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Samardak AS, Ognev AV, Kolesnikov AG, Stebliy ME, Samardak VY, Iliushin IG, Pervishko AA, Yudin D, Platunov M, Ono T, Wilhelm F, Rogalev A. XMCD and ab initio study of interface-engineered ultrathin Ru/Co/W/Ru films with perpendicular magnetic anisotropy and strong Dzyaloshinskii-Moriya interaction. Phys Chem Chem Phys 2022; 24:8225-8232. [PMID: 35319030 DOI: 10.1039/d1cp05456b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Understanding the nature of recently discovered spin-orbital induced phenomena and a definition of a general approach for "ferromagnet/heavy-metal" layered systems to enhance and manipulate spin-orbit coupling, spin-orbit torque, and the Dzyaloshinskii-Moriya interaction (DMI) assisted by atomic-scale interface engineering are essential for developing spintronics and spin-orbitronics. Here, we exploit X-ray magnetic circular dichroism (XMCD) spectroscopy at the L2,3-edges of 5d and 4d non-magnetic heavy metals (W and Ru, respectively) in ultrathin Ru/Co/W/Ru films to determine their induced magnetic moments due to the proximity to the ferromagnetic layer of Co. The deduced orbital and spin magnetic moments agree well with the theoretically predicted values, highlighting the drastic effect of constituting layers on the system's magnetic properties and the strong interfacial DMI in Ru/Co/W/Ru films. As a result, we demonstrate the ability to simultaneously control the strength of magnetic anisotropy and intermixing-enhanced DMI through the interface engineered inversion asymmetry in thin-film chiral ferromagnets, which are a potential host for stable magnetic skyrmions.
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Affiliation(s)
- Alexander S Samardak
- Institute of High Technologies and Advanced Materials, Far Eastern Federal University, 690922 Vladivostok, Russia.
| | - Alexey V Ognev
- Institute of High Technologies and Advanced Materials, Far Eastern Federal University, 690922 Vladivostok, Russia.
| | - Alexander G Kolesnikov
- Institute of High Technologies and Advanced Materials, Far Eastern Federal University, 690922 Vladivostok, Russia.
| | - Maksim E Stebliy
- Institute of High Technologies and Advanced Materials, Far Eastern Federal University, 690922 Vladivostok, Russia.
| | - Vadim Yu Samardak
- Institute of High Technologies and Advanced Materials, Far Eastern Federal University, 690922 Vladivostok, Russia.
| | - Ilia G Iliushin
- Institute of High Technologies and Advanced Materials, Far Eastern Federal University, 690922 Vladivostok, Russia.
| | | | - Dmitry Yudin
- Skolkovo Institute of Science and Technology, 121205 Moscow, Russia
| | - Mikhail Platunov
- Kirensky Institute of Physics, Federal Research Center KSC SB RAS, 660036 Krasnoyarsk, Russia.,Synchrotron radiation facility SKIF, Boreskov Institute of Catalysis SB RAS, 630559 Kol'tsovo, Russia.
| | - Teruo Ono
- Institute of High Technologies and Advanced Materials, Far Eastern Federal University, 690922 Vladivostok, Russia. .,Institute for Chemical Research, Kyoto University, Uji, Kyoto, Japan
| | - Fabrice Wilhelm
- ESRF-The European Synchrotron, 38043 Grenoble Cedex 9, France
| | - Andrey Rogalev
- ESRF-The European Synchrotron, 38043 Grenoble Cedex 9, France
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Zhang H, Raftrey D, Chan YT, Shao YT, Chen R, Chen X, Huang X, Reichanadter JT, Dong K, Susarla S, Caretta L, Chen Z, Yao J, Fischer P, Neaton JB, Wu W, Muller DA, Birgeneau RJ, Ramesh R. Room-temperature skyrmion lattice in a layered magnet (Fe 0.5Co 0.5) 5GeTe 2. Sci Adv 2022; 8:eabm7103. [PMID: 35319983 PMCID: PMC8942374 DOI: 10.1126/sciadv.abm7103] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Accepted: 01/28/2022] [Indexed: 05/26/2023]
Abstract
Novel magnetic ground states have been stabilized in two-dimensional (2D) magnets such as skyrmions, with the potential next-generation information technology. Here, we report the experimental observation of a Néel-type skyrmion lattice at room temperature in a single-phase, layered 2D magnet, specifically a 50% Co-doped Fe5GeTe2 (FCGT) system. The thickness-dependent magnetic domain size follows Kittel's law. The static spin textures and spin dynamics in FCGT nanoflakes were studied by Lorentz electron microscopy, variable-temperature magnetic force microscopy, micromagnetic simulations, and magnetotransport measurements. Current-induced skyrmion lattice motion was observed at room temperature, with a threshold current density, jth = 1 × 106 A/cm2. This discovery of a skyrmion lattice at room temperature in a noncentrosymmetric material opens the way for layered device applications and provides an ideal platform for studies of topological and quantum effects in 2D.
