1
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Yang D, Kim T, Lee K, Xu C, Liu Y, Wang F, Zhao S, Kumar D, Yang H. Spin-orbit torque manipulation of sub-terahertz magnons in antiferromagnetic α-Fe 2O 3. Nat Commun 2024; 15:4046. [PMID: 38744961 PMCID: PMC11094109 DOI: 10.1038/s41467-024-48431-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Accepted: 05/01/2024] [Indexed: 05/16/2024] Open
Abstract
The ability to electrically manipulate antiferromagnetic magnons, essential for extending the operating speed of spintronic devices into the terahertz regime, remains a major challenge. This is because antiferromagnetic magnetism is challenging to perturb using traditional methods such as magnetic fields. Recent developments in spin-orbit torques have opened a possibility of accessing antiferromagnetic magnetic order parameters and controlling terahertz magnons, which has not been experimentally realised yet. Here, we demonstrate the electrical manipulation of sub-terahertz magnons in the α-Fe2O3/Pt antiferromagnetic heterostructure. By applying the spin-orbit torques in the heterostructure, we can modify the magnon dispersion and decrease the magnon frequency in α-Fe2O3, as detected by time-resolved magneto-optical techniques. We have found that optimal tuning occurs when the Néel vector is perpendicular to the injected spin polarisation. Our results represent a significant step towards the development of electrically tunable terahertz spintronic devices.
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Affiliation(s)
- Dongsheng Yang
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore, Singapore
| | - Taeheon Kim
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore, Singapore
- Electro-Medical Device Research Centre, Korea Electrotechnology Research Institute, Ansan, Republic of Korea
| | - Kyusup Lee
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore, Singapore
| | - Chang Xu
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore, Singapore
| | - Yakun Liu
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore, Singapore
| | - Fei Wang
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore, Singapore
| | - Shishun Zhao
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore, Singapore
| | - Dushyant Kumar
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore, Singapore
| | - Hyunsoo Yang
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore, Singapore.
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2
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Zhou X, Jiang T, Tao Y, Ji Y, Wang J, Lai T, Zhong D. Evidence of Ferromagnetism and Ultrafast Dynamics of Demagnetization in an Epitaxial FeCl 2 Monolayer. ACS NANO 2024; 18:10912-10920. [PMID: 38613502 DOI: 10.1021/acsnano.4c01436] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/15/2024]
Abstract
The development of two-dimensional (2D) magnetism is driven not only by the interest of low-dimensional physics but also by potential applications in high-density miniaturized spintronic devices. However, 2D materials possessing a ferromagnetic order with a relatively high Curie temperature (Tc) are rare. In this paper, the evidence of ferromagnetism in monolayer FeCl2 on Au(111) surfaces, as well as the interlayer antiferromagnetic coupling of bilayer FeCl2, is characterized by using spin-polarized scanning tunneling microscopy. A Curie temperature (Tc) of ∼147 K is revealed for monolayer FeCl2, based on our static magneto-optical Kerr effect measurements. Furthermore, temperature-dependent magnetization dynamics is investigated by the time-resolved magneto-optical Kerr effect. A transition from one- to two-step demagnetization occurs as the lattice temperature approaches Tc, which supports the Elliott-Yafet spin relaxation mechanism. The findings contribute to a deeper understanding of the underlying mechanisms governing ultrafast magnetization in 2D ferromagnetic materials.
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Affiliation(s)
- Xuhan Zhou
- School of Physics, Sun Yat-sen University, Guangzhou 510275, China
- State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-sen University, Guangzhou 510275, China
- Center for Neutron Science and Technology, School of Physics, Sun Yat-sen University, Guangzhou 510275, China
- Guangzhou No. 89 Secondary School, Guangzhou 510520, China
| | - Tianran Jiang
- School of Physics, Sun Yat-sen University, Guangzhou 510275, China
- State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-sen University, Guangzhou 510275, China
| | - Ye Tao
- School of Physics, Sun Yat-sen University, Guangzhou 510275, China
- State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-sen University, Guangzhou 510275, China
- Center for Neutron Science and Technology, School of Physics, Sun Yat-sen University, Guangzhou 510275, China
| | - Yi Ji
- School of Physics, Sun Yat-sen University, Guangzhou 510275, China
- State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-sen University, Guangzhou 510275, China
- Center for Neutron Science and Technology, School of Physics, Sun Yat-sen University, Guangzhou 510275, China
| | - Jingying Wang
- School of Physics, Sun Yat-sen University, Guangzhou 510275, China
- State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-sen University, Guangzhou 510275, China
- Center for Neutron Science and Technology, School of Physics, Sun Yat-sen University, Guangzhou 510275, China
| | - Tianshu Lai
- School of Physics, Sun Yat-sen University, Guangzhou 510275, China
- State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-sen University, Guangzhou 510275, China
| | - Dingyong Zhong
- School of Physics, Sun Yat-sen University, Guangzhou 510275, China
- State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-sen University, Guangzhou 510275, China
- Center for Neutron Science and Technology, School of Physics, Sun Yat-sen University, Guangzhou 510275, China
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3
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Barajas-Aguilar AH, Zion J, Sequeira I, Barabas AZ, Taniguchi T, Watanabe K, Barrett EB, Scaffidi T, Sanchez-Yamagishi JD. Electrically driven amplification of terahertz acoustic waves in graphene. Nat Commun 2024; 15:2550. [PMID: 38514632 PMCID: PMC10957956 DOI: 10.1038/s41467-024-46819-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Accepted: 03/12/2024] [Indexed: 03/23/2024] Open
Abstract
In graphene devices, the electronic drift velocity can easily exceed the speed of sound in the material at moderate current biases. Under these conditions, the electronic system can efficiently amplify acoustic phonons, leading to an exponential growth of sound waves in the direction of the carrier flow. Here, we show that such phonon amplification can significantly modify the electrical properties of graphene devices. We observe a superlinear growth of the resistivity in the direction of the carrier flow when the drift velocity exceeds the speed of sound - resulting in a sevenfold increase over a distance of 8 µm. The resistivity growth is observed at carrier densities away from the Dirac point and is enhanced at cryogenic temperatures. We develop a theoretical model for the resistivity growth due to the electrical amplification of acoustic phonons - reaching frequencies up to 2.2 THz - where the wavelength is controlled by gate-tunable transitions across the Fermi surface. These findings provide a route to on-chip high-frequency sound generation and detection in the THz frequency range.
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Affiliation(s)
| | - Jasen Zion
- T. J. Watson Laboratory of Applied Physics, California Institute of Technology, Pasadena, CA, USA
| | - Ian Sequeira
- Department of Physics and Astronomy, University of California, Irvine, Irvine, CA, USA
| | - Andrew Z Barabas
- Department of Physics and Astronomy, University of California, Irvine, Irvine, CA, USA
| | - Takashi Taniguchi
- Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Japan
| | - Kenji Watanabe
- Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Japan
| | - Eric B Barrett
- Department of Physics and Astronomy, University of California, Irvine, Irvine, CA, USA
| | - Thomas Scaffidi
- Department of Physics and Astronomy, University of California, Irvine, Irvine, CA, USA
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4
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Li Y, Zhang Z, Liu C, Zheng D, Fang B, Zhang C, Chen A, Ma Y, Wang C, Liu H, Shen K, Manchon A, Xiao JQ, Qiu Z, Hu CM, Zhang X. Reconfigurable spin current transmission and magnon-magnon coupling in hybrid ferrimagnetic insulators. Nat Commun 2024; 15:2234. [PMID: 38472180 DOI: 10.1038/s41467-024-46330-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Accepted: 02/22/2024] [Indexed: 03/14/2024] Open
Abstract
Coherent spin waves possess immense potential in wave-based information computation, storage, and transmission with high fidelity and ultra-low energy consumption. However, despite their seminal importance for magnonic devices, there is a paucity of both structural prototypes and theoretical frameworks that regulate the spin current transmission and magnon hybridization mediated by coherent spin waves. Here, we demonstrate reconfigurable coherent spin current transmission, as well as magnon-magnon coupling, in a hybrid ferrimagnetic heterostructure comprising epitaxial Gd3Fe5O12 and Y3Fe5O12 insulators. By adjusting the compensated moment in Gd3Fe5O12, magnon-magnon coupling was achieved and engineered with pronounced anticrossings between two Kittel modes, accompanied by divergent dissipative coupling approaching the magnetic compensation temperature of Gd3Fe5O12 (TM,GdIG), which were modeled by coherent spin pumping. Remarkably, we further identified, both experimentally and theoretically, a drastic variation in the coherent spin wave-mediated spin current across TM,GdIG, which manifested as a strong dependence on the relative alignment of magnetic moments. Our findings provide significant fundamental insight into the reconfiguration of coherent spin waves and offer a new route towards constructing artificial magnonic architectures.
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Affiliation(s)
- Yan Li
- Physical Science and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia
| | - Zhitao Zhang
- Guangdong Provincial Key Laboratory of Semiconductor, Optoelectronic Materials and Intelligent Photonic Systems, School of Science, Harbin Institute of Technology (Shenzhen), 518055, Shenzhen, China
| | - Chen Liu
- Physical Science and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia
| | - Dongxing Zheng
- Physical Science and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia
| | - Bin Fang
- Physical Science and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia
| | - Chenhui Zhang
- Physical Science and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia
| | - Aitian Chen
- Physical Science and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia
| | - Yinchang Ma
- Physical Science and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia
| | - Chunmei Wang
- Guangdong Provincial Key Laboratory of Semiconductor, Optoelectronic Materials and Intelligent Photonic Systems, School of Science, Harbin Institute of Technology (Shenzhen), 518055, Shenzhen, China
| | - Haoliang Liu
- Guangdong Provincial Key Laboratory of Semiconductor, Optoelectronic Materials and Intelligent Photonic Systems, School of Science, Harbin Institute of Technology (Shenzhen), 518055, Shenzhen, China.
| | - Ka Shen
- The Center for Advanced Quantum Studies and Department of Physics, Beijing Normal University, 100875, Beijing, China.
| | | | - John Q Xiao
- Department of Physics and Astronomy, University of Delaware, Newark, Newark, DE, 19716, USA
| | - Ziqiang Qiu
- Department of Physics, University of California at Berkeley, Berkeley, CA, 94720, USA
| | - Can-Ming Hu
- Department of Physics and Astronomy, University of Manitoba, Winnipeg, MB, R3T 2N2, Canada
| | - Xixiang Zhang
- Physical Science and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia.
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5
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Komorowski PG, Cottam MG. Theory for magnetic impurity modes in two-dimensional van der Waals ferromagnetic films. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2024; 36:215801. [PMID: 38316060 DOI: 10.1088/1361-648x/ad2671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Accepted: 02/05/2024] [Indexed: 02/07/2024]
Abstract
A spin-wave analysis is developed to calculate the energies of the localized excitations occurring in two-dimensional ferromagnetic van der Waals monolayers when a substitutional magnetic impurity is introduced. The magnetic ions lie on a bipartite honeycomb lattice (similar to that for graphene) and the theory includes the effects of both Ising anisotropy and single-ion anisotropy to stabilize the magnetic ordering perpendicular to the atomic plane at low temperatures. A Dyson-equation formalism, together with the spin-dependent Green's functions derived for van der Waals monolayers, is employed to evaluate the existence conditions and energies for the impurity modes, which lie above the band of spin-wave states of the pure host material. For realistic parameter values it is found that typically two impurity modes may exist, depending on the spin quantum number for the magnetic impurity atom. Numerical applications are made to CrI3and Cr2Ge2Te6as the host materials.
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Affiliation(s)
- Peter G Komorowski
- Department of Physics and Astronomy, University of Western Ontario, London, Ontario N6A 3K7, Canada
| | - Michael G Cottam
- Department of Physics and Astronomy, University of Western Ontario, London, Ontario N6A 3K7, Canada
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6
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Hendriks F, Rojas-Lopez RR, Koopmans B, Guimarães MHD. Electric control of optically-induced magnetization dynamics in a van der Waals ferromagnetic semiconductor. Nat Commun 2024; 15:1298. [PMID: 38346955 PMCID: PMC10861592 DOI: 10.1038/s41467-024-45623-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Accepted: 01/30/2024] [Indexed: 02/15/2024] Open
Abstract
Electric control of magnetization dynamics in two-dimensional (2D) magnetic materials is an essential step for the development of novel spintronic nanodevices. Electrostatic gating has been shown to greatly affect the static magnetic properties of some van der Waals magnets, but the control over their magnetization dynamics is still largely unexplored. Here we show that the optically-induced magnetization dynamics in the van der Waals ferromagnet Cr2Ge2Te6 can be effectively controlled by electrostatic gates, with a one order of magnitude change in the precession amplitude and over 10% change in the internal effective field. In contrast to the purely thermally-induced mechanisms previously reported for 2D magnets, we find that coherent opto-magnetic phenomena play a major role in the excitation of magnetization dynamics in Cr2Ge2Te6. Our work sets the first steps towards electric control over the magnetization dynamics in 2D ferromagnetic semiconductors, demonstrating their potential for applications in ultrafast opto-magnonic devices.
