1
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Sarott MF, Müller MJ, Lehmann J, Burgat BJ, Fiebig M, Trassin M. Reversible Optical Control of Polarization in Epitaxial Ferroelectric Thin Films. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024:e2312437. [PMID: 38341379 DOI: 10.1002/adma.202312437] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Revised: 01/19/2024] [Indexed: 02/12/2024]
Abstract
Light is an effective tool to probe the polarization and domain distribution in ferroelectric materials passively, that is, non-invasively, for example, via optical second harmonic generation (SHG). With the emergence of oxide electronics, there is now a strong demand to expand the role of light toward active control of the polarization. In this work, optical control of the ferroelectric polarization is demonstrated in prototypical epitaxial PbZrx Ti1-x O3 (PZT)-based heterostructures. This is accomplished in three steps, using above-bandgap UV light, while tracking the response of the polarization with optical SHG. First, it is found that UV-light exposure induces a transient enhancement or suppression of the ferroelectric polarization in films with an upward- or downward-oriented polarization, respectively. This behavior is attributed to a modified charge screening driven by the separation of photoexcited charge carriers at the Schottky interface of the ferroelectric thin film. Second, by taking advantage of this optical handle on electrostatics, remanent optical poling from a pristine multi-domain into a single-domain configuration is accomplished. Third, via thermal annealing or engineered electrostatic boundary conditions, a complete reversibility of the optical poling is further achieved. Hence, this work paves the way for the all-optical control of the spontaneous polarization in ferroelectric thin films.
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Affiliation(s)
- Martin F Sarott
- Department of Materials, ETH Zurich, CH-8093, Zurich, Switzerland
| | - Marvin J Müller
- Department of Materials, ETH Zurich, CH-8093, Zurich, Switzerland
| | - Jannis Lehmann
- Department of Materials, ETH Zurich, CH-8093, Zurich, Switzerland
- Center for Emergent Matter Science (CEMS), RIKEN, Wako, Saitama, 351-0198, Japan
- Department of Physics, ETH Zurich, CH-8093, Zurich, Switzerland
| | | | - Manfred Fiebig
- Department of Materials, ETH Zurich, CH-8093, Zurich, Switzerland
| | - Morgan Trassin
- Department of Materials, ETH Zurich, CH-8093, Zurich, Switzerland
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2
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Jang H, Ueda H, Kim HD, Kim M, Shin KW, Kim KH, Park SY, Shin HJ, Borisov P, Rosseinsky MJ, Jang D, Choi H, Eom I, Staub U, Chun SH. 4D Visualization of a Nonthermal Coherent Magnon in a Laser Heated Lattice by an X-ray Free Electron Laser. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2303032. [PMID: 37391904 DOI: 10.1002/adma.202303032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2023] [Revised: 06/27/2023] [Accepted: 06/29/2023] [Indexed: 07/02/2023]
Abstract
Ultrafast optical manipulation of magnetic phenomena is an exciting achievement of mankind, expanding one's horizon of knowledge toward the functional nonequilibrium states. The dynamics acting on an extremely short timescale push the detection limits that reveal fascinating light-matter interactions for nonthermal creation of effective magnetic fields. While some cases are benchmarked by emergent transient behaviors, otherwise identifying the nonthermal effects remains challenging. Here, a femtosecond time-resolved resonant magnetic X-ray diffraction experiment is introduced, which uses an X-ray free-electron laser (XFEL) to distinguish between the effective field and the photoinduced thermal effect. It is observed that a multiferroic Y-type hexaferrite exhibits magnetic Bragg peak intensity oscillations manifesting entangled antiferromagnetic (AFM) and ferromagnetic (FM) Fourier components of a coherent AFM magnon. The magnon trajectory constructed in 3D space and time domains is decisive to evince ultrafast field formation preceding the lattice thermalization. A remarkable impact of photoexcitation across the electronic bandgap is directly unraveled, amplifying the photomagnetic coupling that is one of the highest among AFM dielectrics. Leveraging the above-bandgap photoexcitation, this energy-efficient optical process further suggests a novel photomagnetic control of ferroelectricity in multiferroics.
