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Turkin YV, Pugach N. Spin dynamics in superconductor/ferromagnetic insulator hybrid structures with precessing magnetization. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2023; 14:233-239. [PMID: 36865092 PMCID: PMC9972883 DOI: 10.3762/bjnano.14.22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Accepted: 02/06/2023] [Indexed: 06/18/2023]
Abstract
The main goal of the present work is the description of the dynamics of spin current and induced magnetization inside a superconducting film S that is in contact with a ferromagnetic insulator layer FI. Spin current and induced magnetization are calculated not only at the interface of the S/FI hybrid structure, but also inside the superconducting film. The new and interesting predicted effect is the frequency dependence of the induced magnetization with a maximum appearing at high temperatures. It is also shown that the increase of the magnetization precession frequency can drastically change the spin distribution of quasiparticles at the S/FI interface.
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Affiliation(s)
- Yaroslav V Turkin
- HSE University, Moscow 101000, Russia
- Vernadsky Crimean Federal University, Simferopol 295007
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Yao Y, Cai R, Yu T, Ma Y, Xing W, Ji Y, Xie XC, Yang SH, Han W. Giant oscillatory Gilbert damping in superconductor/ferromagnet/superconductor junctions. SCIENCE ADVANCES 2021; 7:eabh3686. [PMID: 34826245 PMCID: PMC8626077 DOI: 10.1126/sciadv.abh3686] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Accepted: 10/06/2021] [Indexed: 06/13/2023]
Abstract
Interfaces between materials with differently ordered phases present unique opportunities for exotic physical properties, especially the interplay between ferromagnetism and superconductivity in the ferromagnet/superconductor heterostructures. The investigation of zero- and π-junctions has been of particular interest for both fundamental physical science and emerging technologies. Here, we report the experimental observation of giant oscillatory Gilbert damping in the superconducting niobium/nickel-iron/niobium junctions with respect to the nickel-iron thickness. This observation suggests an unconventional spin pumping and relaxation via zero-energy Andreev bound states that exist not only in the niobium/nickel-iron/niobium π-junctions but also in the niobium/nickel-iron/niobium zero-junctions. Our findings could be important for further exploring the exotic physical properties of ferromagnet/superconductor heterostructures and potential applications of ferromagnet π-junctions in quantum computing, such as half-quantum flux qubits.
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Affiliation(s)
- Yunyan Yao
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, China
| | - Ranran Cai
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, China
| | - Tao Yu
- Max Planck Institute for the Structure and Dynamics of Matter, 22761 Hamburg, Germany
| | - Yang Ma
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, China
| | - Wenyu Xing
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, China
| | - Yuan Ji
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, China
| | - Xin-Cheng Xie
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, China
- CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing 100190, China
- Beijing Academy of Quantum Information Sciences, Beijing 100193, China
| | | | - Wei Han
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, China
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Bobkova IV, Bobkov AM, Silaev MA. Dynamic Spin-Triplet Order Induced by Alternating Electric Fields in Superconductor-Ferromagnet-Superconductor Josephson Junctions. PHYSICAL REVIEW LETTERS 2021; 127:147701. [PMID: 34652200 DOI: 10.1103/physrevlett.127.147701] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2021] [Accepted: 09/01/2021] [Indexed: 06/13/2023]
Abstract
Dynamic states offer extended possibilities to control the properties of quantum matter. Recent efforts are focused on studying the ordered states which appear exclusively under the time-dependent drives. Here, we demonstrate a class of systems which feature dynamic spin-triplet superconducting order stimulated by the alternating electric field. The effect is based on the interplay of ferromagnetism, interfacial spin-orbital coupling, and the condensate motion driven by the field, which converts hidden static p-wave order, produced by the joint action of the ferromagnetism and the spin-orbital coupling, into dynamic s-wave equal-spin-triplet correlations. We demonstrate that the critical current of Josephson junctions hosting these states is proportional to the electromagnetic power, supplied either by the external irradiation or by the ac current source. Based on these unusual properties we propose the scheme of a Josephson transistor which can be switched by the ac voltage and demonstrates an even-numbered sequence of Shapiro steps. Combining the photoactive Josephson junctions with recently discovered Josephson phase batteries we find photomagnetic SQUID devices which can generate spontaneous magnetic fields while being exposed to irradiation.