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Affiliation(s)
- Freddie Hendriks
- Zernike Institute for Advanced Materials, University of Groningen, Groningen, The Netherlands
| | - Rafael R Rojas-Lopez
- Zernike Institute for Advanced Materials, University of Groningen, Groningen, The Netherlands
- Departamento de Física, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Bert Koopmans
- Department of Applied Physics, Eindhoven University of Technology, Eindhoven, The Netherlands
| | - Marcos H D Guimarães
- Zernike Institute for Advanced Materials, University of Groningen, Groningen, The Netherlands.
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7
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Bartram FM, Li M, Liu L, Xu Z, Wang Y, Che M, Li H, Wu Y, Xu Y, Zhang J, Yang S, Yang L. Real-time observation of magnetization and magnon dynamics in a two-dimensional topological antiferromagnet MnBi 2Te 4. Sci Bull (Beijing) 2023; 68:2734-2742. [PMID: 37863774 DOI: 10.1016/j.scib.2023.10.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 07/22/2023] [Accepted: 09/30/2023] [Indexed: 10/22/2023]
Abstract
Atomically thin van der Waals magnetic materials have not only provided a fertile playground to explore basic physics in the two-dimensional (2D) limit but also created vast opportunities for novel ultrafast functional devices. Here we systematically investigate ultrafast magnetization dynamics and spin wave dynamics in few-layer topological antiferromagnetic MnBi2Te4 crystals as a function of layer number, temperature, and magnetic field. We find laser-induced (de)magnetization processes can be used to accurately track the distinct magnetic states in different magnetic field regimes, including showing clear odd-even layer number effects. In addition, strongly field-dependent AFM magnon modes with tens of gigahertz frequencies are optically generated and directly observed in the time domain. Remarkably, we find that magnetization and magnon dynamics can be observed in not only the time-resolved magneto-optical Kerr effect but also the time resolved reflectivity, indicating strong correlation between the magnetic state and electronic structure. These measurements present the first comprehensive overview of ultrafast spin dynamics in this novel 2D antiferromagnet, paving the way for potential applications in 2D antiferromagnetic spintronics and magnonics as well as further studies of ultrafast control of both magnetization and topological quantum states.
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Affiliation(s)
- F Michael Bartram
- State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China; Department of Physics, University of Toronto, Toronto M5S 1A7, Canada
| | - Meng Li
- State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China
| | - Liangyang Liu
- State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China
| | - Zhiming Xu
- State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China
| | - Yongchao Wang
- Beijing Innovation Center for Future Chips, Tsinghua University, Beijing 100084, China
| | - Mengqian Che
- State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China
| | - Hao Li
- Tsinghua-Foxconn Nanotechnology Research Center, Department of Physics, Tsinghua University, Beijing 100084, China
| | - Yang Wu
- Tsinghua-Foxconn Nanotechnology Research Center, Department of Physics, Tsinghua University, Beijing 100084, China; College of Math and Physics, Beijing University of Chemical Technology, Beijing 100029, China
| | - Yong Xu
- State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China; Frontier Science Center for Quantum Information, Beijing 100084, China; Collaborative Innovation Center of Quantum Matter, Beijing 100084, China; RIKEN Center for Emergent Matter Science (CEMS), Wako, Saitama 351-0198, Japan
| | - Jinsong Zhang
- State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China; Frontier Science Center for Quantum Information, Beijing 100084, China; Hefei National Laboratory, Hefei 230088, China
| | - Shuo Yang
- State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China; Frontier Science Center for Quantum Information, Beijing 100084, China; Collaborative Innovation Center of Quantum Matter, Beijing 100084, China; Hefei National Laboratory, Hefei 230088, China
| | - Luyi Yang
- State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China; Department of Physics, University of Toronto, Toronto M5S 1A7, Canada; Frontier Science Center for Quantum Information, Beijing 100084, China; Collaborative Innovation Center of Quantum Matter, Beijing 100084, China.
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8
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Schulz F, Litzius K, Powalla L, Birch MT, Gallardo RA, Satheesh S, Weigand M, Scholz T, Lotsch BV, Schütz G, Burghard M, Wintz S. Direct Observation of Propagating Spin Waves in the 2D van der Waals Ferromagnet Fe 5GeTe 2. NANO LETTERS 2023; 23:10126-10131. [PMID: 37955345 PMCID: PMC10683057 DOI: 10.1021/acs.nanolett.3c02212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Revised: 11/01/2023] [Accepted: 11/03/2023] [Indexed: 11/14/2023]
Abstract
Magnetism in reduced dimensionalities is of great fundamental interest while also providing perspectives for applications of materials with novel functionalities. In particular, spin dynamics in two dimensions (2D) have become a focus of recent research. Here, we report the observation of coherent propagating spin-wave dynamics in a ∼30 nm thick flake of 2D van der Waals ferromagnet Fe5GeTe2 using X-ray microscopy. Both phase and amplitude information were obtained by direct imaging below TC for frequencies from 2.77 to 3.84 GHz, and the corresponding spin-wave wavelengths were measured to be between 1.5 and 0.5 μm. Thus, parts of the magnonic dispersion relation were determined despite a relatively high magnetic damping of the material. Numerically solving an analytic multilayer model allowed us to corroborate the experimental dispersion relation and predict the influence of changes in the saturation magnetization or interlayer coupling, which could be exploited in future applications by temperature control or stacking of 2D-heterostructures.
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Affiliation(s)
- Frank Schulz
- Max
Planck Institute for Intelligent Systems, Heisenbergstrasse 3, D-70569 Stuttgart, Germany
| | - Kai Litzius
- Max
Planck Institute for Intelligent Systems, Heisenbergstrasse 3, D-70569 Stuttgart, Germany
- Universität
Augsburg, D-86159 Augsburg, Germany
| | - Lukas Powalla
- Max
Planck Institute for Solid State Research, Heisenbergstrasse 1, D-70569 Stuttgart, Germany
| | - Max T. Birch
- Max
Planck Institute for Intelligent Systems, Heisenbergstrasse 3, D-70569 Stuttgart, Germany
- RIKEN
Center for Emergent Matter Science, JP-351-0198 Wako, Japan
| | - Rodolfo A. Gallardo
- Universidad
Técnica Federico Santa María, Avenida España 1680, 2390123 Valparaiso, Chile
| | - Sayooj Satheesh
- Max
Planck Institute for Solid State Research, Heisenbergstrasse 1, D-70569 Stuttgart, Germany
| | - Markus Weigand
- Max
Planck Institute for Intelligent Systems, Heisenbergstrasse 3, D-70569 Stuttgart, Germany
- Helmholtz-Zentrum
Berlin für Materialien und Energie GmbH, Hahn-Meitner-Platz 1, D-14109 Berlin, Germany
| | - Tanja Scholz
- Max
Planck Institute for Solid State Research, Heisenbergstrasse 1, D-70569 Stuttgart, Germany
| | - Bettina V. Lotsch
- Max
Planck Institute for Solid State Research, Heisenbergstrasse 1, D-70569 Stuttgart, Germany
| | - Gisela Schütz
- Max
Planck Institute for Intelligent Systems, Heisenbergstrasse 3, D-70569 Stuttgart, Germany
| | - Marko Burghard
- Max
Planck Institute for Solid State Research, Heisenbergstrasse 1, D-70569 Stuttgart, Germany
| | - Sebastian Wintz
- Max
Planck Institute for Intelligent Systems, Heisenbergstrasse 3, D-70569 Stuttgart, Germany
- Helmholtz-Zentrum
Berlin für Materialien und Energie GmbH, Hahn-Meitner-Platz 1, D-14109 Berlin, Germany
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9
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Liu S, Malik IA, Zhang VL, Yu T. Lightning the Spin: Harnessing the Potential of 2D Magnets in Opto-Spintronics. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023:e2306920. [PMID: 37905890 DOI: 10.1002/adma.202306920] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Revised: 09/20/2023] [Indexed: 11/02/2023]
Abstract
Since the emergence of 2D magnets in 2017, the diversity of these materials has greatly expanded. Their 2D nature (atomic-scale thickness) endows these magnets with strong magnetic anisotropy, layer-dependent and switchable magnetic order, and quantum-confined quasiparticles, which distinguish them from conventional 3D magnetic materials. Moreover, the 2D geometry facilitates light incidence for opto-spintronic applications and potential on-chip integration. In analogy to optoelectronics based on optical-electronic interactions, opto-spintronics use light-spin interactions to process spin information stored in the solid state. In this review, opto-spintronics is divided into three types with respect to the wavelengths of radiation interacting with 2D magnets: 1) GHz (microwave) to THz (mid-infrared), 2) visible, and 3) UV to X-rays. It is focused on the recent research advancements on the newly discovered mechanisms of light-spin interactions in 2D magnets and introduces the potential design of novel opto-spintronic applications based on these interactions.
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Affiliation(s)
- Sheng Liu
- School of Physics and Technology, Wuhan University, Wuhan, 430072, P. R. China
| | | | - Vanessa Li Zhang
- School of Physics and Technology, Wuhan University, Wuhan, 430072, P. R. China
| | - Ting Yu
- School of Physics and Technology, Wuhan University, Wuhan, 430072, P. R. China
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10
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Jiao C, Pei S, Wu S, Wang Z, Xia J. Tuning and exploiting interlayer coupling in two-dimensional van der Waals heterostructures. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2023; 86:114503. [PMID: 37774692 DOI: 10.1088/1361-6633/acfe89] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Accepted: 09/29/2023] [Indexed: 10/01/2023]
Abstract
Two-dimensional (2D) layered materials can stack into new material systems, with van der Waals (vdW) interaction between the adjacent constituent layers. This stacking process of 2D atomic layers creates a new degree of freedom-interlayer interface between two adjacent layers-that can be independently studied and tuned from the intralayer degree of freedom. In such heterostructures (HSs), the physical properties are largely determined by the vdW interaction between the individual layers,i.e.interlayer coupling, which can be effectively tuned by a number of means. In this review, we summarize and discuss a number of such approaches, including stacking order, electric field, intercalation, and pressure, with both their experimental demonstrations and theoretical predictions. A comprehensive overview of the modulation on structural, optical, electrical, and magnetic properties by these four approaches are also presented. We conclude this review by discussing several prospective research directions in 2D HSs field, including fundamental physics study, property tuning techniques, and future applications.
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Affiliation(s)
- Chenyin Jiao
- Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Chengdu 610054, People's Republic of China
| | - Shenghai Pei
- Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Chengdu 610054, People's Republic of China
| | - Song Wu
- Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Chengdu 610054, People's Republic of China
| | - Zenghui Wang
- Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Chengdu 610054, People's Republic of China
| | - Juan Xia
- Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Chengdu 610054, People's Republic of China
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11
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Man P, Huang L, Zhao J, Ly TH. Ferroic Phases in Two-Dimensional Materials. Chem Rev 2023; 123:10990-11046. [PMID: 37672768 DOI: 10.1021/acs.chemrev.3c00170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/08/2023]
Abstract
Two-dimensional (2D) ferroics, namely ferroelectric, ferromagnetic, and ferroelastic materials, are attracting rising interest due to their fascinating physical properties and promising functional applications. A variety of 2D ferroic phases, as well as 2D multiferroics and the novel 2D ferrovalleytronics/ferrotoroidics, have been recently predicted by theory, even down to the single atomic layers. Meanwhile, some of them have already been experimentally verified. In addition to the intrinsic 2D ferroics, appropriate stacking, doping, and defects can also artificially regulate the ferroic phases of 2D materials. Correspondingly, ferroic ordering in 2D materials exhibits enormous potential for future high density memory devices, energy conversion devices, and sensing devices, among other applications. In this paper, the recent research progresses on 2D ferroic phases are comprehensively reviewed, with emphasis on chemistry and structural origin of the ferroic properties. In addition, the promising applications of the 2D ferroics for information storage, optoelectronics, and sensing are also briefly discussed. Finally, we envisioned a few possible pathways for the future 2D ferroics research and development. This comprehensive overview on the 2D ferroic phases can provide an atlas for this field and facilitate further exploration of the intriguing new materials and physical phenomena, which will generate tremendous impact on future functional materials and devices.
