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De Vita A, Sant R, Polewczyk V, van der Laan G, Brookes NB, Kong T, Cava RJ, Rossi G, Vinai G, Panaccione G. Evidence of Temperature-Dependent Interplay between Spin and Orbital Moment in van der Waals Ferromagnet VI 3. NANO LETTERS 2024; 24:1487-1493. [PMID: 38285518 DOI: 10.1021/acs.nanolett.3c03525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2024]
Abstract
van der Waals materials provide a versatile toolbox for the emergence of new quantum phenomena and fabrication of functional heterostructures. Among them, the trihalide VI3 stands out for its unique magnetic and structural landscape. Here we investigate the spin and orbital magnetic degrees of freedom in the layered ferromagnet VI3 by means of temperature-dependent X-ray absorption spectroscopy and X-ray magnetic circular and linear dichroism. We detect localized electronic states and reduced magnetic dimensionality, due to electronic correlations. We furthermore provide experimental evidence of (a) an unquenched orbital magnetic moment (up to 0.66(7) μB/V atom) in the ferromagnetic state and (b) an instability of the orbital moment in the proximity of the spin reorientation transition. Our results support a coherent picture where electronic correlations give rise to a strong magnetic anisotropy and a large orbital moment and establish VI3 as a prime candidate for the study of orbital quantum effects.
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Affiliation(s)
- Alessandro De Vita
- Dipartimento di Fisica, Universitá degli Studi di Milano, Via Celoria 16, I-20133 Milano, Italy
- Istituto Officina dei Materiali (IOM)-CNR, Laboratorio TASC, in Area Science Park, S.S.14, km 163.5, I-34149 Trieste, Italy
| | - Roberto Sant
- ESRF, The European Synchrotron, 71 Avenue des Martyrs, CS40220, 38043 Grenoble Cedex 9, France
| | - Vincent Polewczyk
- Istituto Officina dei Materiali (IOM)-CNR, Laboratorio TASC, in Area Science Park, S.S.14, km 163.5, I-34149 Trieste, Italy
| | - Gerrit van der Laan
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, U.K
| | - Nicholas B Brookes
- ESRF, The European Synchrotron, 71 Avenue des Martyrs, CS40220, 38043 Grenoble Cedex 9, France
| | - Tai Kong
- Department of Chemistry, Princeton University, Princeton, New Jersey 08540, United States
| | - Robert J Cava
- Department of Chemistry, Princeton University, Princeton, New Jersey 08540, United States
| | - Giorgio Rossi
- Dipartimento di Fisica, Universitá degli Studi di Milano, Via Celoria 16, I-20133 Milano, Italy
- Istituto Officina dei Materiali (IOM)-CNR, Laboratorio TASC, in Area Science Park, S.S.14, km 163.5, I-34149 Trieste, Italy
| | - Giovanni Vinai
- Istituto Officina dei Materiali (IOM)-CNR, Laboratorio TASC, in Area Science Park, S.S.14, km 163.5, I-34149 Trieste, Italy
| | - Giancarlo Panaccione
- Istituto Officina dei Materiali (IOM)-CNR, Laboratorio TASC, in Area Science Park, S.S.14, km 163.5, I-34149 Trieste, Italy
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2
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Liu D, Oppliger J, Cahlík A, Witteveen C, von Rohr FO, Natterer FD. A sacrificial magnet concept for field dependent surface science studies. MethodsX 2022; 10:101964. [PMID: 36578290 PMCID: PMC9791577 DOI: 10.1016/j.mex.2022.101964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Accepted: 12/05/2022] [Indexed: 12/13/2022] Open
Abstract
We demonstrate a straightforward approach to integrating a magnetic field into a low-temperature scanning tunneling microscope (STM) by adhering an NdFeB permanent magnet to a magnetizable sample plate. To render our magnet concept compatible with high-temperature sample cleaning procedures, we make the irreversible demagnetization of the magnet a central part of our preparation cycle. After sacrificing the magnet by heating it above its Curie temperature, we use a transfer tool to attach a new magnet in-situ prior to transferring the sample into the STM. We characterize the magnetic field created by the magnet using the Abrikosov vortex lattice of superconducting NbSe2. Excellent agreement between the distance dependent magnetic fields from experiments and simulations allows us to predict the magnitude and orientation of magnetic flux at any location with respect to the magnet and the sample plate. Our concept is an accessible solution for field-dependent surface science studies that require fields in the range of up to 400 mT and otherwise detrimental heating procedures.•Accessible magnetic field generation.•Selectable field strength and orientation.•Compatible with high-temperature sample preparation.