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Affiliation(s)
- Hoyoung Jang
- Pohang Accelerator Laboratory, POSTECH, Pohang, Gyeongbuk, 37673, Republic of Korea
- Photon Science Center, POSTECH, Pohang, Gyeongbuk, 37673, Republic of Korea
| | - Hiroki Ueda
- Swiss Light Source, Paul Scherrer Institute, Villigen-PSI, 5232, Switzerland
- SwissFEL, Paul Scherrer Institute, Villigen-PSI, 5232, Switzerland
| | - Hyeong-Do Kim
- Pohang Accelerator Laboratory, POSTECH, Pohang, Gyeongbuk, 37673, Republic of Korea
| | - Minseok Kim
- Pohang Accelerator Laboratory, POSTECH, Pohang, Gyeongbuk, 37673, Republic of Korea
| | - Kwang Woo Shin
- Center for Novel States of Complex Materials Research, Department of Physics and Astronomy, Seoul National University, Seoul, 08826, Republic of Korea
| | - Kee Hoon Kim
- Center for Novel States of Complex Materials Research, Department of Physics and Astronomy, Seoul National University, Seoul, 08826, Republic of Korea
| | - Sang-Youn Park
- Pohang Accelerator Laboratory, POSTECH, Pohang, Gyeongbuk, 37673, Republic of Korea
| | - Hee Jun Shin
- Pohang Accelerator Laboratory, POSTECH, Pohang, Gyeongbuk, 37673, Republic of Korea
| | - Pavel Borisov
- Department of Physics, Loughborough University, Loughborough, LE11 3TU, UK
- Department of Chemistry, University of Liverpool, Liverpool, L7 3NY, UK
| | | | - Dogeun Jang
- Pohang Accelerator Laboratory, POSTECH, Pohang, Gyeongbuk, 37673, Republic of Korea
| | - Hyeongi Choi
- Pohang Accelerator Laboratory, POSTECH, Pohang, Gyeongbuk, 37673, Republic of Korea
| | - Intae Eom
- Pohang Accelerator Laboratory, POSTECH, Pohang, Gyeongbuk, 37673, Republic of Korea
- Photon Science Center, POSTECH, Pohang, Gyeongbuk, 37673, Republic of Korea
| | - Urs Staub
- Swiss Light Source, Paul Scherrer Institute, Villigen-PSI, 5232, Switzerland
| | - Sae Hwan Chun
- Pohang Accelerator Laboratory, POSTECH, Pohang, Gyeongbuk, 37673, Republic of Korea
- Photon Science Center, POSTECH, Pohang, Gyeongbuk, 37673, Republic of Korea
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3
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Matthiesen M, Hortensius JR, Mañas-Valero S, Kapon I, Dumcenco D, Giannini E, Šiškins M, Ivanov BA, van der Zant HSJ, Coronado E, Kuzmenko AB, Afanasiev D, Caviglia AD. Controlling Magnetism with Light in a Zero Orbital Angular Momentum Antiferromagnet. PHYSICAL REVIEW LETTERS 2023; 130:076702. [PMID: 36867817 DOI: 10.1103/physrevlett.130.076702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 11/17/2022] [Accepted: 12/21/2022] [Indexed: 06/18/2023]
Abstract
Antiferromagnetic materials feature intrinsic ultrafast spin dynamics, making them ideal candidates for future magnonic devices operating at THz frequencies. A major focus of current research is the investigation of optical methods for the efficient generation of coherent magnons in antiferromagnetic insulators. In magnetic lattices endowed with orbital angular momentum, spin-orbit coupling enables spin dynamics through the resonant excitation of low-energy electric dipoles such as phonons and orbital resonances which interact with spins. However, in magnetic systems with zero orbital angular momentum, microscopic pathways for the resonant and low-energy optical excitation of coherent spin dynamics are lacking. Here, we consider experimentally the relative merits of electronic and vibrational excitations for the optical control of zero orbital angular momentum magnets, focusing on a limit case: the antiferromagnet manganese phosphorous trisulfide (MnPS_{3}), constituted by orbital singlet Mn^{2+} ions. We study the correlation of spins with two types of excitations within its band gap: a bound electron orbital excitation from the singlet orbital ground state of Mn^{2+} into an orbital triplet state, which causes coherent spin precession, and a vibrational excitation of the crystal field that causes thermal spin disorder. Our findings cast orbital transitions as key targets for magnetic control in insulators constituted by magnetic centers of zero orbital angular momentum.