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Affiliation(s)
- Ping Man
- Department of Chemistry and Center of Super-Diamond & Advanced Films (COSDAF), City University of Hong Kong, Kowloon, Hong Kong 999077, P. R. China
- City University of Hong Kong Shenzhen Research Institute, Shenzhen 518057, P. R. China
| | - Lingli Huang
- Department of Chemistry and Center of Super-Diamond & Advanced Films (COSDAF), City University of Hong Kong, Kowloon, Hong Kong 999077, P. R. China
- City University of Hong Kong Shenzhen Research Institute, Shenzhen 518057, P. R. China
| | - Jiong Zhao
- Department of Applied Physics, The Hong Kong Polytechnic University, Kowloon, Hong Kong 999077, P. R. China
- The Hong Kong Polytechnic University Shenzhen Research Institute, Shenzhen 518057, P. R. China
| | - Thuc Hue Ly
- Department of Chemistry and Center of Super-Diamond & Advanced Films (COSDAF), City University of Hong Kong, Kowloon, Hong Kong 999077, P. R. China
- City University of Hong Kong Shenzhen Research Institute, Shenzhen 518057, P. R. China
- Department of Chemistry and State Key Laboratory of Marine Pollution, City University of Hong Kong, Kowloon, Hong Kong 999077, P. R. China
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12
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Teh S, Jeng HT. Magnetoelastic and Magnetoelectric Coupling in Two-Dimensional Nitride MXenes: A Density Functional Theory Study. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:2644. [PMID: 37836286 PMCID: PMC10574495 DOI: 10.3390/nano13192644] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 09/22/2023] [Accepted: 09/23/2023] [Indexed: 10/15/2023]
Abstract
Two-dimensional multiferroic (2D) materials have garnered significant attention due to their potential in high-density, low-power multistate storage and spintronics applications. MXenes, a class of 2D transition metal carbides and nitrides, were first discovered in 2011, and have become the focus of research in various disciplines. Our study, utilizing first-principles calculations, examines the lattice structures, and electronic and magnetic properties of nitride MXenes with intrinsic band gaps, including V2NF2, V2NO2, Cr2NF2, Mo2NO2, Mo2NF2, and Mn2NO2. These nitride MXenes exhibit orbital ordering, and in some cases the orbital ordering induces magnetoelastic coupling or magnetoelectric coupling. Most notably, Cr2NF2 is a ferroelastic material with a spiral magnetic ordered phase, and the spiral magnetization propagation vector is coupled with the direction of ferroelastic strain. The ferroelectric phase can exist as an excited state in V2NO2, Cr2NF2, and Mo2NF2, with their magnetic order being coupled with polar displacements through orbital ordering. Our results also suggest that similar magnetoelectric coupling effects persist in the Janus MXenes V8N4O7F, Cr8N4F7O, and Mo8N4F7O. Remarkably, different phases of Mo8N4F7O, characterized by orbital ordering rearrangements, can be switched by applying external strain or an external electric field. Overall, our theoretical findings suggest that nitride MXenes hold promise as 2D multiferroic materials.
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Affiliation(s)
- Sukhito Teh
- Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Horng-Tay Jeng
- Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan
- Institute of Physics, Academia Sinica, Taipei 11529, Taiwan
- Physics Division, National Center for Theoretical Sciences, Taipei 10617, Taiwan
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13
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Cui J, Boström EV, Ozerov M, Wu F, Jiang Q, Chu JH, Li C, Liu F, Xu X, Rubio A, Zhang Q. Chirality selective magnon-phonon hybridization and magnon-induced chiral phonons in a layered zigzag antiferromagnet. Nat Commun 2023; 14:3396. [PMID: 37296106 DOI: 10.1038/s41467-023-39123-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Accepted: 05/30/2023] [Indexed: 06/12/2023] Open
Abstract
Two-dimensional (2D) magnetic systems possess versatile magnetic order and can host tunable magnons carrying spin angular momenta. Recent advances show angular momentum can also be carried by lattice vibrations in the form of chiral phonons. However, the interplay between magnons and chiral phonons as well as the details of chiral phonon formation in a magnetic system are yet to be explored. Here, we report the observation of magnon-induced chiral phonons and chirality selective magnon-phonon hybridization in a layered zigzag antiferromagnet (AFM) FePSe3. With a combination of magneto-infrared and magneto-Raman spectroscopy, we observe chiral magnon polarons (chiMP), the new hybridized quasiparticles, at zero magnetic field. The hybridization gap reaches 0.25 meV and survives down to the quadrilayer limit. Via first principle calculations, we uncover a coherent coupling between AFM magnons and chiral phonons with parallel angular momenta, which arises from the underlying phonon and space group symmetries. This coupling lifts the chiral phonon degeneracy and gives rise to an unusual Raman circular polarization of the chiMP branches. The observation of coherent chiral spin-lattice excitations at zero magnetic field paves the way for angular momentum-based hybrid phononic and magnonic devices.
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Affiliation(s)
- Jun Cui
- National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, 210093, Nanjing, China
| | - Emil Viñas Boström
- Max Planck Institute for the Structure and Dynamics of Matter, Luruper Chaussee 149, 22761, Hamburg, Germany
| | - Mykhaylo Ozerov
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL, 32310, USA.
| | - Fangliang Wu
- National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, 210093, Nanjing, China
| | - Qianni Jiang
- Department of Physics, University of Washington, Seattle, WA, 98195, USA
| | - Jiun-Haw Chu
- Department of Physics, University of Washington, Seattle, WA, 98195, USA
| | - Changcun Li
- School of Optoelectronic Science and Engineering, University of Electronic Science and Technology of China, 611731, Chengdu, China
| | - Fucai Liu
- School of Optoelectronic Science and Engineering, University of Electronic Science and Technology of China, 611731, Chengdu, China
| | - Xiaodong Xu
- Department of Physics, University of Washington, Seattle, WA, 98195, USA
- Department of Materials Science and Engineering, University of Washington, Seattle, WA, 98195, USA
| | - Angel Rubio
- Max Planck Institute for the Structure and Dynamics of Matter, Luruper Chaussee 149, 22761, Hamburg, Germany.
- Center for Computational Quantum Physics, The Flatiron Institute, New York, NY, 10010, USA.
| | - Qi Zhang
- National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, 210093, Nanjing, China.
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14
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Zollitsch CW, Khan S, Nam VTT, Verzhbitskiy IA, Sagkovits D, O'Sullivan J, Kennedy OW, Strungaru M, Santos EJG, Morton JJL, Eda G, Kurebayashi H. Probing spin dynamics of ultra-thin van der Waals magnets via photon-magnon coupling. Nat Commun 2023; 14:2619. [PMID: 37147370 PMCID: PMC10163026 DOI: 10.1038/s41467-023-38322-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Accepted: 04/25/2023] [Indexed: 05/07/2023] Open
Abstract
Layered van der Waals (vdW) magnets can maintain a magnetic order even down to the single-layer regime and hold promise for integrated spintronic devices. While the magnetic ground state of vdW magnets was extensively studied, key parameters of spin dynamics, like the Gilbert damping, crucial for designing ultra-fast spintronic devices, remains largely unexplored. Despite recent studies by optical excitation and detection, achieving spin wave control with microwaves is highly desirable, as modern integrated information technologies predominantly are operated with these. The intrinsically small numbers of spins, however, poses a major challenge to this. Here, we present a hybrid approach to detect spin dynamics mediated by photon-magnon coupling between high-Q superconducting resonators and ultra-thin flakes of Cr2Ge2Te6 (CGT) as thin as 11 nm. We test and benchmark our technique with 23 individual CGT flakes and extract an upper limit for the Gilbert damping parameter. These results are crucial in designing on-chip integrated circuits using vdW magnets and offer prospects for probing spin dynamics of monolayer vdW magnets.
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Affiliation(s)
- Christoph W Zollitsch
- London Centre for Nanotechnology, University College London, 17-19 Gordon Street, London, WCH1 0AH, UK.
| | - Safe Khan
- London Centre for Nanotechnology, University College London, 17-19 Gordon Street, London, WCH1 0AH, UK
| | - Vu Thanh Trung Nam
- Department of Physics, Faculty of Science, National University of Singapore, 2 Science Drive 3, Singapore, 117542, Singapore
| | - Ivan A Verzhbitskiy
- Department of Physics, Faculty of Science, National University of Singapore, 2 Science Drive 3, Singapore, 117542, Singapore
| | - Dimitrios Sagkovits
- London Centre for Nanotechnology, University College London, 17-19 Gordon Street, London, WCH1 0AH, UK
- National Physical Laboratory, Hampton Road, Teddington, TW11 0LW, UK
| | - James O'Sullivan
- London Centre for Nanotechnology, University College London, 17-19 Gordon Street, London, WCH1 0AH, UK
| | - Oscar W Kennedy
- London Centre for Nanotechnology, University College London, 17-19 Gordon Street, London, WCH1 0AH, UK
| | - Mara Strungaru
- Institute for Condensed Matter Physics and Complex Systems, School of Physics and Astronomy, The University of Edinburgh, Edinburgh, EH9 3FD, UK
| | - Elton J G Santos
- Institute for Condensed Matter Physics and Complex Systems, School of Physics and Astronomy, The University of Edinburgh, Edinburgh, EH9 3FD, UK
- Higgs Centre for Theoretical Physics, The University of Edinburgh, Edinburgh, EH9 3FD, UK
| | - John J L Morton
- London Centre for Nanotechnology, University College London, 17-19 Gordon Street, London, WCH1 0AH, UK
- Department of Electronic & Electrical Engineering, UCL, London, WC1E 7JE, UK
| | - Goki Eda
- Department of Physics, Faculty of Science, National University of Singapore, 2 Science Drive 3, Singapore, 117542, Singapore
- Centre for Advanced 2D Materials, National University of Singapore, 6 Science Drive 2, Singapore, 117546, Singapore
- Department of Chemistry, Faculty of Science, National University of Singapore, 3 Science Drive 3, Singapore, 117543, Singapore
| | - Hidekazu Kurebayashi
- London Centre for Nanotechnology, University College London, 17-19 Gordon Street, London, WCH1 0AH, UK
- Department of Electronic & Electrical Engineering, UCL, London, WC1E 7JE, UK
- WPI Advanced Institute for Materials Research, Tohoku University, 2-1-1, Katahira, Sendai, 980- 8577, Japan
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15
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Qi S, Chen D, Chen K, Liu J, Chen G, Luo B, Cui H, Jia L, Li J, Huang M, Song Y, Han S, Tong L, Yu P, Liu Y, Wu H, Wu S, Xiao J, Shindou R, Xie XC, Chen JH. Giant electrically tunable magnon transport anisotropy in a van der Waals antiferromagnetic insulator. Nat Commun 2023; 14:2526. [PMID: 37130859 PMCID: PMC10154397 DOI: 10.1038/s41467-023-38172-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2022] [Accepted: 04/19/2023] [Indexed: 05/04/2023] Open
Abstract
Anisotropy is a manifestation of lowered symmetry in material systems that have profound fundamental and technological implications. For van der Waals magnets, the two-dimensional (2D) nature greatly enhances the effect of in-plane anisotropy. However, electrical manipulation of such anisotropy as well as demonstration of possible applications remains elusive. In particular, in-situ electrical modulation of anisotropy in spin transport, vital for spintronics applications, has yet to be achieved. Here, we realized giant electrically tunable anisotropy in the transport of second harmonic thermal magnons (SHM) in van der Waals anti-ferromagnetic insulator CrPS4 with the application of modest gate current. Theoretical modeling found that 2D anisotropic spin Seebeck effect is the key to the electrical tunability. Making use of such large and tunable anisotropy, we demonstrated multi-bit read-only memories (ROMs) where information is inscribed by the anisotropy of magnon transport in CrPS4. Our result unveils the potential of anisotropic van der Waals magnons for information storage and processing.
