zhang
- Physical Science and Engineering Division (PSE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
| | - Xichao Zhang
- School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, Guangdong 518172, China
| | - Junwei Zhang
- Physical Science and Engineering Division (PSE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
- Key Laboratory for Magnetism and Magnetic Materials of the Ministry of Education, Lanzhou University, Lanzhou 730000, China
| | - Arnab Ganguly
- Physical Science and Engineering Division (PSE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
| | - Jing Xia
- School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, Guangdong 518172, China
| | - Yan Wen
- Physical Science and Engineering Division (PSE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
| | - Qiang Zhang
- Physical Science and Engineering Division (PSE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
| | - Guoqiang Yu
- State Key Laboratory of Magnetism, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Zhipeng Hou
- Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials and Institute for Advanced Materials, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou 510006, China
| | - Wenhong Wang
- State Key Laboratory of Magnetism, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Yong Peng
- Key Laboratory for Magnetism and Magnetic Materials of the Ministry of Education, Lanzhou University, Lanzhou 730000, China
| | - Gang Xiao
- Department of Physics, Brown University, Providence, RI 02912, USA
| | - Aurelien Manchon
- Physical Science and Engineering Division (PSE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
| | - Jürgen Kosel
- Computer, Electrical and Mathematical Sciences and Engineering Division, KAUST, Thuwal 23955-6900, Saudi Arabia
| | - Yan Zhou
- School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, Guangdong 518172, China
| | - Xi-Xiang Zhang
- Physical Science and Engineering Division (PSE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
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Kageura T, Hideko M, Tsuyuzaki I, Morishita A, Kawano A, Sasama Y, Yamaguchi T, Takano Y, Tachiki M, Ooi S, Hirata K, Arisawa S, Kawarada H. Single-crystalline boron-doped diamond superconducting quantum interference devices with regrowth-induced step edge structure. Sci Rep 2019; 9:15214. [PMID: 31645621 PMCID: PMC6811626 DOI: 10.1038/s41598-019-51596-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Accepted: 09/26/2019] [Indexed: 11/21/2022] Open
Abstract
Superconducting quantum interference devices (SQUIDs) are currently used as magnetic flux detectors with ultra-high sensitivity for various applications such as medical diagnostics and magnetic material microstructure analysis. Single-crystalline superconducting boron-doped diamond is an excellent candidate for fabricating high-performance SQUIDs because of its robustness and high transition temperature, critical current density, and critical field. Here, we propose a fabrication process for a single-crystalline boron-doped diamond Josephson junction with regrowth-induced step edge structure and demonstrate the first operation of a single-crystalline boron-doped diamond SQUID above 2 K. We demonstrate that the step angle is a significant parameter for forming the Josephson junction and that the step angle can be controlled by adjusting the microwave plasma-enhanced chemical vapour deposition conditions of the regrowth layer. The fabricated junction exhibits superconductor-weak superconductor-superconductor-type behaviour without hysteresis and a high critical current density of 5800 A/cm2.
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Affiliation(s)
- Taisuke Kageura
- Faculty of Science & Engineering, Waseda University, 3-4-1, Okubo, Shinjuku-ku, Tokyo, 169-8555, Japan.
| | - Masakuni Hideko
- Faculty of Science & Engineering, Waseda University, 3-4-1, Okubo, Shinjuku-ku, Tokyo, 169-8555, Japan
| | - Ikuto Tsuyuzaki
- Faculty of Science & Engineering, Waseda University, 3-4-1, Okubo, Shinjuku-ku, Tokyo, 169-8555, Japan
| | - Aoi Morishita
- Faculty of Science & Engineering, Waseda University, 3-4-1, Okubo, Shinjuku-ku, Tokyo, 169-8555, Japan
| | - Akihiro Kawano
- Faculty of Science & Engineering, Waseda University, 3-4-1, Okubo, Shinjuku-ku, Tokyo, 169-8555, Japan
| | - Yosuke Sasama
- National Institute for Materials Science, 1-2-1, Sengen, Tsukuba, Ibaraki, 305-0047, Japan
| | - Takahide Yamaguchi
- National Institute for Materials Science, 1-2-1, Sengen, Tsukuba, Ibaraki, 305-0047, Japan
| | - Yoshihiko Takano
- National Institute for Materials Science, 1-2-1, Sengen, Tsukuba, Ibaraki, 305-0047, Japan
| | - Minoru Tachiki
- National Institute for Materials Science, 1-2-1, Sengen, Tsukuba, Ibaraki, 305-0047, Japan
| | - Shuuichi Ooi
- National Institute for Materials Science, 1-2-1, Sengen, Tsukuba, Ibaraki, 305-0047, Japan
| | - Kazuto Hirata
- National Institute for Materials Science, 1-2-1, Sengen, Tsukuba, Ibaraki, 305-0047, Japan
| | - Shunichi Arisawa
- National Institute for Materials Science, 1-2-1, Sengen, Tsukuba, Ibaraki, 305-0047, Japan
| | - Hiroshi Kawarada
- Faculty of Science & Engineering, Waseda University, 3-4-1, Okubo, Shinjuku-ku, Tokyo, 169-8555, Japan.