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Affiliation(s)
- Danyang Liu
- Department of Physics, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland
| | - Jens Oppliger
- Department of Physics, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland
| | - Aleš Cahlík
- Department of Physics, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland
| | - Catherine Witteveen
- Department of Physics, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, CH-1211 Geneva, Switzerland
| | - Fabian O. von Rohr
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, CH-1211 Geneva, Switzerland
| | - Fabian Donat Natterer
- Department of Physics, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland
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3
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Jin D, Xia Y, Christensen T, Freeman M, Wang S, Fong KY, Gardner GC, Fallahi S, Hu Q, Wang Y, Engel L, Xiao ZL, Manfra MJ, Fang NX, Zhang X. Topological kink plasmons on magnetic-domain boundaries. Nat Commun 2019; 10:4565. [PMID: 31594922 PMCID: PMC6783483 DOI: 10.1038/s41467-019-12092-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Accepted: 07/31/2019] [Indexed: 11/09/2022] Open
Abstract
Two-dimensional topological materials bearing time reversal-breaking magnetic fields support protected one-way edge modes. Normally, these edge modes adhere to physical edges where material properties change abruptly. However, even in homogeneous materials, topology still permits a unique form of edge modes – kink modes – residing at the domain boundaries of magnetic fields within the materials. This scenario, despite being predicted in theory, has rarely been demonstrated experimentally. Here, we report our observation of topologically-protected high-frequency kink modes – kink magnetoplasmons (KMPs) – in a GaAs/AlGaAs two-dimensional electron gas (2DEG) system. These KMPs arise at a domain boundary projected from an externally-patterned magnetic field onto a uniform 2DEG. They propagate unidirectionally along the boundary, protected by a difference of gap Chern numbers (\documentclass[12pt]{minimal}
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\begin{document}$$\pm1$$\end{document}±1) in the two domains. They exhibit large tunability under an applied magnetic field or gate voltage, and clear signatures of nonreciprocity even under weak-coupling to evanescent photons. Topological kink modes are peculiar edge excitations that take place at domain boundaries of magnetic fields inside homogeneous materials. Here, the authors experimentally observe kink magnetoplasmons in a 2D electron gas using custom-shaped strong permanent magnets on top of a GaAs/AlGaAs heterojunction.
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Affiliation(s)
- Dafei Jin
- Nanoscale Science and Engineering Center, University of California, Berkeley, CA, 94706, USA.,Center for Nanoscale Materials, Argonne National Laboratory, Argonne, IL, 60439, USA
| | - Yang Xia
- Nanoscale Science and Engineering Center, University of California, Berkeley, CA, 94706, USA
| | - Thomas Christensen
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Matthew Freeman
- National High Magnetic Field Laboratory, Tallahassee, FL, 32310, USA
| | - Siqi Wang
- Nanoscale Science and Engineering Center, University of California, Berkeley, CA, 94706, USA
| | - King Yan Fong
- Nanoscale Science and Engineering Center, University of California, Berkeley, CA, 94706, USA
| | - Geoffrey C Gardner
- Microsoft Quantum Purdue and Birck Nanotechnology Center, Purdue University, West Lafayette, IN, 47907, USA
| | - Saeed Fallahi
- Department of Physics and Astronomy and Birck Nanotechnology Center, Purdue University, West Lafayette, IN, 47907, USA
| | - Qing Hu
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Yuan Wang
- Nanoscale Science and Engineering Center, University of California, Berkeley, CA, 94706, USA
| | - Lloyd Engel
- National High Magnetic Field Laboratory, Tallahassee, FL, 32310, USA
| | - Zhi-Li Xiao
- Material Science Division, Argonne National Laboratory, Argonne, IL, 60439, USA
| | - Michael J Manfra
- Microsoft Quantum Purdue, Department of Physics and Astronomy, Birck Nanotechnology Center, Schools of Electrical and Computer Engineering and Materials Engineering, Purdue University, West Lafayette, IN, 47907, USA
| | - Nicholas X Fang
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Xiang Zhang
- Nanoscale Science and Engineering Center, University of California, Berkeley, CA, 94706, USA. .,Faculties of Sciences and Engineering University of Hong Kong, Hong Kong SAR, PR, China.