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Affiliation(s)
- Mattias Matthiesen
- Kavli Institute of Nanoscience, Delft University of Technology, P.O. Box 5046, 2600 GA Delft, Netherlands
- DQMP-University of Geneva, École de Physique, 24, Quai Ernest-Ansermet, CH-1211 Geneva, Switzerland
| | - Jorrit R Hortensius
- Kavli Institute of Nanoscience, Delft University of Technology, P.O. Box 5046, 2600 GA Delft, Netherlands
| | - Samuel Mañas-Valero
- Instituto de Ciencia Molecular (ICMol), Universitat de Valencia, Catedrático José Beltrán 2, 46980 Paterna, Spain
| | - Itzik Kapon
- DQMP-University of Geneva, École de Physique, 24, Quai Ernest-Ansermet, CH-1211 Geneva, Switzerland
| | - Dumitru Dumcenco
- DQMP-University of Geneva, École de Physique, 24, Quai Ernest-Ansermet, CH-1211 Geneva, Switzerland
| | - Enrico Giannini
- DQMP-University of Geneva, École de Physique, 24, Quai Ernest-Ansermet, CH-1211 Geneva, Switzerland
| | - Makars Šiškins
- Kavli Institute of Nanoscience, Delft University of Technology, P.O. Box 5046, 2600 GA Delft, Netherlands
| | - Boris A Ivanov
- Radboud University, Institute for Molecules and Materials, 6525 AJ Nijmegen, Netherlands
- Institute of Magnetism, National Academy of Sciences and Ministry of Education and Science, 03142 Kyiv, Ukraine
| | - Herre S J van der Zant
- Kavli Institute of Nanoscience, Delft University of Technology, P.O. Box 5046, 2600 GA Delft, Netherlands
| | - Eugenio Coronado
- Instituto de Ciencia Molecular (ICMol), Universitat de Valencia, Catedrático José Beltrán 2, 46980 Paterna, Spain
| | - Alexey B Kuzmenko
- DQMP-University of Geneva, École de Physique, 24, Quai Ernest-Ansermet, CH-1211 Geneva, Switzerland
| | - Dmytro Afanasiev
- Radboud University, Institute for Molecules and Materials, 6525 AJ Nijmegen, Netherlands
| | - Andrea D Caviglia
- DQMP-University of Geneva, École de Physique, 24, Quai Ernest-Ansermet, CH-1211 Geneva, Switzerland
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4
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Ergeçen E, Ilyas B, Mao D, Po HC, Yilmaz MB, Kim J, Park JG, Senthil T, Gedik N. Magnetically brightened dark electron-phonon bound states in a van der Waals antiferromagnet. Nat Commun 2022; 13:98. [PMID: 35013277 PMCID: PMC8748959 DOI: 10.1038/s41467-021-27741-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Accepted: 12/08/2021] [Indexed: 11/27/2022] Open
Abstract
In van der Waals (vdW) materials, strong coupling between different degrees of freedom can hybridize elementary excitations into bound states with mixed character1–3. Correctly identifying the nature and composition of these bound states is key to understanding their ground state properties and excitation spectra4,5. Here, we use ultrafast spectroscopy to reveal bound states of d-orbitals and phonons in 2D vdW antiferromagnet NiPS3. These bound states manifest themselves through equally spaced phonon replicas in frequency domain. These states are optically dark above the Néel temperature and become accessible with magnetic order. By launching this phonon and spectrally tracking its amplitude, we establish the electronic origin of bound states as localized d–d excitations. Our data directly yield electron-phonon coupling strength which exceeds the highest known value in 2D systems6. These results demonstrate NiPS3 as a platform to study strong interactions between spins, orbitals and lattice, and open pathways to coherent control of 2D magnets. Van der Waals materials can exhibit strong coupling between the lattice and other degrees of freedom. Here, Ergeçen et al reveal the presence of bound states emerging from the strong interaction between the lattice vibrations and d-orbitals in the van der Waals antiferromagnet NiPS3.
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Affiliation(s)
- Emre Ergeçen
- Department of Physics, Massachusetts Institute of Technology, Cambridge, 02139, MA, USA
| | - Batyr Ilyas
- Department of Physics, Massachusetts Institute of Technology, Cambridge, 02139, MA, USA
| | - Dan Mao
- Department of Physics, Massachusetts Institute of Technology, Cambridge, 02139, MA, USA
| | - Hoi Chun Po
- Department of Physics, Massachusetts Institute of Technology, Cambridge, 02139, MA, USA.,Department of Physics, Hong Kong Univesity of Science and Technology, Clear Water Bay, Hong Kong, 999077, China
| | - Mehmet Burak Yilmaz
- Department of Physics, Massachusetts Institute of Technology, Cambridge, 02139, MA, USA
| | - Junghyun Kim
- Center for Quantum Materials, Seoul National University, Seoul, 08826, Republic of Korea.,Department of Physics and Astronomy and Institute of Applied Physics, Seoul National University, Seoul, 08826, Republic of Korea
| | - Je-Geun Park
- Center for Quantum Materials, Seoul National University, Seoul, 08826, Republic of Korea.,Department of Physics and Astronomy and Institute of Applied Physics, Seoul National University, Seoul, 08826, Republic of Korea
| | - T Senthil
- Department of Physics, Massachusetts Institute of Technology, Cambridge, 02139, MA, USA
| | - Nuh Gedik
- Department of Physics, Massachusetts Institute of Technology, Cambridge, 02139, MA, USA.
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5
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Hortensius J, Afanasiev D, Matthiesen M, Leenders R, Citro R, Kimel A, Mikhaylovskiy R, Ivanov B, Caviglia A. Coherent spin-wave transport in an antiferromagnet. NATURE PHYSICS 2021; 17:1001-1006. [PMID: 34512793 PMCID: PMC7611635 DOI: 10.1038/s41567-021-01290-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Accepted: 06/04/2021] [Indexed: 06/03/2023]
Abstract
Magnonics is a research field complementary to spintronics, in which quanta of spin waves (magnons) replace electrons as information carriers, promising lower dissipation1-3. The development of ultrafast nanoscale magnonic logic circuits calls for new tools and materials to generate coherent spin waves with frequencies as high, and wavelengths as short, as possible4,5. Antiferromagnets can host spin waves at terahertz (THz) frequencies and are therefore seen as a future platform for the fastest and the least dissipative transfer of information6-11. However, the generation of short-wavelength coherent propagating magnons in antiferromagnets has so far remained elusive. Here we report the efficient emission and detection of a nanometer-scale wavepacket of coherent propagating magnons in antiferromagnetic DyFeO3 using ultrashort pulses of light. The subwavelength confinement of the laser field due to large absorption creates a strongly non-uniform spin excitation profile, enabling the propagation of a broadband continuum of coherent THz spin waves. The wavepacket contains magnons with a shortest detected wavelength of 125 nm that propagate with supersonic velocities of more than 13 km/s into the material. This source of coherent short-wavelength spin carriers opens up new prospects for THz antiferromagnetic magnonics and coherence-mediated logic devices at THz frequencies.