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Affiliation(s)
- Shaomian Qi
- International Center of Quantum Materials, School of Physics, Peking University, Beijing, China
| | - Di Chen
- Beijing Academy of Quantum Information Sciences, Beijing, China
| | - Kangyao Chen
- International Center of Quantum Materials, School of Physics, Peking University, Beijing, China
| | - Jianqiao Liu
- International Center of Quantum Materials, School of Physics, Peking University, Beijing, China
| | - Guangyi Chen
- International Center of Quantum Materials, School of Physics, Peking University, Beijing, China
| | - Bingcheng Luo
- International Center of Quantum Materials, School of Physics, Peking University, Beijing, China
| | - Hang Cui
- International Center of Quantum Materials, School of Physics, Peking University, Beijing, China
| | - Linhao Jia
- International Center of Quantum Materials, School of Physics, Peking University, Beijing, China
- Beijing Academy of Quantum Information Sciences, Beijing, China
| | - Jiankun Li
- Beijing Academy of Quantum Information Sciences, Beijing, China
| | - Miaoling Huang
- Beijing Academy of Quantum Information Sciences, Beijing, China
| | - Yuanjun Song
- Beijing Academy of Quantum Information Sciences, Beijing, China
| | - Shiyi Han
- College of Chemistry and Molecular Engineering, Peking University, Beijing, China
| | - Lianming Tong
- College of Chemistry and Molecular Engineering, Peking University, Beijing, China
| | - Peng Yu
- State Key Laboratory of Optoelectronic Materials and Technologies, School of Materials Science and Engineering, Sun Yat-sen University, Guangzhou, China
| | - Yi Liu
- Center for Advanced Quantum Studies and Department of Physics, Beijing Normal University, Beijing, China
| | - Hongyu Wu
- Key Laboratory of Magnetic Materials and Devices, Zhejiang Province Key Laboratory of Magnetic Materials and Application Technology, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, China
| | - Shiwei Wu
- Department of Physics and State Key Laboratory of Surface Physics, Fudan University, Shanghai, China
| | - Jiang Xiao
- Department of Physics and State Key Laboratory of Surface Physics, Fudan University, Shanghai, China
| | - Ryuichi Shindou
- International Center of Quantum Materials, School of Physics, Peking University, Beijing, China
| | - X C Xie
- International Center of Quantum Materials, School of Physics, Peking University, Beijing, China
- Hefei National Laboratory, Hefei, China
| | - Jian-Hao Chen
- International Center of Quantum Materials, School of Physics, Peking University, Beijing, China.
- Beijing Academy of Quantum Information Sciences, Beijing, China.
- Hefei National Laboratory, Hefei, China.
- Key Laboratory for the Physics and Chemistry of Nanodevices, Peking University, Beijing, China.
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16
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Wang H, Lu H, Guo Z, Li A, Wu P, Li J, Xie W, Sun Z, Li P, Damas H, Friedel AM, Migot S, Ghanbaja J, Moreau L, Fagot-Revurat Y, Petit-Watelot S, Hauet T, Robertson J, Mangin S, Zhao W, Nie T. Interfacial engineering of ferromagnetism in wafer-scale van der Waals Fe 4GeTe 2 far above room temperature. Nat Commun 2023; 14:2483. [PMID: 37120587 PMCID: PMC10148834 DOI: 10.1038/s41467-023-37917-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2022] [Accepted: 04/05/2023] [Indexed: 05/01/2023] Open
Abstract
Despite recent advances in exfoliated vdW ferromagnets, the widespread application of 2D magnetism requires a Curie temperature (Tc) above room temperature as well as a stable and controllable magnetic anisotropy. Here we demonstrate a large-scale iron-based vdW material Fe4GeTe2 with the Tc reaching ~530 K. We confirmed the high-temperature ferromagnetism by multiple characterizations. Theoretical calculations suggested that the interface-induced right shift of the localized states for unpaired Fe d electrons is the reason for the enhanced Tc, which was confirmed by ultraviolet photoelectron spectroscopy. Moreover, by precisely tailoring Fe concentration we achieved arbitrary control of magnetic anisotropy between out-of-plane and in-plane without inducing any phase disorders. Our finding sheds light on the high potential of Fe4GeTe2 in spintronics, which may open opportunities for room-temperature application of all-vdW spintronic devices.
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Affiliation(s)
- Hangtian Wang
- Fert Beijing Institute, MIIT Key Laboratory of Spintronics, School of Integrated Circuit Science and Engineering, Beihang University, Beijing, 100191, China
- Universite de Lorraine, Institut Jean Lamour, UMR CNRS 7198, Nancy, France
| | - Haichang Lu
- Fert Beijing Institute, MIIT Key Laboratory of Spintronics, School of Integrated Circuit Science and Engineering, Beihang University, Beijing, 100191, China.
- Engineering Department, Cambridge University, Cambridge, CB2 1PZ, UK.
| | - Zongxia Guo
- Fert Beijing Institute, MIIT Key Laboratory of Spintronics, School of Integrated Circuit Science and Engineering, Beihang University, Beijing, 100191, China
- Universite de Lorraine, Institut Jean Lamour, UMR CNRS 7198, Nancy, France
| | - Ang Li
- Fert Beijing Institute, MIIT Key Laboratory of Spintronics, School of Integrated Circuit Science and Engineering, Beihang University, Beijing, 100191, China
| | - Peichen Wu
- Fert Beijing Institute, MIIT Key Laboratory of Spintronics, School of Integrated Circuit Science and Engineering, Beihang University, Beijing, 100191, China
| | - Jing Li
- Fert Beijing Institute, MIIT Key Laboratory of Spintronics, School of Integrated Circuit Science and Engineering, Beihang University, Beijing, 100191, China
| | - Weiran Xie
- Fert Beijing Institute, MIIT Key Laboratory of Spintronics, School of Integrated Circuit Science and Engineering, Beihang University, Beijing, 100191, China
| | - Zhimei Sun
- School of Materials Science and Engineering, Beihang University, Beijing, 100191, China
| | - Peng Li
- Department of Electrical and Computer Engineering, Auburn University, Auburn, AL, USA
| | - Héloïse Damas
- Universite de Lorraine, Institut Jean Lamour, UMR CNRS 7198, Nancy, France
| | - Anna Maria Friedel
- Universite de Lorraine, Institut Jean Lamour, UMR CNRS 7198, Nancy, France
- Fachbereich Physik and Landesforschungszentrum OPTIMAS, Technische Universität Kaiserslautern, 67663, Kaiserslautern, Germany
| | - Sylvie Migot
- Universite de Lorraine, Institut Jean Lamour, UMR CNRS 7198, Nancy, France
| | - Jaafar Ghanbaja
- Universite de Lorraine, Institut Jean Lamour, UMR CNRS 7198, Nancy, France
| | - Luc Moreau
- Universite de Lorraine, Institut Jean Lamour, UMR CNRS 7198, Nancy, France
| | | | | | - Thomas Hauet
- Universite de Lorraine, Institut Jean Lamour, UMR CNRS 7198, Nancy, France
| | - John Robertson
- Engineering Department, Cambridge University, Cambridge, CB2 1PZ, UK
| | - Stéphane Mangin
- Universite de Lorraine, Institut Jean Lamour, UMR CNRS 7198, Nancy, France.
| | - Weisheng Zhao
- Fert Beijing Institute, MIIT Key Laboratory of Spintronics, School of Integrated Circuit Science and Engineering, Beihang University, Beijing, 100191, China.
| | - Tianxiao Nie
- Fert Beijing Institute, MIIT Key Laboratory of Spintronics, School of Integrated Circuit Science and Engineering, Beihang University, Beijing, 100191, China.
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17
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Comstock AH, Chou CT, Wang Z, Wang T, Song R, Sklenar J, Amassian A, Zhang W, Lu H, Liu L, Beard MC, Sun D. Hybrid magnonics in hybrid perovskite antiferromagnets. Nat Commun 2023; 14:1834. [PMID: 37005408 PMCID: PMC10067936 DOI: 10.1038/s41467-023-37505-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Accepted: 03/20/2023] [Indexed: 04/04/2023] Open
Abstract
Hybrid magnonic systems are a newcomer for pursuing coherent information processing owing to their rich quantum engineering functionalities. One prototypical example is hybrid magnonics in antiferromagnets with an easy-plane anisotropy that resembles a quantum-mechanically mixed two-level spin system through the coupling of acoustic and optical magnons. Generally, the coupling between these orthogonal modes is forbidden due to their opposite parity. Here we show that the Dzyaloshinskii-Moriya-Interaction (DMI), a chiral antisymmetric interaction that occurs in magnetic systems with low symmetry, can lift this restriction. We report that layered hybrid perovskite antiferromagnets with an interlayer DMI can lead to a strong intrinsic magnon-magnon coupling strength up to 0.24 GHz, which is four times greater than the dissipation rates of the acoustic/optical modes. Our work shows that the DMI in these hybrid antiferromagnets holds promise for leveraging magnon-magnon coupling by harnessing symmetry breaking in a highly tunable, solution-processable layered magnetic platform.
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Affiliation(s)
- Andrew H Comstock
- Department of Physics, North Carolina State University, Raleigh, NC, 27695, USA
- Organic and Carbon Electronics Laboratory (ORACEL), North Carolina State University, Raleigh, NC, 27695, USA
| | - Chung-Tao Chou
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Zhiyu Wang
- Department of Chemistry and Energy Institute, The Hong Kong University of Science and Technology, Kowloon, 999077, Hong Kong (SAR), China
| | - Tonghui Wang
- Organic and Carbon Electronics Laboratory (ORACEL), North Carolina State University, Raleigh, NC, 27695, USA
- Department of Materials Science and Engineering, North Carolina State University, Raleigh, NC, 27695, USA
| | - Ruyi Song
- Department of Mechanical Engineering and Material Science, Duke University, Durham, NC, 27708, USA
| | - Joseph Sklenar
- Department of Physics and Astronomy, Wayne State University, Detroit, MI, 48202, USA
| | - Aram Amassian
- Organic and Carbon Electronics Laboratory (ORACEL), North Carolina State University, Raleigh, NC, 27695, USA
- Department of Materials Science and Engineering, North Carolina State University, Raleigh, NC, 27695, USA
| | - Wei Zhang
- Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Haipeng Lu
- Department of Chemistry and Energy Institute, The Hong Kong University of Science and Technology, Kowloon, 999077, Hong Kong (SAR), China.
- Chemistry and Nanoscience Center, National Renewable Energy Laboratory, Golden, CO, 80401, USA.
| | - Luqiao Liu
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
| | - Matthew C Beard
- Chemistry and Nanoscience Center, National Renewable Energy Laboratory, Golden, CO, 80401, USA.
| | - Dali Sun
- Department of Physics, North Carolina State University, Raleigh, NC, 27695, USA.
- Organic and Carbon Electronics Laboratory (ORACEL), North Carolina State University, Raleigh, NC, 27695, USA.
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18
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Wang X, Shang Z, Zhang C, Kang J, Liu T, Wang X, Chen S, Liu H, Tang W, Zeng YJ, Guo J, Cheng Z, Liu L, Pan D, Tong S, Wu B, Xie Y, Wang G, Deng J, Zhai T, Deng HX, Hong J, Zhao J. Electrical and magnetic anisotropies in van der Waals multiferroic CuCrP 2S 6. Nat Commun 2023; 14:840. [PMID: 36792610 PMCID: PMC9931707 DOI: 10.1038/s41467-023-36512-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Accepted: 02/06/2023] [Indexed: 02/17/2023] Open
Abstract
Multiferroic materials have great potential in non-volatile devices for low-power and ultra-high density information storage, owing to their unique characteristic of coexisting ferroelectric and ferromagnetic orders. The effective manipulation of their intrinsic anisotropy makes it promising to control multiple degrees of the storage "medium". Here, we have discovered intriguing in-plane electrical and magnetic anisotropies in van der Waals (vdW) multiferroic CuCrP2S6. The uniaxial anisotropies of current rectifications, magnetic properties and magnon modes are demonstrated and manipulated by electric direction/polarity, temperature variation and magnetic field. More important, we have discovered the spin-flop transition corresponding to specific resonance modes, and determined the anisotropy parameters by consistent model fittings and theoretical calculations. Our work provides in-depth investigation and quantitative analysis of electrical and magnetic anisotropies with the same easy axis in vdW multiferroics, which will stimulate potential device applications of artificial bionic synapses, multi-terminal spintronic chips and magnetoelectric devices.