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Affiliation(s)
- I V Bobkova
- Institute of Solid State Physics, Chernogolovka, Moscow region, 142432 Russia
- Moscow Institute of Physics and Technology, Dolgoprudny 141700, Russia
- National Research University Higher School of Economics, Moscow 101000, Russia
| | - A M Bobkov
- Institute of Solid State Physics, Chernogolovka, Moscow region, 142432 Russia
| | - M A Silaev
- Moscow Institute of Physics and Technology, Dolgoprudny 141700, Russia
- Department of Physics, Nanoscience Center, University of Jyväskylä, 40014 Jyväskylä, Finland
- Institute for Physics of Microstructures, Russian Academy of Sciences, 603950 Nizhny Novgorod, GSP-105, Russia
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Controlling spin supercurrents via nonequilibrium spin injection. Sci Rep 2019; 9:12731. [PMID: 31519921 PMCID: PMC6744513 DOI: 10.1038/s41598-019-48945-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Accepted: 07/17/2019] [Indexed: 11/22/2022] Open
Abstract
We propose a mechanism whereby spin supercurrents can be manipulated in superconductor/ferromagnet proximity systems via nonequilibrium spin injection. We find that if a spin supercurrent exists in equilibrium, a nonequilibrium spin accumulation will exert a torque on the spins transported by this current. This interaction causes a new spin supercurrent contribution to manifest out of equilibrium, which is proportional to and polarized perpendicularly to both the injected spins and the equilibrium spin current. This is interesting for several reasons: as a fundamental physical effect; due to possible applications as a way to control spin supercurrents; and timeliness in light of recent experiments on spin injection in proximitized superconductors.
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Holmqvist C, Belzig W, Fogelström M. Non-equilibrium charge and spin transport in superconducting-ferromagnetic-superconducting point contacts. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2018; 376:20150229. [PMID: 29941627 PMCID: PMC6030142 DOI: 10.1098/rsta.2015.0229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 04/16/2016] [Indexed: 06/08/2023]
Abstract
The conventional Josephson effect may be modified by introducing spin-active scattering in the interface layer of the junction. Here, we discuss a Josephson junction consisting of two s-wave superconducting leads coupled over a classical spin that precesses with the Larmor frequency due to an external magnetic field. This magnetically active interface results in a time-dependent boundary condition with different tunnelling amplitudes for spin-up and -down quasi-particles and where the precession produces spin-flip scattering processes. As a result, the Andreev states develop sidebands and a non-equilibrium population that depend on the details of the spin precession. The Andreev states carry a steady-state Josephson charge current and a time-dependent spin current, whose current-phase relations could be used to characterize the precessing spin. The spin current is supported by spin-triplet correlations induced by the spin precession and creates a feedback effect on the classical spin in the form of a torque that shifts the precession frequency. By applying a bias voltage, the Josephson frequency adds another complexity to the situation and may create resonances together with the Larmor frequency. These Shapiro resonances manifest as torques and, under suitable conditions, are able to reverse the direction of the classical spin in sub-nanosecond time. Another characteristic feature is the subharmonic gap structure in the DC charge current displaying an even-odd effect attributable to precession-assisted multiple Andreev reflections.This article is part of the theme issue 'Andreev bound states'.
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Affiliation(s)
- C Holmqvist
- Department of Physics, Norwegian University of Science and Technology, 7491 Trondheim, Norway
| | - W Belzig
- Fachbereich Physik, Universität Konstanz, 78457 Konstanz, Germany
| | - M Fogelström
- Department of Microtechnology and Nanoscience - MC2, Chalmers University of Technology, 412 96 Göteborg, Sweden
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Jeon KR, Ciccarelli C, Ferguson AJ, Kurebayashi H, Cohen LF, Montiel X, Eschrig M, Robinson JWA, Blamire MG. Enhanced spin pumping into superconductors provides evidence for superconducting pure spin currents. NATURE MATERIALS 2018; 17:499-503. [PMID: 29662156 DOI: 10.1038/s41563-018-0058-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 03/13/2018] [Indexed: 06/08/2023]
Abstract
Unlike conventional spin-singlet Cooper pairs, spin-triplet pairs can carry spin1,2. Triplet supercurrents were discovered in Josephson junctions with metallic ferromagnet spacers, where spin transport can occur only within the ferromagnet and in conjunction with a charge current. Ferromagnetic resonance injects a pure spin current from a precessing ferromagnet into adjacent non-magnetic materials3,4. For spin-singlet pairing, the ferromagnetic resonance spin pumping efficiency decreases below the critical temperature (Tc) of a coupled superconductor5,6. Here we present ferromagnetic resonance experiments in which spin sink layers with strong spin-orbit coupling are added to the superconductor. Our results show that the induced spin currents, rather than being suppressed, are substantially larger in the superconducting state compared with the normal state; although further work is required to establish the details of the spin transport process, we show that this cannot be mediated by quasiparticles and is most likely a triplet pure spin supercurrent.
