Article
Chemistry, Physical
Xiang-Lin Huang, Sz-Chian Liou, Tan-Ju Yang, Hsin-An Chen, Hsiao-Wen Chen, Hsiang-Lin Liu, Wei-Tin Chen, Guo-Jiun Shu
Summary: Photocatalysis is a potential solution to energy shortage and greenhouse effect. CuFeO2 (CFO) is a material with a Delafossite structure and has been studied extensively. In this study, we successfully grew high-quality CFO single crystals using the optical floating-zone technique. CFO has a narrow band gap, high charge carrier mobility, and electrochemical stability. The magnetic phase transition and magnetic entropy change of CFO were also investigated.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Multidisciplinary Sciences
Sergi Lendinez, Mojtaba T. Kaffash, Olle G. Heinonen, Sebastian Gliga, Ezio Iacocca, M. Benjamin Jungfleisch
Summary: We have discovered the existence of nonlinear magnon-magnon scattering processes and their coherence in ensembles of magnetic nanostructures known as artificial spin ice. Utilizing a combined microwave and microfocused Brillouin light scattering measurement approach, we have found that these systems exhibit effective scattering processes akin to those observed in continuous magnetic thin films. Our results suggest that frequency doubling is enabled by exciting a subset of nanomagnets that act as nanosized antennas, which is similar to scattering in continuous films. Furthermore, directional scattering could be possible in these structures.
NATURE COMMUNICATIONS
(2023)
Article
Physics, Multidisciplinary
Zhongqiang Hu, Liang Fu, Luqiao Liu
Summary: In antiparallelly aligned magnetic multilayers, the long-range, chiral dipolar interaction between propagating magnons generates bulk bands with nonzero Chern integers and magnonic surface states carrying chiral spin currents. The surface states are highly localized and can be easily toggled between nontrivial and trivial phases through an external magnetic field.
PHYSICAL REVIEW LETTERS
(2022)
Article
Multidisciplinary Sciences
Shantanu Mishra, Goncalo Catarina, Fupeng Wu, Ricardo Ortiz, David Jacob, Kristjan Eimre, Ji Ma, Carlo A. Pignedoli, Xinliang Feng, Pascal Ruffieux, Joaquin Fernandez-Rossier, Roman Fasel
Summary: By using scanning tunnelling microscopy and spectroscopy, fractional edge excitations are observed in nanographene spin chains, providing a new approach to study strongly correlated phases in purely organic materials.
Article
Chemistry, Multidisciplinary
Kirill O. Nikolaev, Stephanie R. Lake, Georg Schmidt, Sergej O. Demokritov, Vladislav E. Demidov
Summary: This study successfully demonstrates spin-wave devices that can operate without an external magnetic field using submicrometer wide waveguides. The experimental results show that these waveguides have a highly stable magnetic configuration at zero field and support long-range propagation of spin waves. These findings provide the basis for the development of energy-efficient zero-field spin-wave devices and circuits.
Article
Materials Science, Multidisciplinary
Zachary M. Raines, Dmitrii L. Maslov, Leonid I. Glazman
Summary: In this study, we discovered the existence of generalized Silin modes in a multivalley system, monolayer graphene, and investigated their excitation in the spin and valley-staggered-spin channels, as well as their contributions to the optical conductivity.
Article
Materials Science, Multidisciplinary
Y. Shimamoto, F. J. T. Goncalves, T. Sogo, Y. Kousaka, Y. Togawa
Summary: The study found that the characteristics of microwave propagation can be significantly influenced by adjusting the number of chiral solitons and the direction of the magnetic field in the CSL phase, opening up a new avenue for controlling microwave propagation characteristics using noncollinear spin textures.
Article
Multidisciplinary Sciences
Sangjun Lee, Edwin W. Huang, Thomas A. Johnson, Xuefei Guo, Ali A. Husain, Matteo Mitrano, Kannan Lu, Alexander Zakrzewski, Gilberto A. de la Pena, Yingying Peng, Hai Huang, Sang-Jun Lee, Hoyoung Jang, Jun-Sik Lee, Young Il Joe, William B. Doriese, Paul Szypryt, Daniel S. Swetz, Songxue Chi, Adam A. Aczel, Gregory J. MacDougall, Steven A. Kivelson, Eduardo Fradkin, Peter Abbamonte
Summary: The behavior of charge density waves (CDWs) in different families of copper-oxide superconductors has been studied. This research found that the CDW amplitude is temperature independent and develops well above experimentally accessible temperatures. The CDW wavevector shows a nonmonotonic temperature dependence, exhibiting different behaviors at low temperatures and near the spin ordering temperature. The study suggests a common mechanism for CDW order in all families of cuprates.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)
Article
Nanoscience & Nanotechnology
Andrii S. Savchenko, Vladyslav M. Kuchkin, Filipp N. Rybakov, Stefan Bluegel, Nikolai S. Kiselev
Summary: This study investigates the resonance excitations of three-dimensional skyrmions lattice in a finite thickness plate of an isotropic chiral magnet, revealing differences from predictions of two-dimensional and unconfined bulk crystal models in terms of absorption spectra and resonance modes.