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Affiliation(s)
- Xiaolei Wang
- Department of Physics and Optoelectronic Engineering, Faculty of Science, Beijing University of Technology, Beijing, 100124, China.
| | - Zixuan Shang
- grid.28703.3e0000 0000 9040 3743Department of Physics and Optoelectronic Engineering, Faculty of Science, Beijing University of Technology, Beijing, 100124 China
| | - Chen Zhang
- grid.9227.e0000000119573309State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083 China
| | - Jiaqian Kang
- grid.43555.320000 0000 8841 6246School of Aerospace Engineering, Beijing Institute of Technology, Beijing, 100081 China
| | - Tao Liu
- grid.54549.390000 0004 0369 4060National Engineering Research Center of Electromagnetic Radiation Control Materials, University of Electronic Science and Technology of China, Chengdu, 610054 China
| | - Xueyun Wang
- School of Aerospace Engineering, Beijing Institute of Technology, Beijing, 100081, China.
| | - Siliang Chen
- grid.19373.3f0000 0001 0193 3564Guangdong Provincial Key Laboratory of Semiconductor, Optoelectronic Materials and Intelligent Photonic Systems, School of Science, Harbin Institute of Technology (Shenzhen), Shenzhen, 518055 China
| | - Haoliang Liu
- Guangdong Provincial Key Laboratory of Semiconductor, Optoelectronic Materials and Intelligent Photonic Systems, School of Science, Harbin Institute of Technology (Shenzhen), Shenzhen, 518055, China.
| | - Wei Tang
- grid.263488.30000 0001 0472 9649Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen, 518060 China
| | - Yu-Jia Zeng
- Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen, 518060, China.
| | - Jianfeng Guo
- grid.24539.390000 0004 0368 8103Department of Physics and Beijing Key Laboratory of Opto-electronic Functional Materials & Micro-nano Devices, Renmin University of China, Beijing, 100872 China
| | - Zhihai Cheng
- grid.24539.390000 0004 0368 8103Department of Physics and Beijing Key Laboratory of Opto-electronic Functional Materials & Micro-nano Devices, Renmin University of China, Beijing, 100872 China
| | - Lei Liu
- grid.9227.e0000000119573309State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083 China
| | - Dong Pan
- grid.9227.e0000000119573309State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083 China
| | - Shucheng Tong
- grid.9227.e0000000119573309State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083 China
| | - Bo Wu
- grid.28703.3e0000 0000 9040 3743Key Laboratory of Optoelectronics Technology Ministry of Education, Beijing University of Technology, Beijing, 100124 China
| | - Yiyang Xie
- grid.28703.3e0000 0000 9040 3743Key Laboratory of Optoelectronics Technology Ministry of Education, Beijing University of Technology, Beijing, 100124 China
| | - Guangcheng Wang
- grid.28703.3e0000 0000 9040 3743Department of Physics and Optoelectronic Engineering, Faculty of Science, Beijing University of Technology, Beijing, 100124 China
| | - Jinxiang Deng
- grid.28703.3e0000 0000 9040 3743Department of Physics and Optoelectronic Engineering, Faculty of Science, Beijing University of Technology, Beijing, 100124 China
| | - Tianrui Zhai
- grid.28703.3e0000 0000 9040 3743Department of Physics and Optoelectronic Engineering, Faculty of Science, Beijing University of Technology, Beijing, 100124 China
| | - Hui-Xiong Deng
- grid.9227.e0000000119573309State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083 China
| | - Jiawang Hong
- grid.43555.320000 0000 8841 6246School of Aerospace Engineering, Beijing Institute of Technology, Beijing, 100081 China
| | - Jianhua Zhao
- grid.9227.e0000000119573309State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083 China
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19
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Diederich GM, Cenker J, Ren Y, Fonseca J, Chica DG, Bae YJ, Zhu X, Roy X, Cao T, Xiao D, Xu X. Tunable interaction between excitons and hybridized magnons in a layered semiconductor. NATURE NANOTECHNOLOGY 2023; 18:23-28. [PMID: 36577852 DOI: 10.1038/s41565-022-01259-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Accepted: 10/10/2022] [Indexed: 06/17/2023]
Abstract
The interaction between distinct excitations in solids is of both fundamental interest and technological importance. One such interaction is the coupling between an exciton, a Coulomb bound electron-hole pair, and a magnon, a collective spin excitation. The recent emergence of van der Waals magnetic semiconductors1 provides a platform to explore these exciton-magnon interactions and their fundamental properties, such as strong correlation2, as well as their photospintronic and quantum transduction3 applications. Here we demonstrate the precise control of coherent exciton-magnon interactions in the layered magnetic semiconductor CrSBr. We varied the direction of an applied magnetic field relative to the crystal axes, and thus the rotational symmetry of the magnetic system4. Thereby, we tuned not only the exciton coupling to the bright magnon, but also to an optically dark mode via magnon-magnon hybridization. We further modulated the exciton-magnon coupling and the associated magnon dispersion curves through the application of uniaxial strain. At a critical strain, a dispersionless dark magnon band emerged. Our results demonstrate an unprecedented level of control of the opto-mechanical-magnonic coupling, and a step towards the predictable and controllable implementation of hybrid quantum magnonics5-11.
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Affiliation(s)
- Geoffrey M Diederich
- Intelligence Community Postdoctoral Research Fellowship Program, University of Washington, Seattle, WA, USA
- Department of Physics, University of Washington, Seattle, WA, USA
| | - John Cenker
- Department of Physics, University of Washington, Seattle, WA, USA
| | - Yafei Ren
- Department of Materials Science and Engineering, University of Washington, Seattle, WA, USA
| | - Jordan Fonseca
- Department of Physics, University of Washington, Seattle, WA, USA
| | - Daniel G Chica
- Department of Chemistry, Columbia University, New York, NY, USA
| | - Youn Jue Bae
- Department of Chemistry, Columbia University, New York, NY, USA
| | - Xiaoyang Zhu
- Department of Chemistry, Columbia University, New York, NY, USA
| | - Xavier Roy
- Department of Chemistry, Columbia University, New York, NY, USA
| | - Ting Cao
- Department of Materials Science and Engineering, University of Washington, Seattle, WA, USA
| | - Di Xiao
- Department of Physics, University of Washington, Seattle, WA, USA.
- Department of Materials Science and Engineering, University of Washington, Seattle, WA, USA.
| | - Xiaodong Xu
- Department of Physics, University of Washington, Seattle, WA, USA.
- Department of Materials Science and Engineering, University of Washington, Seattle, WA, USA.
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20
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Jiang H, Zang Z, Wang X, Que H, Wang L, Si K, Zhang P, Ye Y, Gong Y. Thickness-Tunable Growth of Composition-Controllable Two-Dimensional Fe xGeTe 2. NANO LETTERS 2022; 22:9477-9484. [PMID: 36383484 DOI: 10.1021/acs.nanolett.2c03562] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Two-dimensional (2D) magnetic materials provide an ideal platform for investigating novel magnetism and spin behavior in low-dimensional systems while being restricted by the deficiency of accurate bottom-up synthesis. To overcome this difficulty, a facile and universal flux-assisted growth (FAG) method is proposed to synthesize the multicomponent FexGeTe2 (x = 3-5) with different Fe contents and even alloyed with hetero metal atoms. This one-to-one method ensures the stoichiometry consistency from the FexGeTe2 and MyFe5-yGeTe2 (M = Co, Ni) bulk crystal precursors to the 2D nanosheets, with controllable composition. Tuning the growth temperatures can provide thickness-tunable products. Changeable magnetic properties of FexGeTe2 and alloyed CoyFe5-yGeTe2 are substantiated by the superconducting quantum interference device and reflective magnetic circular dichroism. This method generates thickness-tunable high-crystallinity FexGeTe2 samples without phase separation and exhibits a high tolerance to different substrates and a large temperature window, providing a new avenue to synthesize and explore such multicomponent 2D magnets and even the alloyed ones.
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Affiliation(s)
- Huaning Jiang
- School of Materials Science and Engineering, Beihang University, Beijing 100191, China
| | - Zhihao Zang
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, Beijing 100871, China
| | - Xingguo Wang
- School of Materials Science and Engineering, Beihang University, Beijing 100191, China
| | - Haifeng Que
- School of Materials Science and Engineering, Beihang University, Beijing 100191, China
| | - Lei Wang
- School of Materials Science and Engineering, Beihang University, Beijing 100191, China
| | - Kunpeng Si
- School of Materials Science and Engineering, Beihang University, Beijing 100191, China
| | - Peng Zhang
- School of Materials Science and Engineering, Beihang University, Beijing 100191, China
| | - Yu Ye
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, Beijing 100871, China
| | - Yongji Gong
- School of Materials Science and Engineering, Beihang University, Beijing 100191, China
- Key Laboratory of Intelligent Sensing Materials and Chip Integration Technology of Zhejiang Province, Hangzhou 310051, China
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21
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All-optical control of spin in a 2D van der Waals magnet. Nat Commun 2022; 13:5976. [PMID: 36216796 PMCID: PMC9551086 DOI: 10.1038/s41467-022-33343-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Accepted: 09/13/2022] [Indexed: 11/25/2022] Open
Abstract
Two-dimensional (2D) van der Waals magnets provide new opportunities for control of magnetism at the nanometre scale via mechanisms such as strain, voltage and the photovoltaic effect. Ultrafast laser pulses promise the fastest and most energy efficient means of manipulating electron spin and can be utilized for information storage. However, little is known about how laser pulses influence the spins in 2D magnets. Here we demonstrate laser-induced magnetic domain formation and all-optical switching in the recently discovered 2D van der Waals ferromagnet CrI3. While the magnetism of bare CrI3 layers can be manipulated with single laser pulses through thermal demagnetization processes, all-optical switching is achieved in nanostructures that combine ultrathin CrI3 with a monolayer of WSe2. The out-of-plane magnetization is switched with multiple femtosecond pulses of either circular or linear polarization, while single pulses result in less reproducible and partial switching. Our results imply that spin-dependent interfacial charge transfer between the WSe2 and CrI3 is the underpinning mechanism for the switching, paving the way towards ultrafast optical control of 2D van der Waals magnets for future photomagnetic recording and device technology. The use of light in driving the magnetization of materials has great technological potential, as well as allowing for insights into the fast dynamics of magnetic systems. Here, the authors combine CrI3, a van der Waals magnet, with WSe2, and demonstrate all optical switching of the resulting heterostructure.
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22
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Hussain B, Cottam MG. Dipole-exchange spin waves in two-dimensional van der Waals ferromagnetic films and stripes. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2022; 34:445801. [PMID: 35977537 DOI: 10.1088/1361-648x/ac8a82] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Accepted: 08/17/2022] [Indexed: 06/15/2023]
Abstract
A spin-wave (SW) theory that includes the long-range dipole-dipole interactions is presented for monolayers of van der Waals (vdW) ferromagnets for which the magnetic ions lie on a two-dimensional honeycomb lattice. The dipolar interactions provide an additional anisotropy in these materials, along with the Ising exchange interaction and/or single-ion anisotropies that typically stabilize the two-dimensional magnetic ordering. Analytical results for the linearized SW energies are obtained for the ferromagnets in two geometries: complete films and finite-width stripes (or ribbons). In both cases it is found that the inclusion of the dipole-dipole interactions leads to a shift and sometimes a splitting of the magnetic modes in the vdW structure. Also, in the latter case, where the edges are assumed to be along the zigzag lattice directions, the dipole-dipole interactions are found to play a role, as well as the exchange interactions, in modifying the localized edge SWs. Numerical examples are given, including applications to the ferromagnet CrI3.
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Affiliation(s)
- Bushra Hussain
- Department of Physics and Astronomy, University of Western Ontario, London, Ontario N6A 3K7, Canada
| | - Michael G Cottam
- Department of Physics and Astronomy, University of Western Ontario, London, Ontario N6A 3K7, Canada
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23
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Exciton-coupled coherent magnons in a 2D semiconductor. Nature 2022; 609:282-286. [PMID: 36071189 DOI: 10.1038/s41586-022-05024-1] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Accepted: 06/24/2022] [Indexed: 11/08/2022]
Abstract
The recent discoveries of two-dimensional (2D) magnets1-6 and their stacking into van der Waals structures7-11 have expanded the horizon of 2D phenomena. One exciting application is to exploit coherent magnons12 as energy-efficient information carriers in spintronics and magnonics13,14 or as interconnects in hybrid quantum systems15-17. A particular opportunity arises when a 2D magnet is also a semiconductor, as reported recently for CrSBr (refs. 18-20) and NiPS3 (refs. 21-23) that feature both tightly bound excitons with a large oscillator strength and potentially long-lived coherent magnons owing to the bandgap and spatial confinement. Although magnons and excitons are energetically mismatched by orders of magnitude, their coupling can lead to efficient optical access to spin information. Here we report strong magnon-exciton coupling in the 2D A-type antiferromagnetic semiconductor CrSBr. Coherent magnons launched by above-gap excitation modulate the exciton energies. Time-resolved exciton sensing reveals magnons that can coherently travel beyond seven micrometres, with a coherence time of above five nanoseconds. We observe these exciton-coupled coherent magnons in both even and odd numbers of layers, with and without compensated magnetization, down to the bilayer limit. Given the versatility of van der Waals heterostructures, these coherent 2D magnons may be a basis for optically accessible spintronics, magnonics and quantum interconnects.