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Affiliation(s)
- Kun-Rok Jeon
- Department of Materials Science and Metallurgy, University of Cambridge, Cambridge, UK
- Cavendish Laboratory, University of Cambridge, Cambridge, UK
| | | | | | - Hidekazu Kurebayashi
- London Centre for Nanotechnology and Department of Electronic and Electrical Engineering at University of College London, London, UK
| | - Lesley F Cohen
- The Blackett Laboratory, Imperial College London, London, UK
| | - Xavier Montiel
- Department of Physics, Royal Holloway, University of London, Egham, UK
| | - Matthias Eschrig
- Department of Physics, Royal Holloway, University of London, Egham, UK
| | - Jason W A Robinson
- Department of Materials Science and Metallurgy, University of Cambridge, Cambridge, UK
| | - Mark G Blamire
- Department of Materials Science and Metallurgy, University of Cambridge, Cambridge, UK.
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Eschrig M. Spin-polarized supercurrents for spintronics: a review of current progress. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2015; 78:104501. [PMID: 26397456 DOI: 10.1088/0034-4885/78/10/104501] [Citation(s) in RCA: 77] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
During the past 15 years a new field has emerged, which combines superconductivity and spintronics, with the goal to pave a way for new types of devices for applications combining the virtues of both by offering the possibility of long-range spin-polarized supercurrents. Such supercurrents constitute a fruitful basis for the study of fundamental physics as they combine macroscopic quantum coherence with microscopic exchange interactions, spin selectivity, and spin transport. This report follows recent developments in the controlled creation of long-range equal-spin triplet supercurrents in ferromagnets and its contribution to spintronics. The mutual proximity-induced modification of order in superconductor-ferromagnet hybrid structures introduces in a natural way such evasive phenomena as triplet superconductivity, odd-frequency pairing, Fulde-Ferrell-Larkin-Ovchinnikov pairing, long-range equal-spin supercurrents, [Formula: see text]-Josephson junctions, as well as long-range magnetic proximity effects. All these effects were rather exotic before 2000, when improvements in nanofabrication and materials control allowed for a new quality of hybrid structures. Guided by pioneering theoretical studies, experimental progress evolved rapidly, and since 2010 triplet supercurrents are routinely produced and observed. We have entered a new stage of studying new phases of matter previously out of our reach, and of merging the hitherto disparate fields of superconductivity and spintronics to a new research direction: super-spintronics.
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Affiliation(s)
- Matthias Eschrig
- Department of Physics, Royal Holloway, University of London, Egham Hill, Egham, Surrey TW20 0EX, UK
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Mori M, Koshibae W, Hikino SI, Maekawa S. Possible method to observe the breathing mode of a magnetic domain wall in the Josephson junction. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2014; 26:255702. [PMID: 24888471 DOI: 10.1088/0953-8984/26/25/255702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
A magnetic domain wall (DW) behaves as a massive particle with elasticity. Sliding and oscillation of the DW have been observed experimentally, whereas vibration of a width in the DW, "breathing mode", has not been measured so far. We theoretically propose how to observe the breathing mode by the Josephson junction having a ferromagnetic layer between superconducting electrodes. The current-voltage (I-V) curve is calculated by an equivalent circuit of the resistively shunted junction model. The breathing mode is identified by stepwise structures in the I-V curve, which appear at the voltages V = n (ħ/2e)ω with the fundamental constant ħ/e, integer number n and the frequency of the breathing mode ω.
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Abouie J, Abdollahipour B, Rostami AA. Spin nutation effects in molecular nanomagnet-superconductor tunnel junctions. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2013; 25:465701. [PMID: 24129308 DOI: 10.1088/0953-8984/25/46/465701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
We study the spin nutation effects of a molecular nanomagnet on the Josephson current through a superconductor|molecular nanomagnet|superconductor tunnel junction. We explicitly demonstrate that, due to the spin nutation of the molecular nanomagnet, two oscillatory terms emerge in the ac Josephson current in addition to the conventional ac Josephson current. Some resonances occur in the junction due to the interactions of the transported quasiparticles with the bias voltage and molecular nanomagnet spin dynamics. Their appearance indicates that the energy exchanged during these interactions is in the range of the superconducting energy gap. We also show that the spin nutation is able to convert the ac Josephson current to a dc current, which is interesting for applications.