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Affiliation(s)
- J.R. Hortensius
- Kavli Institute of Nanoscience, Delft University of Technology, P.O. Box 5046, 2600 GA Delft, The Netherlands
| | - D. Afanasiev
- Kavli Institute of Nanoscience, Delft University of Technology, P.O. Box 5046, 2600 GA Delft, The Netherlands
| | - M. Matthiesen
- Kavli Institute of Nanoscience, Delft University of Technology, P.O. Box 5046, 2600 GA Delft, The Netherlands
| | - R. Leenders
- Department of Physics, Lancaster University, Bailrigg, Lancaster LA1 4YW, United Kingdom
| | - R. Citro
- Dipartimento di Fisica “E.R. Caianiello”, Università di Salerno and Spin-CNR, I-84084 Fisciano (Sa), Italy
| | - A.V. Kimel
- Institute for Molecules and Materials, Radboud University Nijmegen, 6525 AJ Nijmegen, The Netherlands
| | - R.V. Mikhaylovskiy
- Department of Physics, Lancaster University, Bailrigg, Lancaster LA1 4YW, United Kingdom
| | - B.A. Ivanov
- Institute of Magnetism, National Academy of Sciences and Ministry of Education and Science, 03142 Kyiv, Ukraine
| | - A.D. Caviglia
- Kavli Institute of Nanoscience, Delft University of Technology, P.O. Box 5046, 2600 GA Delft, The Netherlands
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6
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Energy-efficient ultrafast nucleation of single and multiple antiferromagnetic skyrmions using in-plane spin polarized current. Sci Rep 2021; 11:12332. [PMID: 34112862 PMCID: PMC8192941 DOI: 10.1038/s41598-021-91591-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Accepted: 05/13/2021] [Indexed: 11/09/2022] Open
Abstract
We numerically investigate the ultrafast nucleation of antiferromagnetic (AFM) skyrmion using in-plane spin-polarized current and present its key advantages over out-of-plane spin-polarized current. We show that the threshold current density required for the creation of AFM skyrmion is almost an order of magnitude lower for the in-plane spin-polarized current. The nucleation time for the AFM skyrmion is found to be [Formula: see text] ps for the corresponding current density of 1-[Formula: see text]. We also demonstrate ultrafast nucleation of multiple AFM skyrmions that is possible only with in-plane spin polarized current and discuss how the current pulse width can be used to control the number of AFM skyrmions. The results show more than one order of magnitude improvement in energy consumption for ultrafast nucleation of AFM skyrmions using in-plane spin-polarized current, which is promising for applications such as logic gates, racetrack memory, and neuromorphic computing.
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7
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Reversible hydrogen control of antiferromagnetic anisotropy in α-Fe 2O 3. Nat Commun 2021; 12:1668. [PMID: 33712582 PMCID: PMC7954816 DOI: 10.1038/s41467-021-21807-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Accepted: 02/04/2021] [Indexed: 11/14/2022] Open
Abstract
Antiferromagnetic insulators are a ubiquitous class of magnetic materials, holding the promise of low-dissipation spin-based computing devices that can display ultra-fast switching and are robust against stray fields. However, their imperviousness to magnetic fields also makes them difficult to control in a reversible and scalable manner. Here we demonstrate a novel proof-of-principle ionic approach to control the spin reorientation (Morin) transition reversibly in the common antiferromagnetic insulator α-Fe2O3 (haematite) – now an emerging spintronic material that hosts topological antiferromagnetic spin-textures and long magnon-diffusion lengths. We use a low-temperature catalytic-spillover process involving the post-growth incorporation or removal of hydrogen from α-Fe2O3 thin films. Hydrogenation drives pronounced changes in its magnetic anisotropy, Néel vector orientation and canted magnetism via electron injection and local distortions. We explain these effects with a detailed magnetic anisotropy model and first-principles calculations. Tailoring our work for future applications, we demonstrate reversible control of the room-temperature spin-state by doping/expelling hydrogen in Rh-substituted α-Fe2O3. One major challenge for antiferromagnetic spintronics is how to control the antiferromagnetic state. Here Jani et al. demonstrate the reversible ionic control of the room-temperature magnetic anisotropy and spin reorientation transition in haematite, via the incorporation and removal of hydrogen.