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24
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Cham TMJ, Karimeddiny S, Dismukes AH, Roy X, Ralph DC, Luo YK. Anisotropic Gigahertz Antiferromagnetic Resonances of the Easy-Axis van der Waals Antiferromagnet CrSBr. NANO LETTERS 2022; 22:6716-6723. [PMID: 35925774 DOI: 10.1021/acs.nanolett.2c02124] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
We report measurements of antiferromagnetic resonances in the van der Waals easy-axis antiferromagnet CrSBr. The interlayer exchange field and magnetocrystalline anisotropy fields are comparable to laboratory magnetic fields, allowing a rich variety of gigahertz-frequency dynamical modes to be accessed. By mapping the resonance frequencies as a function of the magnitude and angle of applied magnetic field, we identify the different regimes of antiferromagnetic dynamics. The spectra show good agreement with a Landau-Lifshitz model for two antiferromagnetically coupled sublattices, accounting for interlayer exchange and triaxial magnetic anisotropy. Fits allow us to quantify the parameters governing the magnetic dynamics: At 5 K, the interlayer exchange field is μ0HE = 0.395(2) T, and the hard and intermediate-axis anisotropy parameters are μ0Hc = 1.30(2) T and μ0Ha = 0.383(7) T. The existence of within-plane anisotropy makes it possible to control the degree of hybridization between the antiferromagnetic resonances using an in-plane magnetic field.
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Affiliation(s)
| | | | - Avalon H Dismukes
- Department of Chemistry, Columbia University, New York, New York 10027, United States
| | - Xavier Roy
- Department of Chemistry, Columbia University, New York, New York 10027, United States
| | - Daniel C Ralph
- Cornell University, Ithaca, New York 14850, United States
- Kavli Institute at Cornell, Ithaca, New York 14853, United States
| | - Yunqiu Kelly Luo
- Cornell University, Ithaca, New York 14850, United States
- Kavli Institute at Cornell, Ithaca, New York 14853, United States
- Department of Physics and Astronomy, University of Southern California, Los Angeles, California 90089, United States
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25
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Coherent helicity-dependent spin-phonon oscillations in the ferromagnetic van der Waals crystal CrI 3. Nat Commun 2022; 13:4473. [PMID: 35918314 PMCID: PMC9345964 DOI: 10.1038/s41467-022-31786-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Accepted: 07/04/2022] [Indexed: 11/08/2022] Open
Abstract
The discovery of two-dimensional systems hosting intrinsic magnetic order represents a seminal addition to the rich landscape of van der Waals materials. CrI3 is an archetypal example, where the interdependence of structure and magnetism, along with strong light-matter interactions, provides a new platform to explore the optical control of magnetic and vibrational degrees of freedom at the nanoscale. However, the nature of magneto-structural coupling on its intrinsic ultrafast timescale remains a crucial open question. Here, we probe magnetic and vibrational dynamics in bulk CrI3 using ultrafast optical spectroscopy, revealing spin-flip scattering-driven demagnetization and strong transient exchange-mediated interactions between lattice vibrations and spin oscillations. The latter yields a coherent spin-coupled phonon mode that is highly sensitive to the driving pulse's helicity in the magnetically ordered phase. Our results elucidate the nature of ultrafast spin-lattice coupling in CrI3 and highlight its potential for applications requiring high-speed control of magnetism at the nanoscale.
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26
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Dong T, Zhang SJ, Wang NL. Recent Development of Ultrafast Optical Characterizations for Quantum Materials. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022:e2110068. [PMID: 35853841 DOI: 10.1002/adma.202110068] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 06/09/2022] [Indexed: 06/15/2023]
Abstract
The advent of intense ultrashort optical pulses spanning a frequency range from terahertz to the visible has opened a new era in the experimental investigation and manipulation of quantum materials. The generation of strong optical field in an ultrashort time scale enables the steering of quantum materials nonadiabatically, inducing novel phenomenon or creating new phases which may not have an equilibrium counterpart. Ultrafast time-resolved optical techniques have provided rich information and played an important role in characterization of the nonequilibrium and nonlinear properties of solid systems. Here, some of the recent progress of ultrafast optical techniques and their applications to the detection and manipulation of physical properties in selected quantum materials are reviewed. Specifically, the new development in the detection of the Higgs mode and photoinduced nonequilibrium response in the study of superconductors by time-resolved terahertz spectroscopy are discussed.
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Affiliation(s)
- Tao Dong
- International Center for Quantum Materials, School of Physics, Peking University, Beijing, 100871, China
| | - Si-Jie Zhang
- International Center for Quantum Materials, School of Physics, Peking University, Beijing, 100871, China
| | - Nan-Lin Wang
- International Center for Quantum Materials, School of Physics, Peking University, Beijing, 100871, China
- Collaborative Innovation Center of Quantum Matter, Beijing, 100871, China
- Beijing Academy of Quantum Information Sciences, Beijing, 100913, China
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27
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Wang QH, Bedoya-Pinto A, Blei M, Dismukes AH, Hamo A, Jenkins S, Koperski M, Liu Y, Sun QC, Telford EJ, Kim HH, Augustin M, Vool U, Yin JX, Li LH, Falin A, Dean CR, Casanova F, Evans RFL, Chshiev M, Mishchenko A, Petrovic C, He R, Zhao L, Tsen AW, Gerardot BD, Brotons-Gisbert M, Guguchia Z, Roy X, Tongay S, Wang Z, Hasan MZ, Wrachtrup J, Yacoby A, Fert A, Parkin S, Novoselov KS, Dai P, Balicas L, Santos EJG. The Magnetic Genome of Two-Dimensional van der Waals Materials. ACS NANO 2022; 16:6960-7079. [PMID: 35442017 PMCID: PMC9134533 DOI: 10.1021/acsnano.1c09150] [Citation(s) in RCA: 54] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Accepted: 02/23/2022] [Indexed: 05/23/2023]
Abstract
Magnetism in two-dimensional (2D) van der Waals (vdW) materials has recently emerged as one of the most promising areas in condensed matter research, with many exciting emerging properties and significant potential for applications ranging from topological magnonics to low-power spintronics, quantum computing, and optical communications. In the brief time after their discovery, 2D magnets have blossomed into a rich area for investigation, where fundamental concepts in magnetism are challenged by the behavior of spins that can develop at the single layer limit. However, much effort is still needed in multiple fronts before 2D magnets can be routinely used for practical implementations. In this comprehensive review, prominent authors with expertise in complementary fields of 2D magnetism (i.e., synthesis, device engineering, magneto-optics, imaging, transport, mechanics, spin excitations, and theory and simulations) have joined together to provide a genome of current knowledge and a guideline for future developments in 2D magnetic materials research.
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Affiliation(s)
- Qing Hua Wang
- Materials
Science and Engineering, School for Engineering of Matter, Transport
and Energy, Arizona State University, Tempe, Arizona 85287, United States
| | - Amilcar Bedoya-Pinto
- NISE
Department, Max Planck Institute of Microstructure
Physics, 06120 Halle, Germany
- Instituto
de Ciencia Molecular (ICMol), Universitat
de València, 46980 Paterna, Spain
| | - Mark Blei
- Materials
Science and Engineering, School for Engineering of Matter, Transport
and Energy, Arizona State University, Tempe, Arizona 85287, United States
| | - Avalon H. Dismukes
- Department
of Chemistry, Columbia University, New York, New York 10027, United States
| | - Assaf Hamo
- Department
of Physics, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Sarah Jenkins
- Twist
Group,
Faculty of Physics, University of Duisburg-Essen, Campus Duisburg, 47057 Duisburg, Germany
| | - Maciej Koperski
- Institute
for Functional Intelligent Materials, National
University of Singapore, 117544 Singapore
| | - Yu Liu
- Condensed
Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - Qi-Chao Sun
- Physikalisches
Institut, University of Stuttgart, 70569 Stuttgart, Germany
| | - Evan J. Telford
- Department
of Chemistry, Columbia University, New York, New York 10027, United States
- Department
of Physics, Columbia University, New York, New York 10027, United States
| | - Hyun Ho Kim
- School
of Materials Science and Engineering, Department of Energy Engineering
Convergence, Kumoh National Institute of
Technology, Gumi 39177, Korea
| | - Mathias Augustin
- Institute
for Condensed Matter Physics and Complex Systems, School of Physics
and Astronomy, The University of Edinburgh, Edinburgh, EH9 3FD, United Kingdom
- Donostia
International Physics Center (DIPC), 20018 Donostia-San Sebastián, Basque Country, Spain
| | - Uri Vool
- Department
of Physics, Harvard University, Cambridge, Massachusetts 02138, United States
- John Harvard
Distinguished Science Fellows Program, Harvard
University, Cambridge, Massachusetts 02138, United States
| | - Jia-Xin Yin
- Laboratory
for Topological Quantum Matter and Spectroscopy, Department of Physics, Princeton University, Princeton, New Jersey 08544, United States
| | - Lu Hua Li
- Institute
for Frontier Materials, Deakin University, Geelong Waurn Ponds Campus, Waurn Ponds, Victoria 3216, Australia
| | - Alexey Falin
- Institute
for Frontier Materials, Deakin University, Geelong Waurn Ponds Campus, Waurn Ponds, Victoria 3216, Australia
| | - Cory R. Dean
- Department
of Physics, Columbia University, New York, New York 10027, United States
| | - Fèlix Casanova
- CIC nanoGUNE
BRTA, 20018 Donostia - San Sebastián, Basque
Country, Spain
- IKERBASQUE,
Basque Foundation for Science, 48013 Bilbao, Basque Country, Spain
| | - Richard F. L. Evans
- Department
of Physics, University of York, Heslington, York YO10 5DD, United Kingdom
| | - Mairbek Chshiev
- Université
Grenoble Alpes, CEA, CNRS, Spintec, 38000 Grenoble, France
- Institut
Universitaire de France, 75231 Paris, France
| | - Artem Mishchenko
- Department
of Physics and Astronomy, University of
Manchester, Manchester, M13 9PL, United Kingdom
- National
Graphene Institute, University of Manchester, Manchester, M13 9PL, United Kingdom
| | - Cedomir Petrovic
- Condensed
Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - Rui He
- Department
of Electrical and Computer Engineering, Texas Tech University, 910 Boston Avenue, Lubbock, Texas 79409, United
States
| | - Liuyan Zhao
- Department
of Physics, University of Michigan, 450 Church Street, Ann Arbor, Michigan 48109, United States
| | - Adam W. Tsen
- Institute
for Quantum Computing and Department of Chemistry, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| | - Brian D. Gerardot
- SUPA, Institute
of Photonics and Quantum Sciences, Heriot-Watt
University, Edinburgh EH14 4AS, United Kingdom
| | - Mauro Brotons-Gisbert
- SUPA, Institute
of Photonics and Quantum Sciences, Heriot-Watt
University, Edinburgh EH14 4AS, United Kingdom
| | - Zurab Guguchia
- Laboratory
for Muon Spin Spectroscopy, Paul Scherrer
Institute, CH-5232 Villigen PSI, Switzerland
| | - Xavier Roy
- Department
of Chemistry, Columbia University, New York, New York 10027, United States
| | - Sefaattin Tongay
- Materials
Science and Engineering, School for Engineering of Matter, Transport
and Energy, Arizona State University, Tempe, Arizona 85287, United States
| | - Ziwei Wang
- Department
of Physics and Astronomy, University of
Manchester, Manchester, M13 9PL, United Kingdom
- National
Graphene Institute, University of Manchester, Manchester, M13 9PL, United Kingdom
| | - M. Zahid Hasan
- Materials
Sciences Division, Lawrence Berkeley National
Laboratory, Berkeley, California 94720, United States
- Princeton
Institute for Science and Technology of Materials, Princeton University, Princeton, New Jersey 08544, United States
- National
High Magnetic Field Laboratory, Florida
State University, Tallahassee, Florida 32310, United States
| | - Joerg Wrachtrup
- Physikalisches
Institut, University of Stuttgart, 70569 Stuttgart, Germany
- Max Planck
Institute for Solid State Research, 70569 Stuttgart, Germany
| | - Amir Yacoby
- Department
of Physics, Harvard University, Cambridge, Massachusetts 02138, United States
- John A.
Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Albert Fert
- Donostia
International Physics Center (DIPC), 20018 Donostia-San Sebastián, Basque Country, Spain
- Unité
Mixte de Physique, CNRS, Thales, Université Paris-Saclay, 91767 Palaiseau, France
- Department
of Materials Physics UPV/EHU, 20018 Donostia - San Sebastián, Basque Country, Spain
| | - Stuart Parkin
- NISE
Department, Max Planck Institute of Microstructure
Physics, 06120 Halle, Germany
| | - Kostya S. Novoselov
- Institute
for Functional Intelligent Materials, National
University of Singapore, 117544 Singapore
| | - Pengcheng Dai
- Department
of Physics and Astronomy, Rice University, Houston, Texas 77005, United States
| | - Luis Balicas
- National
High Magnetic Field Laboratory, Florida
State University, Tallahassee, Florida 32310, United States
- Department
of Physics, Florida State University, Tallahassee, Florida 32306, United States
| | - Elton J. G. Santos
- Institute
for Condensed Matter Physics and Complex Systems, School of Physics
and Astronomy, The University of Edinburgh, Edinburgh, EH9 3FD, United Kingdom
- Donostia
International Physics Center (DIPC), 20018 Donostia-San Sebastián, Basque Country, Spain
- Higgs Centre
for Theoretical Physics, The University
of Edinburgh, Edinburgh EH9 3FD, United Kingdom
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28
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Huey WLB, Ochs AM, Williams AJ, Zhang Y, Kraguljac S, Deng Z, Moore CE, Windl W, Lau CN, Goldberger JE. Cr xPt 1-xTe 2 ( x ≤ 0.45): A Family of Air-Stable and Exfoliatable van der Waals Ferromagnets. ACS NANO 2022; 16:3852-3860. [PMID: 35176210 DOI: 10.1021/acsnano.1c08681] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The development of thermally robust, air-stable, exfoliatable two-dimensional van der Waals ferromagnetic materials with high transition temperatures is of great importance. Here, we establish a family of magnetic alloys, CrxPt1-xTe2 (x ≤ 0.45), that combines the stability of the late transition metal dichalcogenide PtTe2 with magnetism from Cr. These materials are easily grown in crystal form from the melt, are stable in ambient conditions, and have among the highest concentrations of magnetic element substitution in transition metal dichalcogenide alloys. The highest Cr-substituted material, Cr0.45Pt0.55Te2, exhibits ferromagnetic behavior below 220 K, and the easy axis is along the c-axis of the material, as determined using a combination of neutron diffraction and magnetic susceptibility measurements. These materials are metallic, with appreciable magnetoresistance below the Curie temperature. Single-crystal and powder diffraction measurements indicate Cr readily alloys onto the Pt site and does not sit in the van der Waals space, allowing these materials to be readily exfoliated to the few-layer regime. In summary, this air-stable, exfoliatable, high transition temperature ferromagnet shows great potential as building block for future 2D devices.
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Affiliation(s)
- Warren L B Huey
- Department of Chemistry and Biochemistry, The Ohio State University, 100 W. 18th Avenue, Columbus, Ohio 43210, United States
| | - Andrew M Ochs
- Department of Chemistry and Biochemistry, The Ohio State University, 100 W. 18th Avenue, Columbus, Ohio 43210, United States
| | - Archibald J Williams
- Department of Chemistry and Biochemistry, The Ohio State University, 100 W. 18th Avenue, Columbus, Ohio 43210, United States
| | - Yuxin Zhang
- Department of Physics, The Ohio State University, 191 W. Woodruff Avenue, Columbus, Ohio 43210, United States
| | - Simo Kraguljac
- Department of Chemistry and Biochemistry, The Ohio State University, 100 W. 18th Avenue, Columbus, Ohio 43210, United States
| | - Ziling Deng
- Department of Materials Science and Engineering, The Ohio State University, Columbus, Ohio 43210, United States
| | - Curtis E Moore
- Department of Chemistry and Biochemistry, The Ohio State University, 100 W. 18th Avenue, Columbus, Ohio 43210, United States
| | - Wolfgang Windl
- Department of Materials Science and Engineering, The Ohio State University, Columbus, Ohio 43210, United States
| | - Chun Ning Lau
- Department of Physics, The Ohio State University, 191 W. Woodruff Avenue, Columbus, Ohio 43210, United States
| | - Joshua E Goldberger
- Department of Chemistry and Biochemistry, The Ohio State University, 100 W. 18th Avenue, Columbus, Ohio 43210, United States
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29
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Peng B, Chen Z, Li Y, Liu Z, Liang D, Deng L. Multiwavelength magnetic coding of helical luminescence in ferromagnetic 2D layered CrI 3. iScience 2022; 25:103623. [PMID: 35005559 PMCID: PMC8718829 DOI: 10.1016/j.isci.2021.103623] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 11/15/2021] [Accepted: 12/10/2021] [Indexed: 11/01/2022] Open
Abstract
Two-dimensional (2D) van der Waals (vdW) ferromagnets have opened new avenues for manipulating spin at the limits of single or few atomic layers, and for creating unique magneto-exciton devices through the coupling of ferromagnetic (FM) orders and excitons. However, 2D vdW ferromagnets explored so far have rarely possessed exciton behaviors; to date, FM CrI3 have been revealed to show ligand-field photoluminescence correlated with FM ordering, but typically with a broad emission peak. Here, we report a straightforward approach to realize strong coupling of narrow helical emission and FM orders in CrI3 through microsphere cavity. The resonant whispering-gallery modes (WGM) of SiO2 microspheres cause strong oscillation helical emissions with a full width at half-maximum (FWHM) of ∼5 nm under continuous wave excitation. Reversible magnetic coding of helical luminescence is realized in the range of 950-1100 nm. This work enables numerous opportunities for creating magnetic encoding lasing for photonic integrated chips.
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Affiliation(s)
- Bo Peng
- National Engineering Research Center of Electromagnetic Radiation Control Materials, School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu 611731, China.,State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 611731, China
| | - Zhiyong Chen
- National Engineering Research Center of Electromagnetic Radiation Control Materials, School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu 611731, China.,State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 611731, China
| | - Yue Li
- National Engineering Research Center of Electromagnetic Radiation Control Materials, School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu 611731, China.,State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 611731, China
| | - Zhen Liu
- National Engineering Research Center of Electromagnetic Radiation Control Materials, School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu 611731, China.,State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 611731, China
| | - Difei Liang
- National Engineering Research Center of Electromagnetic Radiation Control Materials, School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu 611731, China.,State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 611731, China
| | - Longjiang Deng
- National Engineering Research Center of Electromagnetic Radiation Control Materials, School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu 611731, China.,State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 611731, China
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30
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Xue F, Haney PM. Intrinsic staggered spin-orbit torque for the electrical control of antiferromagnets - application to CrI 3. PHYSICAL REVIEW. B 2021; 104:10.1103/PhysRevB.104.224414. [PMID: 36589897 PMCID: PMC9805323 DOI: 10.1103/physrevb.104.224414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Spin-orbit torque enables the electrical control of the orientation of ferromagnets' or antiferromagnets' order parameter. In this work we consider antiferromagnets in which the magnetic sublattices are connected by inversion+time reversal symmetry, and in which the exchange and anisotropy energies are similar in magnitude. We identify the staggered dampinglike spin-orbit torque as the key mechanism for electrical excitation of the Néel vector for this case. To illustrate this scenario, we examine the 2-d Van der Waals antiferromagnetic bilayer CrI3, in the n-doped regime. Using a combination of first-principles calculations of the spin-orbit torque and an analysis of the ensuing spin dynamics, we show that the deterministic electrical switching of the Néel vector is the result of dampinglike spin-orbit torque which is staggered on the magnetic sublattices.
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Affiliation(s)
- Fei Xue
- Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
- Institute for Research in Electronics and Applied Physics & Maryland Nanocenter, University of Maryland, College Park, MD 20742, USA
- Department of Physics, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Paul M Haney
- Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
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31
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Abstract
Van der Waals magnets have emerged as a fertile ground for the exploration of highly tunable spin physics and spin-related technology. Two-dimensional (2D) magnons in van der Waals magnets are collective excitation of spins under strong confinement. Although considerable progress has been made in understanding 2D magnons, a crucial magnon device called the van der Waals magnon valve, in which the magnon signal can be completely and repeatedly turned on and off electrically, has yet to be realized. Here we demonstrate such magnon valves based on van der Waals antiferromagnetic insulator MnPS3. By applying DC electric current through the gate electrode, we show that the second harmonic thermal magnon (SHM) signal can be tuned from positive to negative. The guaranteed zero crossing during this tuning demonstrates a complete blocking of SHM transmission, arising from the nonlinear gate dependence of the non-equilibrium magnon density in the 2D spin channel. Using the switchable magnon valves we demonstrate a magnon-based inverter. These results illustrate the potential of van der Waals anti-ferromagnets for studying highly tunable spin-wave physics and for application in magnon-base circuitry in future information technology. A major challenge in magnon based approaches to information processing lies in developing valves to allow or supress the magnon signal. Here, Chen et al demonstrate a van der Waals magnet based magnon valve which can be tuned electrically over an exceptionally wide range.
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32
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Olsen T. Unified Treatment of Magnons and Excitons in Monolayer CrI_{3} from Many-Body Perturbation Theory. PHYSICAL REVIEW LETTERS 2021; 127:166402. [PMID: 34723581 DOI: 10.1103/physrevlett.127.166402] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Accepted: 09/22/2021] [Indexed: 06/13/2023]
Abstract
We present first principles calculations of the two-particle excitation spectrum of CrI_{3} using many-body perturbation theory including spin-orbit coupling. Specifically, we solve the Bethe-Salpeter equation, which is equivalent to summing up all ladder diagrams with static screening, and it is shown that excitons as well as magnons can be extracted seamlessly from the calculations. The resulting optical absorption spectrum as well as the magnon dispersion agree very well with recent measurements, and we extract the amplitude for optical excitation of magnons resulting from spin-orbit interactions. Importantly, the results do not rely on any assumptions of the microscopic magnetic interactions such as Dzyaloshinskii-Moriya (DM), Kitaev, or biquadratic interactions, and we obtain a model independent estimate of the gap between acoustic and optical magnons of 0.3 meV. In addition, we resolve the magnon wave function in terms of band transitions and show that the magnon carries a spin that is significantly smaller than ℏ. This highlights the importance of terms that do not commute with S^{z} in any Heisenberg model description.
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Affiliation(s)
- Thomas Olsen
- CAMD, Department of Physics, Technical University of Denmark, 2800 Kgs. Lyngby Denmark
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33
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Zhang XX, Jiang S, Lee J, Lee C, Mak KF, Shan J. Spin Dynamics Slowdown near the Antiferromagnetic Critical Point in Atomically Thin FePS 3. NANO LETTERS 2021; 21:5045-5052. [PMID: 34106709 DOI: 10.1021/acs.nanolett.1c00870] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Two-dimensional (2D) magnetic materials have attracted much recent interest with unique properties emerging at the few-layer limit. Beyond the reported impacts on the static magnetic properties, the effects of reducing the dimensionality on the magnetization dynamics are also of fundamental interest and importance for 2D device development. In this report, we investigate the spin dynamics in atomically thin antiferromagnetic FePS3 of varying layer numbers using ultrafast pump-probe spectroscopy. Following the absorption of an optical pump pulse, the time evolution of the antiferromagnetic order parameter is probed by magnetic linear birefringence. We observe a strong divergence in the demagnetization time near the Néel temperature. The divergence can be characterized by a power-law dependence on the reduced temperature, with an exponent decreasing with sample thickness. We compare our results to expectations from critical slowing down and a two-temperature model involving spins and phonons and discuss the possible relevance of spin-substrate phonon interactions.