Article
Multidisciplinary Sciences
G. Poelchen, J. Hellwig, M. Peters, D. Yu. Usachov, K. Kliemt, C. Laubschat, P. M. Echenique, E. V. Chulkov, C. Krellner, S. S. P. Parkin, D. V. Vyalikh, A. Ernst, K. Kummer
Summary: The metallic antiferromagnet CeCo2P2 exhibits long-lived spin-waves at terahertz frequencies, suggesting the potential use of metallic antiferromagnets for spin-wave information processing.
NATURE COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Raisa Fabiha, Jonathan Lundquist, Sudip Majumder, Erdem Topsakal, Anjan Barman, Supriyo Bandyopadhyay
Summary: This study investigates the tripartite coupling between phonons, magnons, and photons in a periodic array of elliptical magnetostrictive nanomagnets on a piezoelectric substrate to form a 2D two-phase multiferroic crystal. The phonons launch surface acoustic waves (SAW) that cause the spin-wave modes (magnons) within the nanomagnets to radiate electromagnetic waves (photons). This phonon-magnon-photon coupling is exploited to implement an extreme sub-wavelength electromagnetic antenna with significantly higher radiation efficiency and antenna gain compared to traditional antennas of the same size.
Article
Chemistry, Multidisciplinary
Rodolfo A. Gallardo, Pablo Alvarado-Seguel, Felipe Brevis, Alejandro Roldan-Molina, Kilian Lenz, Juergen Lindner, Pedro Landeros
Summary: Magnetization-graded ferromagnetic nanostrips are proposed as potential candidates for guiding spin waves. The study investigates the spin-wave transport behavior in these nanostrips by simulating and analyzing the effects of saturation magnetization profile. The findings demonstrate the feasibility of achieving remarkable channeling of spin waves even with a small reduction in saturation magnetization.
Article
Physics, Fluids & Plasmas
Hongjuan Meng, Jing Wang, Xiaobei Fan, Qingqing Wang, Kaihua Shao, Yuexin Zhao, Wenyuan Wang, Yuren Shi
Summary: This paper investigates the existence and stability of vector gap solitons in systems with spin-orbit coupling and honeycomb optical lattices. The study shows that the properties of interspin and intraspin atomic interactions have a significant impact on the existence and stability of vector gap solitons. The phase diagram of stable and unstable vector gap solitons is obtained based on the direct evolution dynamics.
Article
Chemistry, Physical
Jonathan Pelliciari, Sangjae Lee, Keith Gilmore, Jiemin Li, Yanhong Gu, Andi Barbour, Ignace Jarrige, Charles H. Ahn, Frederick J. Walker, Valentina Bisogni
Summary: Resonant inelastic X-ray scattering was used to investigate the spectrum of spin excitations in mesoscopic Fe films, revealing that as the thickness is reduced, ferromagnetic spin excitations in the films renormalize to lower energies along the out-of-plane direction while maintaining their dispersion in the in-plane direction. This thickness dependence was explained by Heisenberg model calculations considering the confinement in the out-of-plane direction caused by the loss of Fe bonds.
Article
Physics, Multidisciplinary
Y. Shimamoto, Y. Matsushima, T. Hasegawa, Y. Kousaka, I Proskurin, J. Kishine, A. S. Ovchinnikov, F. J. T. Goncalves, Y. Togawa
Summary: Chiral spin soliton lattices (CSL), which exhibit reconfigurability and controllability, can generate phononlike elementary excitations. In this study, higher-order magnetic resonance modes were observed in the CSL phase of a chiral helimagnet through experiments. The resonance frequency of the CSL phonon can be adjusted, making chiral helimagnets potentially useful for broadband signal processing in the millimeter-wave band.