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8
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Aryal S, Paudyal D, Pati R. Cr-Doped Ge-Core/Si-Shell Nanowire: An Antiferromagnetic Semiconductor. NANO LETTERS 2021; 21:1856-1862. [PMID: 33577344 DOI: 10.1021/acs.nanolett.0c04971] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
An antiferromagnet offers many important functionalities such as opportunities for electrical control of magnetic domains, immunity from magnetic perturbations, and fast spin dynamics. Introducing some of these intriguing features of an antiferromagnet into a low dimensional semiconductor core-shell nanowire offers an exciting pathway for its usage in antiferromagnetic semiconductor spintronics. Here, using a quantum mechanical approach, we predict that the Cr-doped Ge-core/Si-shell nanowire behaves as an antiferromagnetic semiconductor. The origin of antiferromagnetic spin alignments between Cr is attributed to the superexchange interaction mediated by the pz orbitals of the Ge atoms that are bonded to Cr. A weak spin-orbit interaction was found in this material, suggesting a longer spin coherence length. The spin-dependent quantum transport calculations in the Cr-doped nanowire junction reveals a switching feature with a high ON/OFF current ratio (∼41 times higher for the ON state at a relatively small bias of 0.83 V).
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Affiliation(s)
- Sandip Aryal
- Department of Physics, Michigan Technological University, Houghton, Michigan 49931, United States
| | - Durga Paudyal
- The Ames Laboratory, U.S. Department of Energy, Iowa State University, Ames, Iowa 50011, United States
- Electrical and Computer Engineering Department, Iowa State University, Ames, Iowa 50011, United States
| | - Ranjit Pati
- Department of Physics, Michigan Technological University, Houghton, Michigan 49931, United States
- Henes Center for Quantum Phenomena, Michigan Technological University, Houghton, Michigan 49931, United States
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9
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Guang Y, Peng Y, Yan Z, Liu Y, Zhang J, Zeng X, Zhang S, Zhang S, Burn DM, Jaouen N, Wei J, Xu H, Feng J, Fang C, van der Laan G, Hesjedal T, Cui B, Zhang X, Yu G, Han X. Electron Beam Lithography of Magnetic Skyrmions. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2020; 32:e2003003. [PMID: 32812294 DOI: 10.1002/adma.202003003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 06/27/2020] [Indexed: 05/08/2023]
Abstract
The emergence of magnetic skyrmions, topological spin textures, has aroused tremendous interest in studying the rich physics related to their topology. While skyrmions promise high-density and energy-efficient magnetic memory devices for information technology, the manifestation of their nontrivial topology through single skyrmions and ordered and disordered skyrmion lattices could also give rise to many fascinating physical phenomena, such as chiral magnon and skyrmion glass states. Therefore, generating skyrmions at designated locations on a large scale, while controlling the skyrmion patterns, is the key to advancing topological magnetism. Here, a new, yet general, approach to the "printing" of skyrmions with zero-field stability in arbitrary patterns on a massive scale in exchange-biased magnetic multilayers is presented. By exploiting the fact that the antiferromagnetic order can be reconfigured by local thermal excitations, a focused electron beam with a graphic pattern generator to "print" skyrmions is used, which is referred to as skyrmion lithography. This work provides a route to design arbitrary skyrmion patterns, thereby establishing the foundation for further exploration of topological magnetism.
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Affiliation(s)
- Yao Guang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yong Peng
- Key Laboratory for Magnetism and Magnetic Materials of Ministry of Education, Lanzhou University, Lanzhou, 730000, China
| | - Zhengren Yan
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yizhou Liu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Junwei Zhang
- Key Laboratory for Magnetism and Magnetic Materials of Ministry of Education, Lanzhou University, Lanzhou, 730000, China
- Physical Science and Engineering Division (PSE), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia
| | - Xue Zeng
- School of Mathematics and Physics, Lanzhou Jiaotong University, Lanzhou, 730070, China
| | - Senfu Zhang
- Physical Science and Engineering Division (PSE), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia
| | - Shilei Zhang
- ShanghaiTech Laboratory for Topological Physics, ShanghaiTech University, Shanghai, 201210, China
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - David M Burn
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire, OX11 0DE, UK
| | - Nicolas Jaouen
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint-Aubin, Gif-sur-Yvette, 91192, France
| | - Jinwu Wei
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong, 523808, China
| | - Hongjun Xu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong, 523808, China
| | - Jiafeng Feng
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Chi Fang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Gerrit van der Laan
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire, OX11 0DE, UK
| | - Thorsten Hesjedal
- Department of Physics, Clarendon Laboratory, University of Oxford, Parks Road, Oxford, OX1 3PU, UK
| | - Baoshan Cui
- Songshan Lake Materials Laboratory, Dongguan, Guangdong, 523808, China
| | - Xixiang Zhang
- Physical Science and Engineering Division (PSE), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia
| | - Guoqiang Yu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong, 523808, China
| | - Xiufeng Han
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong, 523808, China
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10
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Creating zero-field skyrmions in exchange-biased multilayers through X-ray illumination. Nat Commun 2020; 11:949. [PMID: 32075968 PMCID: PMC7031520 DOI: 10.1038/s41467-020-14769-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Accepted: 01/29/2020] [Indexed: 11/15/2022] Open
Abstract
Skyrmions, magnetic textures with topological stability, hold promises for high-density and energy-efficient information storage devices owing to their small size and low driving-current density. Precise creation of a single nanoscale skyrmion is a prerequisite to further understand the skyrmion physics and tailor skyrmion-based applications. Here, we demonstrate the creation of individual skyrmions at zero-field in an exchange-biased magnetic multilayer with exposure to soft X-rays. In particular, a single skyrmion with 100-nm size can be created at the desired position using a focused X-ray spot of sub-50-nm size. This single skyrmion creation is driven by the X-ray-induced modification of the antiferromagnetic order and the corresponding exchange bias. Furthermore, artificial skyrmion lattices with various arrangements can be patterned using X-ray. These results demonstrate the potential of accurate optical control of single skyrmion at sub-100 nm scale. We envision that X-ray could serve as a versatile tool for local manipulation of magnetic orders. Skyrmions are objects with whirled magnetization protected by their topology that can be created by different means, however, without control of their position. Here, the authors present a method exploiting x-rays to create skyrmions at the beam position allowing for creation of artificial skyrmion lattices.