- The Kagami Memorial Laboratory for Materials Science and Technology, Waseda University, 2-8-26, Nishiwaseda, Shinjuku-ku, Tokyo, 169-0051, Japan.
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Pan YP, Wang SY, Liu XY, Lin YS, Ma LX, Feng Y, Wang Z, Chen L, Wang YH. 3D nano-bridge-based SQUID susceptometers for scanning magnetic imaging of quantum materials. NANOTECHNOLOGY 2019; 30:305303. [PMID: 30965292 DOI: 10.1088/1361-6528/ab1792] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
We designed and fabricated a new type of superconducting quantum interference device (SQUID) susceptometers for magnetic imaging of quantum materials. The 2-junction SQUID sensors employ 3D Nb nano-bridges fabricated using electron-beam lithography. The two counter-wound balanced pickup loops of the SQUID enable gradiometric measurement and they are surrounded by a one-turn field coil for susceptibility measurements. The smallest pickup loop of the SQUIDs were 1 μm in diameter and the flux noise was around 1 μФ0/√Hz at 100 Hz. We demonstrate scanning magnetometry, susceptometry and current magnetometry on some test samples using these nano-SQUIDs.
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Affiliation(s)
- Y P Pan
- Department of Physics and State Key Laboratory of Surface Physics, Fudan University, Shanghai 200438 People's Republic of China. Center for Excellence in Superconducting Electronics, State Key Laboratory of Functional Material for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050 People's Republic of China
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Chang K, Eichler A, Rhensius J, Lorenzelli L, Degen CL. Nanoscale Imaging of Current Density with a Single-Spin Magnetometer. NANO LETTERS 2017; 17:2367-2373. [PMID: 28329445 DOI: 10.1021/acs.nanolett.6b05304] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Charge transport in nanostructures and thin films is fundamental to many phenomena and processes in science and technology, ranging from quantum effects and electronic correlations in mesoscopic physics, to integrated charge- or spin-based electronic circuits, to photoactive layers in energy research. Direct visualization of the charge flow in such structures is challenging due to their nanometer size and the itinerant nature of currents. In this work, we demonstrate noninvasive magnetic imaging of current density in two-dimensional conductor networks including metallic nanowires and carbon nanotubes. Our sensor is the electronic spin of a diamond nitrogen-vacancy center attached to a scanning tip and operated under ambient conditions. Using a differential measurement technique, we detect DC currents down to a few μA with a current density noise floor of ∼2 × 104 A/cm2. Reconstructed images have a spatial resolution of typically 50 nm, with a best-effort value of 22 nm. Current density imaging offers a new route for studying electronic transport and conductance variations in two-dimensional materials and devices, with many exciting applications in condensed matter physics and materials science.
