A5013873940- Advanced Condensed Matter Physics
- Magnetic and transport properties of perovskites and related materials
- Physics of Superconductivity and Magnetism
- Electronic and Structural Properties of Oxides
- Topological Materials and Phenomena
- Magnetic properties of thin films
- Quantum and electron transport phenomena
- Multiferroics and related materials
- Rare-earth and actinide compounds
- Quantum many-body systems
- Theoretical and Computational Physics
- 2D Materials and Applications
- Metallic Glasses and Amorphous Alloys
- Magnetic Properties of Alloys
- Endometrial and Cervical Cancer Treatments
- Magnetic Properties and Applications
- High-pressure geophysics and materials
- X-ray Diffraction in Crystallography
- Crystallization and Solubility Studies
- Silicon and Solar Cell Technologies
- Organic and Molecular Conductors Research
- Magnetism in coordination complexes
- Iron-based superconductors research
- Graphene research and applications
- Advanced Chemical Physics Studies
Oak Ridge National Laboratory
2016-2025
Tohoku University
2006-2023
National Institute for Materials Science
2022-2023
Quantum Science Center
2021-2022
Spintronics Research Network of Japan
2022
ORCID
2021
Institut Laue-Langevin
2021
Hosei University
2017
Hokkaido University
1993-2014
Material (Belgium)
2004-2011
We report the connection between stacking order and magnetic properties of bilayer CrI$_3$ using first-principles calculations. show that defines ground state. By changing interlayer one can tune exchange interaction antiferromagnetic ferromagnetic. To measure predicted stacking-dependent magnetism, we propose linear magnetoelectric effect. Our results not only gives a possible explanation for observed antiferromagnetism in but also have direct implications heterostructures made...
Layered transition metal trichalcogenides with the chemical formula $ABX_3$ have attracted recent interest as potential candidates for two-dimensional magnets. Using first-principles calculations within density functional theory, we investigate magnetic ground states of monolayers Mn- and Cr-based semiconducting trichalcogenides. We show that second third nearest-neighbor exchange interactions ($J_2$ $J_3$) between ions, which been largely overlooked in previous theoretical studies, are...
We report the formation of a novel ferromagnetic state in antiferromagnet ${\mathrm{BiFeO}}_{3}$ at interface with ferromagnet ${\mathrm{La}}_{0.7}{\mathrm{Sr}}_{0.3}{\mathrm{MnO}}_{3}$. Using x-ray magnetic circular dichroism Mn and Fe ${L}_{2,3}$ edges, we discovered that development this spin structure is strongly associated onset significant exchange bias. Our results demonstrate directly related to an electronic orbital reconstruction interface, which supported by linearly polarized...
Epitaxial oxide interfaces with broken translational symmetry have emerged as a central paradigm behind the novel behaviors of superlattices. Here, we use scanning transmission electron microscopy to demonstrate direct, quantitative unit-cell-by-unit-cell mapping lattice parameters and oxygen octahedral rotations across ${\mathrm{BiFeO}}_{3}\mathrm{\text{\ensuremath{-}}}{\mathrm{La}}_{0.7}{\mathrm{Sr}}_{0.3}{\mathrm{MnO}}_{3}$ interface elucidate how change crystal is accommodated. Combined...
In a collinear antiferromagnet with easy-axis anisotropy, symmetry guarantees that the spin wave modes are doubly degenerate. The two carry opposite angular momentum and exhibit chirality. Using honeycomb in presence of Dzyaloshinskii-Moriya interaction, we show longitudinal temperature gradient can drive to transverse directions, realizing Nernst effect magnons vanishing thermal Hall current. We find around $\mathrm{\ensuremath{\Gamma}}$ point $K$ contribute oppositely transport, their...
Abstract Spin fluctuation and transition have always been one of the central topics magnetism condensed matter science. Experimentally, spin is found transcribed onto scattering intensity in neutron-scattering process, which represented by dynamical magnetic susceptibility maximized at phase transitions. Importantly, a neutron carries without electric charge, therefore it can bring into sample being disturbed energy. However, large facilities such as nuclear reactor are necessary. Here we...
Here, the authors report a thorough study of evolution structural, magnetic, and electrical properties MnBi${}_{2\ensuremath{-}x}$Sb${}_{x}$Te${}_{4}$ single crystals. This investigation reveals an intimate correlation between transport properties. Partial substitution Bi by Sb is effective approach to tuning both magnetism Fermi level, which are two key components magnetic topological insulators. work provides important guide for exploring in MnBi${}_{2}$Te${}_{4}$-based materials. The...
A lightly doped manganite ${\mathrm{La}}_{0.88}{\mathrm{Sr}}_{0.12}{\mathrm{MnO}}_{3}$ exhibits a phase transition at ${T}_{\mathrm{OO}}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}145\phantom{\rule{0ex}{0ex}}\mathrm{K}$ from ferromagnetic metal ( ${T}_{C}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}172\phantom{\rule{0ex}{0ex}}\mathrm{K}$) to novel insulator. We identify that the key parameter in is orbital degree of freedom ${e}_{g}$ electrons. By utilizing resonant x-ray...