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11
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Yang MM, Alexe M. Light-Induced Reversible Control of Ferroelectric Polarization in BiFeO 3. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2018; 30:e1704908. [PMID: 29457305 DOI: 10.1002/adma.201704908] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2017] [Revised: 12/22/2017] [Indexed: 06/08/2023]
Abstract
Manipulation of ferroic order parameters, namely (anti-)ferromagnetic, ferroelectric, and ferroelastic, by light at room temperature is a fascinating topic in modern solid-state physics due to potential cross-fertilization in research fields that are largely decoupled. Here, full optical control, that is, reversible switching, of the ferroelectric/ferroelastic domains in BiFeO3 thin films at room temperature by the mediation of the tip-enhanced photovoltaic effect is demonstrated. The enhanced short-circuit photocurrent density at the tip contact area generates a local electric field well exceeding the coercive field, enabling ferroelectric polarization switching. Interestingly, by tailoring the photocurrent direction, via either tuning the illumination geometry or simply rotating the light polarization, full control of the ferroelectric polarization is achieved. The finding offers a new insight into the interactions between light and ferroic orders, enabling fully optical control of all the ferroic orders at room temperature and providing guidance to design novel optoferroic devices for data storage and sensing.
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Affiliation(s)
- Ming-Min Yang
- Department of Physics, The University of Warwick, Coventry, CV4 7AL, UK
| | - Marin Alexe
- Department of Physics, The University of Warwick, Coventry, CV4 7AL, UK
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12
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Song C, You Y, Chen X, Zhou X, Wang Y, Pan F. How to manipulate magnetic states of antiferromagnets. NANOTECHNOLOGY 2018; 29:112001. [PMID: 29337295 DOI: 10.1088/1361-6528/aaa812] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Antiferromagnetic materials, which have drawn considerable attention recently, have fascinating features: they are robust against perturbation, produce no stray fields, and exhibit ultrafast dynamics. Discerning how to efficiently manipulate the magnetic state of an antiferromagnet is key to the development of antiferromagnetic spintronics. In this review, we introduce four main methods (magnetic, strain, electrical, and optical) to mediate the magnetic states and elaborate on intrinsic origins of different antiferromagnetic materials. Magnetic control includes a strong magnetic field, exchange bias, and field cooling, which are traditional and basic. Strain control involves the magnetic anisotropy effect or metamagnetic transition. Electrical control can be divided into two parts, electric field and electric current, both of which are convenient for practical applications. Optical control includes thermal and electronic excitation, an inertia-driven mechanism, and terahertz laser control, with the potential for ultrafast antiferromagnetic manipulation. This review sheds light on effective usage of antiferromagnets and provides a new perspective on antiferromagnetic spintronics.
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Affiliation(s)
- Cheng Song
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing 100084, People's Republic of China. Beijing Innovation Center for Future Chip, Tsinghua University, Beijing 100084, People's Republic of China
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13
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Li J, Haney PM. Optical spin transfer and spin-orbit torques in thin film ferromagnets. PHYSICAL REVIEW. B 2017; 96:054447. [PMID: 29167836 PMCID: PMC5695756 DOI: 10.1103/physrevb.96.054447] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
We study the optically induced torques in thin film ferromagnetic layers under excitation by circularly polarized light. We study cases both with and without Rashba spin-orbit coupling using a 4-band model. In the absence of Rashba spin-orbit coupling, we derive an analytic expression for the optical torques, revealing the conditions under which the torque is mostly derived from optical spin transfer torque (i.e. when the torque is along the direction of optical angular momentum), versus when the torque is derived from the inverse Faraday effect (i.e. when the torque is perpendicular to the optical angular momentum). We find the optical spin transfer torque dominates provided that the excitation energy is far away from band edge transitions, and the magnetic exchange splitting is much greater than the lifetime broadening. For the case with large Rashba spin-orbit coupling and out-of-plane magnetization, we find the torque is generally perpendicular to the photon angular momentum and is ascribed to an optical Edelstein effect.
