01
Microscopic effective models
Construction of realistic Hubbard-type models and derivation of isotropic and anisotropic exchange interactions, including spin–orbit-coupling effects.
Theoretical condensed-matter physics
Ryota Ono 小野 凌太
Postdoctoral Fellow, Japan Atomic Energy Agency, Advanced Science Research Center
I derive effective spin, orbital, and electric-polarization models from realistic electronic-structure models to study magnetism and magnetoelectric phenomena in correlated materials.
Effective Hamiltonians
Multiferroics
Spin supersolids
Correlated magnets
Research
From electronic structure to emergent magnetic phenomena
My work combines first-principles electronic-structure calculations, Wannier-based many-body models, perturbative derivations of low-energy Hamiltonians, and numerical studies of quantum spin systems.
02
Magnetoelectric coupling
Microscopic theories of magnetically induced polarization and multiferroicity, with an emphasis on atomic orbitals, crystal symmetry, and electronic correlations.
03
Quantum spin phases
Effective-model studies of triangular-lattice magnets, spin supersolids, spin–orbit-coupled systems, and finite-temperature magnetic interactions.
Current directions
Research in progress
Spin supersolids
A microscopic design rule for triangular-lattice magnets
Relating trigonal crystal fields, spin–orbit coupling, and XXZ anisotropy in Co-based candidate materials.
Read the preprintOrbital and ferroelectric order
Entangled orders in the p-electron magnet CsO2
Microscopic modeling of coupled orbital, magnetic, and ferroelectric phenomena in an unconventional molecular magnet.
Read the preprintFinite-temperature magnetism
Magnetic interactions beyond zero temperature
Development of a first-principles framework for finite-temperature magnetic interactions in correlated materials.
Under reviewPublications
Selected work
2026
A Microscopic Design Rule for Spin Supersolids in Triangular-Lattice Magnets
R. Ono, J. Ieda, M. Mori, and S. Maekawa
arXiv:2606.06111
2024
Ferromagnetic Ferroelectricity due to the Kugel–Khomskii Mechanism of the Orbital Ordering Assisted by Atomic Hund’s Second-Rule Effects
I. Solovyev, R. Ono, and S. Nikolaev
Physical Review B 110, 205116 — Editor’s Suggestion
2024
Multiferroic Kinks and Spin-Flop Transition in Ni2InSbO6 from First Principles
R. Ono, I. Solovyev, and S. Artyukhin
npj Spintronics 2, 17
2022
Room-Temperature Type-II Multiferroic Phase Induced by Pressure in Cupric Oxide
N. Terada et al., including R. Ono
Physical Review Letters 129, 217601
2021
Magnetically Induced Polarization in Centrosymmetric Bonds
I. Solovyev, R. Ono, and S. Nikolaev
Physical Review Letters 127, 187601
2020
Fingerprints of Spin-Current Physics on Magnetoelectric Response in the Spin-1/2 Magnet Ba2CuGe2O7
R. Ono, S. Nikolaev, and I. Solovyev
Physical Review B 102, 064422
Experience
Academic appointments
2025–present
Japan Atomic Energy Agency, Advanced Science Research Center
Postdoctoral Fellow
2023–2025
National Institute for Materials Science
JSPS Research Fellow
2021–2023
Istituto Italiano di Tecnologia
Postdoctoral Fellow
2021
Chiba University
Ph.D. in Science
Contact
Ryota Ono
Advanced Science Research Center, Room 323
Japan Atomic Energy Agency
2-4 Shirakata, Tokai-mura, Naka-gun
Ibaraki 319-1195, Japan