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4
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Tanaka T, Kagamihata A. Demonstration of high-performance pole pieces made of monocrystalline dysprosium for short-period undulators. JOURNAL OF SYNCHROTRON RADIATION 2019; 26:1220-1225. [PMID: 31274447 DOI: 10.1107/s1600577519006052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Accepted: 04/30/2019] [Indexed: 06/09/2023]
Abstract
Reported here are the results of experiments carried out to demonstrate the magnetic performance of dysprosium (Dy) to enhance the capability of undulators. Tiny pieces of monocrystalline Dy surrounded by permanent magnets (PMs) work as pole pieces (PPs) to concentrate the magnetic flux, when cooled down below the Curie temperature of 85 K. A PP made of Dy is much more attractive than one made of a conventional material, because its saturation magnetization is much higher. Furthermore, it also allows for a more flexible selection of PM material, potentially leading to further enhancement of the performance of short-period undulators. Besides these advantages, practical issues related to using Dy PPs and countermeasures against them are discussed.
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Affiliation(s)
- Takashi Tanaka
- RIKEN SPring-8 Center, Koto 1-1-1, Sayo, Hyogo 679-5148, Japan
| | - Akihiro Kagamihata
- Japan Synchrotron Radiation Research Institute, Koto 1-1-1, Sayo, Hyogo 679-5198, Japan
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5
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Shaw G, Brisbois J, Pinheiro LBGL, Müller J, Blanco Alvarez S, Devillers T, Dempsey NM, Scheerder JE, Van de Vondel J, Melinte S, Vanderbemden P, Motta M, Ortiz WA, Hasselbach K, Kramer RBG, Silhanek AV. Quantitative magneto-optical investigation of superconductor/ferromagnet hybrid structures. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2018; 89:023705. [PMID: 29495853 DOI: 10.1063/1.5016293] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
We present a detailed quantitative magneto-optical imaging study of several superconductor/ferromagnet hybrid structures, including Nb deposited on top of thermomagnetically patterned NdFeB and permalloy/niobium with erasable and tailored magnetic landscapes imprinted in the permalloy layer. The magneto-optical imaging data are complemented with and compared to scanning Hall probe microscopy measurements. Comprehensive protocols have been developed for calibrating, testing, and converting Faraday rotation data to magnetic field maps. Applied to the acquired data, they reveal the comparatively weaker magnetic response of the superconductor from the background of larger fields and field gradients generated by the magnetic layer.