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Affiliation(s)
- Xiao-Xiao Zhang
- Department of Physics, University of Florida, Gainesville, Florida 32611, United States
- Kavli Institute at Cornell for Nanoscale Science, Ithaca, New York 14850, United States
| | - Shengwei Jiang
- Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, New York 14850, United States
- School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Jinhwan Lee
- Mechanical Engineering, Sungkyunkwan University, 2066 Seoburo Jangan-gu, Suwon, Gyeonggi-do 16419, Korea
| | - Changgu Lee
- Mechanical Engineering, Sungkyunkwan University, 2066 Seoburo Jangan-gu, Suwon, Gyeonggi-do 16419, Korea
| | - Kin Fai Mak
- Kavli Institute at Cornell for Nanoscale Science, Ithaca, New York 14850, United States
- Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, New York 14850, United States
- School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14850, United States
| | - Jie Shan
- Kavli Institute at Cornell for Nanoscale Science, Ithaca, New York 14850, United States
- Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, New York 14850, United States
- School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14850, United States
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34
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Afanasiev D, Hortensius JR, Matthiesen M, Mañas-Valero S, Šiškins M, Lee M, Lesne E, van der Zant HSJ, Steeneken PG, Ivanov BA, Coronado E, Caviglia AD. Controlling the anisotropy of a van der Waals antiferromagnet with light. SCIENCE ADVANCES 2021; 7:eabf3096. [PMID: 34078601 PMCID: PMC8172129 DOI: 10.1126/sciadv.abf3096] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2020] [Accepted: 04/16/2021] [Indexed: 05/26/2023]
Abstract
Van der Waals magnets provide an ideal playground to explore the fundamentals of low-dimensional magnetism and open opportunities for ultrathin spin-processing devices. The Mermin-Wagner theorem dictates that as in reduced dimensions isotropic spin interactions cannot retain long-range correlations, the long-range spin order is stabilized by magnetic anisotropy. Here, using ultrashort pulses of light, we control magnetic anisotropy in the two-dimensional van der Waals antiferromagnet NiPS3 Tuning the photon energy in resonance with an orbital transition between crystal field split levels of the nickel ions, we demonstrate the selective activation of a subterahertz magnon mode with markedly two-dimensional behavior. The pump polarization control of the magnon amplitude confirms that the activation is governed by the photoinduced magnetic anisotropy axis emerging in response to photoexcitation of ground state electrons to states with a lower orbital symmetry. Our results establish pumping of orbital resonances as a promising route for manipulating magnetic order in low-dimensional (anti)ferromagnets.
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Affiliation(s)
- Dmytro Afanasiev
- Kavli Institute of Nanoscience, Delft University of Technology, P.O. Box 5046, 2600 GA Delft, Netherlands.
- Department of Physics, University of Regensburg, Regensburg, Germany
| | - Jorrit R Hortensius
- Kavli Institute of Nanoscience, Delft University of Technology, P.O. Box 5046, 2600 GA Delft, Netherlands
| | - Mattias Matthiesen
- 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
| | - Makars Šiškins
- Kavli Institute of Nanoscience, Delft University of Technology, P.O. Box 5046, 2600 GA Delft, Netherlands
| | - Martin Lee
- Kavli Institute of Nanoscience, Delft University of Technology, P.O. Box 5046, 2600 GA Delft, Netherlands
| | - Edouard Lesne
- Kavli Institute of Nanoscience, Delft University of Technology, P.O. Box 5046, 2600 GA Delft, Netherlands
| | - Herre S J van der Zant
- Kavli Institute of Nanoscience, Delft University of Technology, P.O. Box 5046, 2600 GA Delft, Netherlands
| | - Peter G Steeneken
- Kavli Institute of Nanoscience, Delft University of Technology, P.O. Box 5046, 2600 GA Delft, Netherlands
| | - Boris A Ivanov
- Institute of Magnetism, National Academy of Sciences and Ministry of Education and Science, 03142 Kyiv, Ukraine
| | - Eugenio Coronado
- Instituto de Ciencia Molecular (ICMol), Universitat de Valencia Catedrático José Beltrán 2, 46980 Paterna, Spain
| | - Andrea D Caviglia
- Kavli Institute of Nanoscience, Delft University of Technology, P.O. Box 5046, 2600 GA Delft, Netherlands
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35
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Sun QC, Song T, Anderson E, Brunner A, Förster J, Shalomayeva T, Taniguchi T, Watanabe K, Gräfe J, Stöhr R, Xu X, Wrachtrup J. Magnetic domains and domain wall pinning in atomically thin CrBr 3 revealed by nanoscale imaging. Nat Commun 2021; 12:1989. [PMID: 33790290 PMCID: PMC8012586 DOI: 10.1038/s41467-021-22239-4] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Accepted: 03/03/2021] [Indexed: 11/09/2022] Open
Abstract
The emergence of atomically thin van der Waals magnets provides a new platform for the studies of two-dimensional magnetism and its applications. However, the widely used measurement methods in recent studies cannot provide quantitative information of the magnetization nor achieve nanoscale spatial resolution. These capabilities are essential to explore the rich properties of magnetic domains and spin textures. Here, we employ cryogenic scanning magnetometry using a single-electron spin of a nitrogen-vacancy center in a diamond probe to unambiguously prove the existence of magnetic domains and study their dynamics in atomically thin CrBr3. By controlling the magnetic domain evolution as a function of magnetic field, we find that the pinning effect is a dominant coercivity mechanism and determine the magnetization of a CrBr3 bilayer to be about 26 Bohr magnetons per square nanometer. The high spatial resolution of this technique enables imaging of magnetic domains and allows to locate the sites of defects that pin the domain walls and nucleate the reverse domains. Our work highlights scanning nitrogen-vacancy center magnetometry as a quantitative probe to explore nanoscale features in two-dimensional magnets. Van der Waals (vdW) magnets have allowed researchers to explore the two dimensional limit of magnetisation; however experimental challenges have hindered analysis of magnetic domains. Here, using an NV centre based probe, the authors analyse the nature of magnetic domains in the vdW magnet, CrBr3.
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Affiliation(s)
- Qi-Chao Sun
- 3. Physikalisches Institut, University of Stuttgart, Stuttgart, Germany.
| | - Tiancheng Song
- Department of Physics, University of Washington, Seattle, WA, USA
| | - Eric Anderson
- Department of Physics, University of Washington, Seattle, WA, USA
| | - Andreas Brunner
- 3. Physikalisches Institut, University of Stuttgart, Stuttgart, Germany
| | - Johannes Förster
- Max Planck Institute for Intelligent Systems, Stuttgart, Germany
| | | | | | - Kenji Watanabe
- National Institute for Materials Science, Tsukuba, Ibaraki, Japan
| | - Joachim Gräfe
- Max Planck Institute for Intelligent Systems, Stuttgart, Germany
| | - Rainer Stöhr
- 3. Physikalisches Institut, University of Stuttgart, Stuttgart, Germany. .,Center for Applied Quantum Technology, University of Stuttgart, Stuttgart, Germany.
| | - Xiaodong Xu
- Department of Physics, University of Washington, Seattle, WA, USA.,Department of Materials Science and Engineering, University of Washington, Seattle, WA, USA
| | - Jörg Wrachtrup
- 3. Physikalisches Institut, University of Stuttgart, Stuttgart, Germany.,Max Planck Institute for Solid State Research, Stuttgart, Germany
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36
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Zhang S, Xu R, Luo N, Zou X. Two-dimensional magnetic materials: structures, properties and external controls. NANOSCALE 2021; 13:1398-1424. [PMID: 33416064 DOI: 10.1039/d0nr06813f] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Since the discovery of intrinsic ferromagnetism in atomically thin Cr2Gr2Te6 and CrI3 in 2017, research on two-dimensional (2D) magnetic materials has become a highlighted topic. Based on 2D magnetic materials and their heterostructures, exotic physical phenomena at the atomically thin limit have been discovered, such as the quantum anomalous Hall effect, magneto-electric multiferroics, and magnon valleytronics. Furthermore, magnetism in these ultrathin magnets can be effectively controlled by external perturbations, such as electric field, strain, doping, chemical functionalization, and stacking engineering. These attributes make 2D magnets ideal platforms for fundamental research and promising candidates for various spintronic applications. This review aims at providing an overview of the structures, properties, and external controls of 2D magnets, as well as the challenges and potential opportunities in this field.
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Affiliation(s)
- Shuqing Zhang
- Shenzhen Geim Graphene Center (SGC), Tsinghua-Berkeley Shenzhen Institute (TBSI) & Tsinghua Shenzhen International Graduate School (TSIGS), Tsinghua University, Shenzhen 518055, China.
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37
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Kapoor LN, Mandal S, Adak PC, Patankar M, Manni S, Thamizhavel A, Deshmukh MM. Observation of Standing Spin Waves in a van der Waals Magnetic Material. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2005105. [PMID: 33244778 DOI: 10.1002/adma.202005105] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 10/04/2020] [Indexed: 06/11/2023]
Abstract
Spin waves are studied for data storage, communication, and logic circuits in the field of spintronics based on their potential to substitute electrons. The recent discovery of magnetism in 2D systems such as monolayer CrI3 and Cr2 Ge2 Te6 has led to a renewed interest in such applications of magnetism in the 2D limit. Here, direct evidence of standing spin waves is presented along with the uniform precessional resonance modes in the van der Waals magnetic material, CrCl3 . This is the first direct observation of standing spin-wave modes, set up along a thickness of 20 mm, in a van der Waals material. Standing spin waves are detected in the vicinity of both branches, optical and acoustic, of the antiferromagnetic resonance. Magnon-magnon coupling and softening of resonance modes with temperature enable extraction of interlayer exchange field as a function of temperature.
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Affiliation(s)
- Lucky N Kapoor
- Department of Condensed Matter Physics and Materials Science, Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai, 400005, India
| | - Supriya Mandal
- Department of Condensed Matter Physics and Materials Science, Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai, 400005, India
| | - Pratap Chandra Adak
- Department of Condensed Matter Physics and Materials Science, Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai, 400005, India
| | - Meghan Patankar
- Department of Condensed Matter Physics and Materials Science, Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai, 400005, India
| | - Soham Manni
- Department of Condensed Matter Physics and Materials Science, Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai, 400005, India
- Department of Physics, Indian Institute of Technology Palakkad, Palakkad, 678557, India
| | - Arumugam Thamizhavel
- Department of Condensed Matter Physics and Materials Science, Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai, 400005, India
| | - Mandar M Deshmukh
- Department of Condensed Matter Physics and Materials Science, Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai, 400005, India
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38
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Twist-angle dependence of moiré excitons in WS 2/MoSe 2 heterobilayers. Nat Commun 2020; 11:5888. [PMID: 33208738 PMCID: PMC7675978 DOI: 10.1038/s41467-020-19466-6] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 10/14/2020] [Indexed: 02/05/2023] Open
Abstract
Moiré lattices formed in twisted van der Waals bilayers provide a unique, tunable platform to realize coupled electron or exciton lattices unavailable before. While twist angle between the bilayer has been shown to be a critical parameter in engineering the moiré potential and enabling novel phenomena in electronic moiré systems, a systematic experimental study as a function of twist angle is still missing. Here we show that not only are moiré excitons robust in bilayers of even large twist angles, but also properties of the moiré excitons are dependant on, and controllable by, the moiré reciprocal lattice period via twist-angle tuning. From the twist-angle dependence, we furthermore obtain the effective mass of the interlayer excitons and the electron inter-layer tunneling strength, which are difficult to measure experimentally otherwise. These findings pave the way for understanding and engineering rich moiré-lattice induced phenomena in angle-twisted semiconductor van der Waals heterostructures.
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39
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Soriano D, Katsnelson MI, Fernández-Rossier J. Magnetic Two-Dimensional Chromium Trihalides: A Theoretical Perspective. NANO LETTERS 2020; 20:6225-6234. [PMID: 32787171 DOI: 10.1021/acs.nanolett.0c02381] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The discovery of ferromagnetic order in monolayer two-dimensional (2D) crystals has opened a new venue in the field of 2D materials. Two-dimensional magnets are not only interesting on their own, but their integration in van der Waals heterostructures allows for the observation of new and exotic effects in the ultrathin limit. The family of chromium trihalides, CrI3, CrBr3, and CrCl3, is so far the most studied among magnetic 2D crystals. In this Mini Review, we provide a perspective of the state of the art of the theoretical understanding of magnetic 2D trihalides, most of which will also be relevant for other 2D magnets, such as vanadium trihalides. We discuss both the well-established facts, such as the origin of the magnetic moment and magnetic anisotropy, and address as well open issues such as the nature of the anisotropic spin couplings and the magnitude of the magnon gap. Recent theoretical predictions on Moiré magnets and magnetic skyrmions are also discussed. Finally, we give some prospects about the future interest of these materials and possible device applications.
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Affiliation(s)
- D Soriano
- Institute for Molecules and Materials, Radboud University, NL-6525 AJ Nijmegen, The Netherlands
| | - M I Katsnelson
- Institute for Molecules and Materials, Radboud University, NL-6525 AJ Nijmegen, The Netherlands
| | - J Fernández-Rossier
- QuantaLab, International Iberian Nanotechnology Laboratory (INL), Avenido Mestre José Veiga, 4715-330 Braga, Portugal
- Departamento de Física Aplicada, Universidad de Alicante, 03690, Alicante, Spain
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