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Affiliation(s)
- Hongrui Zhang
- Department of Materials Science and Engineering, University of California, Berkeley, Berkeley, CA, USA
| | - David Raftrey
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Physics Department, University of California, Santa Cruz, Santa Cruz, CA, USA
| | - Ying-Ting Chan
- Department of Physics and Astronomy, Rutgers University, Piscataway, NJ, USA
| | - Yu-Tsun Shao
- School of Applied and Engineering Physics, Cornell University, Ithaca, NY, USA
| | - Rui Chen
- Department of Materials Science and Engineering, University of California, Berkeley, Berkeley, CA, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Xiang Chen
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Department of Physics, University of California, Berkeley, Berkeley, CA, USA
| | - Xiaoxi Huang
- Department of Materials Science and Engineering, University of California, Berkeley, Berkeley, CA, USA
| | - Jonathan T. Reichanadter
- Department of Electrical Engineering, University of California, Berkeley, Berkeley, CA, USA
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, USA
| | - Kaichen Dong
- Department of Materials Science and Engineering, University of California, Berkeley, Berkeley, CA, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Sandhya Susarla
- Department of Materials Science and Engineering, University of California, Berkeley, Berkeley, CA, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Lucas Caretta
- Department of Materials Science and Engineering, University of California, Berkeley, Berkeley, CA, USA
| | - Zhen Chen
- School of Applied and Engineering Physics, Cornell University, Ithaca, NY, USA
| | - Jie Yao
- Department of Materials Science and Engineering, University of California, Berkeley, Berkeley, CA, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Peter Fischer
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Physics Department, University of California, Santa Cruz, Santa Cruz, CA, USA
| | - Jeffrey B. Neaton
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Department of Physics, University of California, Berkeley, Berkeley, CA, USA
- Kavli Energy Nanosciences Institute at Berkeley, Berkeley, CA, USA
| | - Weida Wu
- Department of Physics and Astronomy, Rutgers University, Piscataway, NJ, USA
| | - David A. Muller
- School of Applied and Engineering Physics, Cornell University, Ithaca, NY, USA
- Kavli Institute at Cornell for Nanoscale Science, Cornell University, Ithaca, NY, USA
| | - Robert J. Birgeneau
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Department of Physics, University of California, Berkeley, Berkeley, CA, USA
| | - Ramamoorthy Ramesh
- Department of Materials Science and Engineering, University of California, Berkeley, Berkeley, CA, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Department of Physics, University of California, Berkeley, Berkeley, CA, USA
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Stenning KD, Gartside JC, Dion T, Vanstone A, Arroo DM, Branford WR. Magnonic Bending, Phase Shifting and Interferometry in a 2D Reconfigurable Nanodisk Crystal. ACS Nano 2021; 15:674-685. [PMID: 33320533 DOI: 10.1021/acsnano.0c06894] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Strongly interacting nanomagnetic systems are pivotal across next-generation technologies including reconfigurable magnonics and neuromorphic computation. Controlling magnetization states and local coupling between neighboring nanoelements allows vast reconfigurability and a host of associated functionalities. However, existing designs typically suffer from an inability to tailor interelement coupling post-fabrication and nanoelements restricted to a pair of Ising-like magnetization states. Here, we propose a class of reconfigurable magnonic crystals incorporating nanodisks as the functional element. Ferromagnetic nanodisks are crucially bistable in macrospin and vortex states, allowing interelement coupling to be selectively activated (macrospin) or deactivated (vortex). Through microstate engineering, we leverage the distinct coupling behaviors and magnonic band structures of bistable nanodisks to achieve reprogrammable magnonic waveguiding, bending, gating, and phase-shifting across a 2D network. The potential of nanodisk-based magnonics for wave-based computation is demonstrated via an all-magnon interferometer exhibiting XNOR logic functionality. Local microstate control is achieved here via topological magnetic writing using a magnetic force microscope tip.
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Affiliation(s)
- Kilian D Stenning
- Blackett Laboratory, Imperial College London, London SW7 2AZ, United Kingdom
| | - Jack C Gartside
- Blackett Laboratory, Imperial College London, London SW7 2AZ, United Kingdom
| | - Troy Dion
- Blackett Laboratory, Imperial College London, London SW7 2AZ, United Kingdom
- London Centre for Nanotechnology, University College London, London WC1H 0AH, United Kingdom
| | - Alexander Vanstone
- Blackett Laboratory, Imperial College London, London SW7 2AZ, United Kingdom
| | - Daan M Arroo
- London Centre for Nanotechnology, University College London, London WC1H 0AH, United Kingdom
| | - Will R Branford
- Blackett Laboratory, Imperial College London, London SW7 2AZ, United Kingdom
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