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Affiliation(s)
- Junwen Li
- Center for Nanoscale Science and Technology, National Institute of Standards and Technology, Gaithersburg, MD 20899
- Maryland NanoCenter, University of Maryland, College Park, MD 20742, USA
| | - Paul M Haney
- Center for Nanoscale Science and Technology, National Institute of Standards and Technology, Gaithersburg, MD 20899
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14
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Ma X, Fang F, Li Q, Zhu J, Yang Y, Wu YZ, Zhao HB, Lüpke G. Ultrafast spin exchange-coupling torque via photo-excited charge-transfer processes. Nat Commun 2015; 6:8800. [PMID: 26508587 PMCID: PMC4640140 DOI: 10.1038/ncomms9800] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Accepted: 10/05/2015] [Indexed: 11/10/2022] Open
Abstract
Optical control of spin is of central importance in the research of ultrafast spintronic devices utilizing spin dynamics at short time scales. Recently developed optical approaches such as ultrafast demagnetization, spin-transfer and spin-orbit torques open new pathways to manipulate spin through its interaction with photon, orbit, charge or phonon. However, these processes are limited by either the long thermal recovery time or the low-temperature requirement. Here we experimentally demonstrate ultrafast coherent spin precession via optical charge-transfer processes in the exchange-coupled Fe/CoO system at room temperature. The efficiency of spin precession excitation is significantly higher and the recovery time of the exchange-coupling torque is much shorter than for the demagnetization procedure, which is desirable for fast switching. The exchange coupling is a key issue in spin valves and tunnelling junctions, and hence our findings will help promote the development of exchange-coupled device concepts for ultrafast coherent spin manipulation. Light can provide ultrafast ways of spin manipulation in magnetic materials, but existing methods are limited by long thermal recovery or low temperature. Here, the authors demonstrate ultrafast spin precession via optical charge-transfer processes in exchange-coupled Fe/CoO at room temperature.
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Affiliation(s)
- X Ma
- Department of Applied Science, College of William and Mary, 251 Jamestown Road, Williamsburg, Virginia 23187, USA
| | - F Fang
- Department of Applied Science, College of William and Mary, 251 Jamestown Road, Williamsburg, Virginia 23187, USA
| | - Q Li
- State Key Laboratory of Surface Physics, Department of Physics, and Collaborative Innovation Center of Advanced Microstructures, Fudan University, Shanghai 200433, China
| | - J Zhu
- State Key Laboratory of Surface Physics, Department of Physics, and Collaborative Innovation Center of Advanced Microstructures, Fudan University, Shanghai 200433, China
| | - Y Yang
- State Key Laboratory of Surface Physics, Department of Physics, and Collaborative Innovation Center of Advanced Microstructures, Fudan University, Shanghai 200433, China
| | - Y Z Wu
- State Key Laboratory of Surface Physics, Department of Physics, and Collaborative Innovation Center of Advanced Microstructures, Fudan University, Shanghai 200433, China
| | - H B Zhao
- Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education), Department of Optical Science and Engineering, Fudan University, Shanghai, 200433, China
| | - G Lüpke
- Department of Applied Science, College of William and Mary, 251 Jamestown Road, Williamsburg, Virginia 23187, USA
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15
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Li J, Higuchi T, Kanda N, Konishi K, Tikhodeev SG, Kuwata-Gonokami M. Control of magnetic dipole terahertz radiation by cavity-based phase modulation. OPTICS EXPRESS 2011; 19:22550-22556. [PMID: 22109133 DOI: 10.1364/oe.19.022550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Although it is well accepted that the ultrafast manipulation of spins or magnetization in solid promises potential applications in coherent terahertz (THz) radiation source, spintronics and quantum information processing, their performance is significantly limited by the weak coupling between radiation field and magnetic dipole oscillation. For such 'weak' magnetic system, we propose an effective and simple route based on the cavity-based phase modulation technique towards the efficient energy extraction, demonstrated via controlling the magnetic dipole THz radiation generated in the nonlinear Raman process from antiferromagnetic (AFM) NiO. An asymmetric coupled Fabry-Pérot (FP) cavity is constituted by simply placing a metallic planar mirror in the vicinity of a NiO slab. The energy-extraction (THz radiation) can be effectively manipulated by changing the NiO-mirror distance to modulate the phase relation between the magnetic wave and the induced magnetization in NiO. The distinct radiation control can be observed and the experiments are well explained by numerically analyzing the radiation dynamics that highlights the role of phase modulation during the radiation process.