PHYSICAL REVIEW LETTERS
(2022)
Article
Physics, Condensed Matter
Liurukara D. Sanjeewa, Yaohua Liu, Jie Xing, Randy S. Fishman, Mudithangani T. K. Kolambage, Michael A. McGuire, Colin D. McMillen, Joseph W. Kolis, Athena S. Sefat
Summary: The synthesis, structure, and physical properties of Y5Ru2O12, a new member of the Ln(5)B(2)O(12) class, were reported. Single crystals of Y(5)Ru(2)O(12) were synthesized using a high-temperature, high-pressure hydrothermal method, exhibiting a complex 3D structure and antiferromagnetic behavior.
PHYSICA STATUS SOLIDI B-BASIC SOLID STATE PHYSICS
(2021)
Article
Chemistry, Inorganic & Nuclear
Kendall D. Hughey, Minseong Lee, Jisoo Nam, Amanda J. Clune, Kenneth R. O'Neal, Wei Tian, Randy S. Fishman, Mykhaylo Ozerov, JunHee Lee, Vivien S. Zapf, Janice L. Musfeldt
Summary: In this study, high field polarization, magneto-infrared spectroscopy, and lattice dynamics calculations were used to investigate the properties of (NH4)(2)[FeCl5 center dot(H2O)] - a type II molecular multiferroic. The results showed that the electric polarization is sensitive to the field-induced spin reorientations, and the magnetoelectric coupling occurs through an orbital hybridization mechanism. Magneto-infrared spectroscopy revealed that all vibrational modes below 600 cm(-1) are sensitive to the field-induced transition to the fully saturated magnetic state. Additionally, subtle symmetry breaking of the counterions was observed across the ferroelectric transition.
INORGANIC CHEMISTRY
(2022)
Article
Physics, Condensed Matter
Randy S. Fishman, George Ostrouchov, Feng Ye
Summary: This work presents two methods for fitting the inelastic neutron-scattering spectrum S(q, omega) with wavevector q and frequency omega. The first method extracts experimental spin-wave branches from the measured spectra and compares the observed and predicted frequencies. The second method directly compares the measured and predicted intensities over a grid in wavevector and frequency space. The advantages and disadvantages of each approach are demonstrated by studying the open honeycomb material Tb2Ir3Ga9.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2022)
Article
Materials Science, Multidisciplinary
Duncan H. Moseley, Keith M. Taddei, Jiaqiang Yan, Michael A. McGuire, Stuart Calder, M. M. H. Polash, Daryoosh Vashaee, Xiaofan Zhang, Huaizhou Zhao, David S. Parker, Randy S. Fishman, Raphael P. Hermann
Summary: This research demonstrates that a small amount of lithium doped into MnTe can cause a significant spin reorientation, thereby paving the way for easy switching of magnetic states in functional materials such as spintronic devices and topological insulators.
PHYSICAL REVIEW MATERIALS
(2022)
Article
Physics, Condensed Matter
Randy S. Fishman, Lucas Lindsay, Satoshi Okamoto
Summary: We calculate the orbital angular momentum (OAM) of magnons at the high symmetry points of ferromagnetic (FM) and antiferromagnetic (AF) honeycomb lattices with Dzyaloshinskii-Moriya (DM) interactions. For the FM lattice, in the absence of DM interactions, the OAM values at the corners of the Brillouin zone are alternately +/- 3h/16 for both magnon bands. The presence of DM interactions breaks this degeneracy and changes the OAM values significantly. For the AF lattice, the OAM values at the corners of the Brillouin zone depend on the anisotropy kappa and are independent of the DM interaction.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2023)
Article
Physics, Multidisciplinary
Randy S. Fishman, Jason S. Gardner, Satoshi Okamoto
Summary: This study investigates the orbital angular momentum of magnons in collinear ferromagnetic and antiferromagnetic systems with nontrivial networks of exchange interactions. The results show that the orbital angular momentum of magnons becomes nonzero in zigzag and honeycomb lattices when the lattice contains two inequivalent sites and reaches its peak at avoided-crossing points or extremum of the frequency bands. Thus, the arrangement of exchange interactions may play a more significant role in generating the orbital angular momentum of magnons compared to spin-orbit coupling energy and the resulting noncollinear arrangement of spins.