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Affiliation(s)
- G Shaw
- Experimental Physics of Nanostructured Materials, Q-MAT, CESAM, Université de Liège, B-4000 Sart Tilman, Belgium
| | - J Brisbois
- Experimental Physics of Nanostructured Materials, Q-MAT, CESAM, Université de Liège, B-4000 Sart Tilman, Belgium
| | - L B G L Pinheiro
- Departamento de Física, Universidade Federal de São Carlos, 13565-905 São Carlos, SP, Brazil
| | - J Müller
- Experimental Physics of Nanostructured Materials, Q-MAT, CESAM, Université de Liège, B-4000 Sart Tilman, Belgium
| | - S Blanco Alvarez
- Experimental Physics of Nanostructured Materials, Q-MAT, CESAM, Université de Liège, B-4000 Sart Tilman, Belgium
| | - T Devillers
- Univ. Grenoble Alpes, CNRS, Institut Néel, 38000, Grenoble, France
| | - N M Dempsey
- Univ. Grenoble Alpes, CNRS, Institut Néel, 38000, Grenoble, France
| | - J E Scheerder
- Laboratory of Solid-State Physics and Magnetism, KU Leuven, Celestijnenlaan 200 D, Box 2414, B-3001 Leuven, Belgium
| | - J Van de Vondel
- Laboratory of Solid-State Physics and Magnetism, KU Leuven, Celestijnenlaan 200 D, Box 2414, B-3001 Leuven, Belgium
| | - S Melinte
- Université catholique de Louvain, Institute of Information and Communication Technologies, Electronics and Applied Mathematics (ICTM), Institut de la Matière Condensée et des Nanosciences (IMCN), 1348 Louvain-la-Neuve, Belgium
| | - P Vanderbemden
- Université de Liège, SUPRATECS and Department of Electrical Engineering and Computer Science, Sart Tilman B-4000, Belgium
| | - M Motta
- Departamento de Física, Universidade Federal de São Carlos, 13565-905 São Carlos, SP, Brazil
| | - W A Ortiz
- Departamento de Física, Universidade Federal de São Carlos, 13565-905 São Carlos, SP, Brazil
| | - K Hasselbach
- Univ. Grenoble Alpes, CNRS, Institut Néel, 38000, Grenoble, France
| | - R B G Kramer
- Univ. Grenoble Alpes, CNRS, Institut Néel, 38000, Grenoble, France
| | - A V Silhanek
- Experimental Physics of Nanostructured Materials, Q-MAT, CESAM, Université de Liège, B-4000 Sart Tilman, Belgium
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6
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Chatterjee BK, Bhattacharjee K, Dey A, Ghosh CK, Chattopadhyay KK. Influence of spherical assembly of copper ferrite nanoparticles on magnetic properties: orientation of magnetic easy axis. Dalton Trans 2014; 43:7930-44. [DOI: 10.1039/c4dt00093e] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The spherical assembly of nanoparticles induces a high degree of alignment of magnetic easy axis as compared to randomly oriented nanoparticles which increases the reduced remanence ensuing straightened hysteresis loop.
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Affiliation(s)
- Biplab K. Chatterjee
- School of Materials Science and Nanotechnology
- Jadavpur University
- Kolkata 700032, India
| | | | - Abhishek Dey
- School of Materials Science and Nanotechnology
- Jadavpur University
- Kolkata 700032, India
| | - Chandan K. Ghosh
- School of Materials Science and Nanotechnology
- Jadavpur University
- Kolkata 700032, India
| | - Kalyan K. Chattopadhyay
- School of Materials Science and Nanotechnology
- Jadavpur University
- Kolkata 700032, India
- Thin Film and Nanoscience Laboratory
- Department of Physics
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7
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Andersson C, Sanyal B, Eriksson O, Nordström L, Karis O, Arvanitis D, Konishi T, Holub-Krappe E, Dunn JH. Influence of ligand states on the relationship between orbital moment and magnetocrystalline anisotropy. PHYSICAL REVIEW LETTERS 2007; 99:177207. [PMID: 17995367 DOI: 10.1103/physrevlett.99.177207] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2006] [Indexed: 05/25/2023]
Abstract
The spin and orbital moments of Au/Co/Au trilayers grown on a W(110) single crystal substrate have been investigated by means of x-ray magnetic circular dichroism. Our findings suggest that the orbital moment of Co does not obtain a maximum value along the easy axis, in contrast with previous experience. This is attributed to the large spin-orbit interaction within the Au caps. Both second order perturbation theory and first principles calculations show how the magnetocrystalline anisotropy (MCA) is dramatically influenced by this effect, and how this leads to the fact that the orbital moment anisotropy is not proportional to the MCA.
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Affiliation(s)
- C Andersson
- Department of Physics, Uppsala University, Box 530, 751 21 Uppsala, Sweden
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