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Affiliation(s)
- J Li
- Department of Applied Physics, The University of Tokyo and CREST-JST, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan
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16
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Kanda N, Higuchi T, Shimizu H, Konishi K, Yoshioka K, Kuwata-Gonokami M. The vectorial control of magnetization by light. Nat Commun 2011; 2:362. [PMID: 21694710 PMCID: PMC3156816 DOI: 10.1038/ncomms1366] [Citation(s) in RCA: 113] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2011] [Accepted: 05/24/2011] [Indexed: 12/05/2022] Open
Abstract
Application of coherent light–matter interactions has recently been extended to the ultrafast control of magnetization. An important but unrealized technique is the manipulation of magnetization vector motion to make it follow an arbitrarily designed multidimensional trajectory. Here we demonstrate a full manipulation of two-dimensional magnetic oscillations in antiferromagnetic NiO with a pair of polarization-twisted femtosecond laser pulses. We employ Raman-type nonlinear optical processes, wherein magnetic oscillations are impulsively induced with a controlled initial phase. Their azimuthal angle follows well-defined selection rules that have been determined by the symmetries of the materials. We emphasize that the temporal variation of the laser-pulse polarization angle enables us to control the phase and amplitude of the two degenerate modes, independently. These results lead to a new concept of the vectorial control of magnetization by light. Light–matter interactions can be used to manipulate magnetization in solids, but light-controlled magnetization vector motion has not been demonstrated. Here, two-dimensional magnetic oscillations in NiO are manipulated with optical pulses leading to vectorial control of magnetization by light.
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Affiliation(s)
- Natsuki Kanda
- Department of Applied Physics, The University of Tokyo and Core Research for Evolutional Science and Technology, Tokyo 113-8656, Japan
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Higuchi T, Kanda N, Tamaru H, Kuwata-Gonokami M. Selection rules for light-induced magnetization of a crystal with threefold symmetry: the case of antiferromagnetic NiO. PHYSICAL REVIEW LETTERS 2011; 106:047401. [PMID: 21405359 DOI: 10.1103/physrevlett.106.047401] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2010] [Indexed: 05/30/2023]
Abstract
We propose Raman-induced collinear difference-frequency generation (DFG) as a method to manipulate dynamical magnetization. When a fundamental beam propagates along a threefold rotational axis, this coherent second-order optical process is permitted by angular momentum conservation through the rotational analogue of the umklapp process. As a demonstration, we experimentally obtained polarization properties of collinear magnetic DFG along a [111] axis of a single crystal of antiferromagnetic NiO with micromultidomain structure, which excellently agreed with the theoretical prediction.
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Affiliation(s)
- Takuya Higuchi
- Department of Applied Physics, The University of Tokyo and CREST-JST, Tokyo, Japan
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18
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Satoh T, Cho SJ, Iida R, Shimura T, Kuroda K, Ueda H, Ueda Y, Ivanov BA, Nori F, Fiebig M. Spin oscillations in antiferromagnetic NiO triggered by circularly polarized light. PHYSICAL REVIEW LETTERS 2010; 105:077402. [PMID: 20868075 DOI: 10.1103/physrevlett.105.077402] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2009] [Indexed: 05/29/2023]
Abstract
Coherent spin oscillations were nonthermally induced by circularly polarized pulses in the fully compensated antiferromagnet NiO. This effect is attributed to the action of the effective magnetic field generated by an inverse Faraday effect on the spins. The novelty of this mechanism is that spin oscillations are driven by the time derivative of the effective magnetic field which acts even on "pure" antiferromagnets with zero net magnetic moment in the ground state. The measured frequencies (1.07 THz and 140 GHz) correspond to the out-of-plane and in-plane modes of antiferromagnetic spin oscillations.
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Affiliation(s)
- Takuya Satoh
- Institute of Industrial Science, University of Tokyo, Tokyo 153-8505, Japan
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Yang LX, Zhu YJ, Tong H, Liang ZH, Li L, Zhang L. Hydrothermal synthesis of nickel hydroxide nanostructures in mixed solvents of water and alcohol. J SOLID STATE CHEM 2007. [DOI: 10.1016/j.jssc.2007.05.009] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Hansteen F, Kimel A, Kirilyuk A, Rasing T. Femtosecond photomagnetic switching of spins in ferrimagnetic garnet films. PHYSICAL REVIEW LETTERS 2005; 95:047402. [PMID: 16090839 DOI: 10.1103/physrevlett.95.047402] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2005] [Indexed: 05/03/2023]
Abstract
We demonstrate that intense laser pulses can be used to directly control the spins in ferrimagnetic garnet films. Through an ultrafast and nonthermal photomagnetic effect the magnetocrystalline anisotropy is modified to create a new long-lived equilibrium orientation for the magnetization. Simultaneously, the magnetization is rotated into this new state by precession in a strong transient optically generated magnetic field. All take place within the 100 fs duration of a single laser pulse, thus demonstrating the feasibility of photomagnetic switching on the femtosecond time scale.
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