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Affiliation(s)
- J Abouie
- Department of Physics, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan 45137-66731, Iran. School of Physics, Institute for Research in Fundamental Sciences (IPM), Tehran 19395-5531, Iran
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Linder J, Brataas A, Shomali Z, Zareyan M. Spin-transfer and exchange torques in ferromagnetic superconductors. PHYSICAL REVIEW LETTERS 2012; 109:237206. [PMID: 23368259 DOI: 10.1103/physrevlett.109.237206] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2012] [Indexed: 06/01/2023]
Abstract
We consider how superconducting correlations influence spin-transfer torques in ferromagnetic superconductors. It is demonstrated that there is a novel torque arising from particle-hole interference that depends on the U(1) phase associated with the superconducting order parameter. We also show that there is an equilibrium exchange torque between two ferromagnetic superconductors in contact via a normal metal mediated by Andreev states. The latter equilibrium magnetic torque is also sensitive to spin-resolved phase differences in the superconducting order parameters as well as to an externally applied phase difference.
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Affiliation(s)
- Jacob Linder
- Department of Physics, Norwegian University of Science and Technology, N-7491 Trondheim, Norway
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Richard C, Houzet M, Meyer JS. Andreev current induced by ferromagnetic resonance. PHYSICAL REVIEW LETTERS 2012; 109:057002. [PMID: 23006200 DOI: 10.1103/physrevlett.109.057002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2012] [Indexed: 06/01/2023]
Abstract
We study charge transport through a metallic dot coupled to a superconducting and a ferromagnetic lead with a precessing magnetization due to ferromagnetic resonance. Using the quasiclassical theory, we find that the magnetization precession induces a dc current in the subgap regime even in the absence of a bias voltage. This effect is due to the rectification of the ac spin currents at the interface with the ferromagnet; it exists in the absence of spin current in the superconductor. When the dot is strongly coupled to the superconductor, we find a strong enhancement in a wide range of parameters as compared to the induced current in the normal state.
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Volkov AF, Efetov KB. Hybridization of spin and plasma waves in Josephson tunnel junctions containing a ferromagnetic layer. PHYSICAL REVIEW LETTERS 2009; 103:037003. [PMID: 19659309 DOI: 10.1103/physrevlett.103.037003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2008] [Indexed: 05/28/2023]
Abstract
We study dynamics of tunnel Josephson junctions with a thin ferromagnetic layer F [superconductor-insulator-ferromagnet-superconductor (SIFS) junctions]. On the basis of derived equations relating the superconducting phase and magnetic moment to each other we analyze collective excitations in the system and find a new mode which is a hybrid of plasmalike and spin waves. The latter are coupled together in a broad range of parameters characterizing the system. Using the solution describing the collective modes we demonstrate that besides the Fiske steps new peaks appear on the I-V characteristics due to oscillations of the magnetic moment M in the ferromagnetic layer. Thus, by measuring the I-V curve of the SIFS junctions, one can extract information about the spectrum of spin excitations in the ferromagnet F.
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Affiliation(s)
- A F Volkov
- Theoretische Physik III, Ruhr-Universität Bochum, D-44780 Bochum, Germany
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Konschelle F, Buzdin A. Magnetic moment manipulation by a Josephson current. PHYSICAL REVIEW LETTERS 2009; 102:017001. [PMID: 19257227 DOI: 10.1103/physrevlett.102.017001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2008] [Indexed: 05/27/2023]
Abstract
We consider a Josephson junction where the weak link is formed by a noncentrosymmetric ferromagnet. In such a junction, the superconducting current acts as a direct driving force on the magnetic moment. We show that the ac Josephson effect generates a magnetic precession providing then a feedback to the current. Magnetic dynamics result in several anomalies of current-phase relations (second harmonic, dissipative current) which are strongly enhanced near the ferromagnetic resonance frequency.
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Affiliation(s)
- F Konschelle
- Condensed Matter Theory Group, CPMOH, Université de Bordeaux and CNRS, F-33405 Talence, France
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