PHYSICAL REVIEW LETTERS
(2022)
Correction
Physics, Multidisciplinary
Randy S. Fishman, Jason S. Gardner, Satoshi Okamoto
PHYSICAL REVIEW LETTERS
(2023)
Article
Materials Science, Multidisciplinary
Randy S. Fishman
Summary: In this study, the gauge invariance of orbital angular momentum (OAM) and average OAM for magnons with different phases is investigated. It is found that a gauge-invariant function can be constructed by integrating over the direction of wave vector. The average OAM is directly observable.
Article
Chemistry, Inorganic & Nuclear
Liurukara D. Sanjeewa, V. Ovidiu Garlea, Keith M. Taddei, Li Yin, Jie Xing, Randy S. Fishman, David S. Parker, Athena S. Sefat
Summary: This article reports the synthesis and characterization of a new material, NaCo2(SeO3)(2)(OH), which has a highly frustrated sublattice of sawtooth Co2+ chains. The material shows both ferromagnetic and antiferromagnetic transitions at different temperatures, and neutron scattering measurements reveal the spin excitations in the material.
INORGANIC CHEMISTRY FRONTIERS
(2022)
Article
Materials Science, Multidisciplinary
Depei Zhang, Sachith Dissanayake, Barry Winn, Masaaki Matsuda, Toshimitsu Ito, Randy Fishman
Summary: Polarized inelastic neutron-scattering experiments were conducted to investigate the anisotropic behavior of low-energy spin-wave excitations in a multiferroic BiFeO3. The study successfully separated magnetic excitation modes below 6 meV in and out of the cycloidal plane, and identified several magnon modes including two anisotropic modes that were previously observed using optical spectroscopies. The research also discovered other magnon modes that are not active in optical measurements.
Meeting Abstract
Chemistry, Multidisciplinary
W. Tian, R. S. Fishman, H. B. Cao, G. Sala, D. M. Pajerowski, V. O. Garlea, T. Hong, L. L. Daemen, Y. Q. Cheng, J. A. Fernandez-Baca
ACTA CRYSTALLOGRAPHICA A-FOUNDATION AND ADVANCES
(2021)
Article
Materials Science, Multidisciplinary
G. Pokharel, H. Suriya Arachchige, S. Gao, S-H Do, R. S. Fishman, G. Ehlers, Y. Qiu, J. A. Rodriguez-Rivera, M. B. Stone, H. Zhang, S. D. Wilson, D. Mandrus, A. D. Christianson
Summary: The study investigates the spin excitations in GaV4S8 through inelastic neutron scattering measurements and describes the spin wave excitations using linear spin wave theory. The research clarifies the spin interactions in GaV4S8 and supports the picture of interacting molecular clusters.
Article
Materials Science, Multidisciplinary
D. G. Farkas, D. Szaller, I Kezsmarki, U. Nagel, T. Room, L. Peedu, J. Viirok, J. S. White, R. Cubitt, T. Ito, R. S. Fishman, S. Bordacs
Summary: The magnetic-field dependence of THz absorption and nonreciprocal directional dichroism spectra of BiFeO3 was investigated, revealing optical selection rules of spin-wave excitations and the effects of in-plane magnetic fields on cycloidal q vectors. Changes in strength and frequency of spin-wave modes were observed with the orientation and length of the q vector, with experimental data compared to linear spin-wave theory to identify relevant spin-polarization coupling terms for the optical magnetoelectric effect.
Article
Materials Science, Multidisciplinary
Seamus Beairsto, Maximilien Cazayous, Randy S. Fishman, Rogerio de Sousa
Summary: The study develops a theory to calculate the confined magnon spectra and its associated spin scattering function, showing that extra anisotropy at the surface or interface plays a key role in magnon confinement. The research reveals that the confinement of magnons is qualitatively similar for ferromagnets and antiferromagnets in dimensions d >= 2, with remarkable differences between the two in one dimension.
Article
Physics, Multidisciplinary
Tom Berlijn, Gonzalo Alvarez, David S. Parker, Raphael P. Hermann, Randy S. Fishman
Summary: The study investigates the magnetic ground state and spin-wave excitations of the entropy stabilized oxide Mg0.2Co0.2Ni0.2Cu0.2Zn0.2O, revealing that the antiferromagnetic structure can be stabilized by a rhombohedral distortion and large second-nearest-neighbor interactions. The spin-wave spectrum consists of a coherent low-energy spectrum and an incoherent continuum extending to higher energies.
PHYSICAL REVIEW RESEARCH
(2021)