Local density approximation + Hubbard U and many-body effective Hamiltonian calculations are used to determine the effects of lattice relaxation in LaTiO3/SrTiO3 superlattices. Large ferroelectric-like distortions TiO6 octahedra found, which substantially affect Ti d-electron density, bringing calculated results into good agreement with experimental data. The relaxations also change physics, leading a novel symmetry-breaking-induced ordering xy orbitals, does not occur bulk LaTiO3, or...
We have investigated the changes occurring in electronic structure of digitally controlled SrVO(3) ultrathin films across metal-insulator transition (MIT) by film thickness using situ photoemission spectroscopy. With decreasing thickness, a pseudogap is formed at E(F) through spectral weight transfer from coherent part to incoherent part. The finally evolves into an energy gap that indicative MIT film. observed behavior reproduced layer dynamical-mean-field-theory calculations, and it...
We use the variational mean-field approach to systematically study phase diagram of a bilayer heterostructure correlated transition metal oxide LaNiO3, grown along (111) direction. The Ni 3+ ions with d7 (or eg1) configuration form buckled honeycomb lattice. show that as function strength on-site interactions, various topological phases emerge. In presence reasonable size Hund's coupling, correlation is tuned from intermediate strong, following sequence found: (1) Dirac half-semimetal phase,...
We investigate the electronic reconstruction in (LaNiO$_{3}$)$_n$/(LaAlO$_{3}$)$_3$ (n=3, 5 and 10) superlattices due to quantum confinement (QC) by d.c. transport resonant soft x-ray absorption spectroscopy. In proximity QC limit, a Mott-type transition from an itinerant electron behavior localized state is observed. The system exhibits tendency towards charge-order during transition. ab initio cluster calculations are good agreement with spectra, indicating that apical ligand hole density...
We propose an unexplored class of absorbing materials for high-efficiency solar cells: heterostructures transition-metal oxides. In particular, LaVO_3 grown on SrTiO_3 has a direct band gap ~1.1 eV in the optimal range as well internal potential gradient, which can greatly help to separate photo-generated electron-hole pairs. Furthermore, oxide afford flexibility combine with other such LaFeO_3 order achieve even higher efficiencies band-gap graded cells. use density-functional theory...
Using symmetry arguments and a tight-binding model, we show that for layered collinear antiferromagnets, magneto-optic effects can be generated manipulated by controlling crystal symmetries through gate voltage. This provides promising route electric field manipulation of the without modifying underlying magnetic structure. We further demonstrate control Kerr effect (MOKE) in bilayer ${\mathrm{MnPSe}}_{3}$ using first-principles calculations. The field-induced inversion breaking leads to...
We propose a new mechanism for the thermal Hall effect in exchange spin-wave systems, which is induced by magnon-phonon interaction. Using symmetry arguments, we first show that this quite general, and exists whenever mirror direction of magnetization broken. then demonstrate our result collinear ferromagnet on square lattice, with perpendicular easy-axis anisotropy Dzyaloshinskii-Moriya interaction from breaking. conductivity controlled resonant contribution anti-crossing points between...
Quantum interference on the kagome lattice generates electronic bands with narrow bandwidth, called flat bands. Crystal structures incorporating this can host strong electron correlations non-standard ingredients, but only if these lie at Fermi level. In six compounds CoSn structure type (FeGe, FeSn, CoSn, NiIn, RhPb, and PtTl) transition metals form a lattice. The two iron variants are robust antiferromagnets so we focus latter four investigate their thermodynamic transport properties. We...
Abstract What is the correct low-energy spin Hamiltonian description of $$\alpha$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>α</mml:mi> </mml:math> -RuCl $$_{3}$$ <mml:msub> <mml:mrow /> <mml:mrow> <mml:mn>3</mml:mn> </mml:mrow> </mml:msub> ? The material a promising Kitaev liquid candidate, but also known to order magnetically, which necessitates additional interaction terms. nature these interactions, their magnitudes and even signs, remain an open question. In this...
We demonstrate how quantum entanglement can be directly witnessed in the quasi-1D Heisenberg antiferromagnet KCuF$_3$. apply three witnesses --- one-tangle, two-tangle, and Fisher information to its inelastic neutron spectrum, compare with spectra simulated by finite-temperature density matrix renormalization group (DMRG) classical Monte Carlo methods. find that each witness provides direct access entanglement. Of these, is most robust experimentally, indicates presence of at least bipartite...
The lack of methods to experimentally detect and quantify entanglement in quantum matter impedes our ability identify materials hosting highly entangled phases, such as spin liquids. We thus investigate the feasibility using inelastic neutron scattering (INS) implement a model-independent measurement protocol for based on three witnesses: one-tangle, two-tangle, Fisher information (QFI). perform high-resolution INS measurements Cs$_2$CoCl$_4$, close realization $S=1/2$ transverse-field XXZ...
The intertwining between spin, charge, and lattice degrees of freedom can give rise to unusual macroscopic quantum states, including high-temperature superconductivity anomalous Hall effects. Recently, a charge density wave (CDW) has been observed in the kagome antiferromagnet FeGe, indicative possible physics. An outstanding question is that whether magnetic correlation fundamental for spontaneous spatial symmetry breaking orders. Here, utilizing elastic high-resolution inelastic x-ray...