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Affiliation(s)
- K Chang
- Department of Physics, ETH Zurich , Otto Stern Weg 1, 8093 Zurich, Switzerland
| | - A Eichler
- Department of Physics, ETH Zurich , Otto Stern Weg 1, 8093 Zurich, Switzerland
| | - J Rhensius
- Department of Physics, ETH Zurich , Otto Stern Weg 1, 8093 Zurich, Switzerland
| | - L Lorenzelli
- Department of Physics, ETH Zurich , Otto Stern Weg 1, 8093 Zurich, Switzerland
| | - C L Degen
- Department of Physics, ETH Zurich , Otto Stern Weg 1, 8093 Zurich, Switzerland
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Meissner effect measurement of single indium particle using a customized on-chip nano-scale superconducting quantum interference device system. Sci Rep 2017; 7:45945. [PMID: 28374779 PMCID: PMC5379673 DOI: 10.1038/srep45945] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Accepted: 03/07/2017] [Indexed: 11/09/2022] Open
Abstract
As many emergent phenomena of superconductivity appear on a smaller scale and at lower dimension, commercial magnetic property measurement systems (MPMSs) no longer provide the sensitivity necessary to study the Meissner effect of small superconductors. The nano-scale superconducting quantum interference device (nano-SQUID) is considered one of the most sensitive magnetic sensors for the magnetic characterization of mesoscopic or microscopic samples. Here, we develop a customized on-chip nano-SQUID measurement system based on a pulsed current biasing method. The noise performance of our system is approximately 4.6 × 10-17 emu/Hz1/2, representing an improvement of 9 orders of magnitude compared with that of a commercial MPMS (~10-8 emu/Hz1/2). Furthermore, we demonstrate the measurement of the Meissner effect of a single indium (In) particle (of 47 μm in diameter) using our on-chip nano-SQUID system. The system enables the observation of the prompt superconducting transition of the Meissner effect of a single In particle, thereby providing more accurate characterization of the critical field Hc and temperature Tc. In addition, the retrapping field Hre as a function of temperature T of single In particle shows disparate behavior from that of a large ensemble.
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Martínez-Pérez MJ, Gella D, Müller B, Morosh V, Wölbing R, Sesé J, Kieler O, Kleiner R, Koelle D. Three-Axis Vector Nano Superconducting Quantum Interference Device. ACS NANO 2016; 10:8308-8315. [PMID: 27332709 DOI: 10.1021/acsnano.6b02218] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We present the design, realization, and performance of a three-axis vector nano superconducting quantum interference device (nanoSQUID). It consists of three mutually orthogonal SQUID nanoloops that allow distinguishing the three components of the vector magnetic moment of individual nanoparticles placed at a specific position. The device is based on Nb/HfTi/Nb Josephson junctions and exhibits line widths of ∼250 nm and inner loop areas of 600 × 90 and 500 × 500 nm(2). Operation at temperature T = 4.2 K under external magnetic fields perpendicular to the substrate plane up to ∼50 mT is demonstrated. The experimental flux noise below [Formula: see text] in the white noise limit and the reduced dimensions lead to a total calculated spin sensitivity of [Formula: see text] and [Formula: see text] for the in-plane and out-of-plane components of the vector magnetic moment, respectively. The potential of the device for studying three-dimensional properties of individual nanomagnets is discussed.
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Affiliation(s)
- María José Martínez-Pérez
- Physikalisches Institut-Experimentalphysik II and Center for Quantum Science (CQ) in LISA+, Universität Tübingen , Auf der Morgenstelle 14, D-72076 Tübingen, Germany
| | - Diego Gella
- Physikalisches Institut-Experimentalphysik II and Center for Quantum Science (CQ) in LISA+, Universität Tübingen , Auf der Morgenstelle 14, D-72076 Tübingen, Germany
| | - Benedikt Müller
- Physikalisches Institut-Experimentalphysik II and Center for Quantum Science (CQ) in LISA+, Universität Tübingen , Auf der Morgenstelle 14, D-72076 Tübingen, Germany
| | - Viacheslav Morosh
- Fachbereich Quantenelektronik, Physikalisch-Technische Bundesanstalt , Bundesallee 100, D-38116 Braunschweig, Germany
| | - Roman Wölbing
- Physikalisches Institut-Experimentalphysik II and Center for Quantum Science (CQ) in LISA+, Universität Tübingen , Auf der Morgenstelle 14, D-72076 Tübingen, Germany
| | - Javier Sesé
- Laboratorio de Microscopías Avanzadas (LMA), Instituto de Nanociencia de Aragón (INA), Universidad de Zaragoza , E-50018 Zaragoza, Spain
| | - Oliver Kieler
- Fachbereich Quantenelektronik, Physikalisch-Technische Bundesanstalt , Bundesallee 100, D-38116 Braunschweig, Germany
| | - Reinhold Kleiner
- Physikalisches Institut-Experimentalphysik II and Center for Quantum Science (CQ) in LISA+, Universität Tübingen , Auf der Morgenstelle 14, D-72076 Tübingen, Germany
| | - Dieter Koelle
- Physikalisches Institut-Experimentalphysik II and Center for Quantum Science (CQ) in LISA+, Universität Tübingen , Auf der Morgenstelle 14, D-72076 Tübingen, Germany
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