井上 天 (イノウエ タカシ)

理学研究院 物理学部門 凝縮系物理学分野助教

研究者基本情報

■ 学位
  • 博士(理学), 北海道大学, 2023年03月
■ URL
researchmap URLホームページURL■ ID 各種
研究者番号
  • 71021250
ORCID IDJ-Global ID■ 研究キーワード・分野
研究分野
  • 自然科学一般, 数理物理、物性基礎
  • 自然科学一般, 磁性、超伝導、強相関系
■ 担当教育組織

研究活動情報

■ 論文
  • Raman Characterization of Two-Dimensional Quasiperiodic Antiferromagnets on Various Lattices: Spin–Orbit Mechanism
    Takashi Inoue; Shoji Yamamoto
    Journal of the Physical Society of Japan, 95, 6, Physical Society of Japan, 2026年06月15日, [査読有り]
    研究論文(学術雑誌)
  • Superconfined Antiferromagnons on the Two-Dimensional Penrose Lattice
    Takashi Inoue; Shoji Yamamoto
    Crystals, 16, 6, 370, 370, MDPI AG, 2026年06月01日, [査読有り]
    英語, 研究論文(学術雑誌), We find novel confined states in the spin-S nearest-neighbor antiferromagnetic Heisenberg model on the two-dimensional Penrose lattice. Linear spin waves have massively degenerate eigenstates strictly confined to tricoordinated sites. They contrast with the well-known itinerant analogs in the tight-binding model, where electrons are confined but extended to both tricoordinated and pentacoordinated sites. It is the site potentials in the spin-wave Hamiltonian, originating from Coulomb interactions between electrons, that confine spin waves to minimally coordinated sites only. Confined states in the tight-binding Hamiltonian consist of six types of building blocks, whereas those in the spin-wave Hamiltonian consist of only four of them. Confined spin waves are robust against 1/S corrections. Emergent O(S0) interactions further confine—superconfine—spin waves into two separate groups within tricoordinated sites.
  • Magnon Confinement on the Two-Dimensional Penrose Lattice: Perpendicular-Space Analysis of the Dynamic Structure Factor
    Shoji Yamamoto; Takashi Inoue
    Crystals, 14, 8, 702, 702, MDPI AG, 2024年08月01日, [査読有り]
    英語, 研究論文(学術雑誌), Employing the spin-wave formalism within and beyond the harmonic-oscillator approx-imation, we study the dynamic structure factors of spin-12 nearest-neighbor quantum Heisenberg antiferromagnets on two-dimensional quasiperiodic lattices with particular emphasis on a mag-netic analog to the well-known confined states of a hopping Hamiltonian for independent electrons on a two-dimensional Penrose lattice. We present comprehensive calculations on the C5v Penrose tiling in comparison with the C8v Ammann–Beenker tiling, revealing their decagonal and octagonal antiferromagnetic microstructures. Their dynamic spin structure factors both exhibit linear soft modes emergent at magnetic Bragg wavevectors and have nearly or fairly flat scattering bands, signifying magnetic excitations localized in some way, at several different energies in a self-similar manner. In particular, the lowest-lying highly flat mode is distinctive of the Penrose lattice, which is mediated by its unique antiferromagnons confined within tricoordinated sites only, unlike their itinerant electron counterparts involving pentacoordinated, as well as tricoordinated, sites. Bringing harmonic antiferromagnons into higher-order quantum interaction splits, the lowest-lying nearly flat scattering band in two, each mediated by further confined antiferromagnons, which is fully demonstrated and throughly visualized in the perpendicular as well as real spaces. We disclose superconfined antiferromagnons on the two-dimensional Penrose lattice.
  • Polarized Raman Response of Two-Dimensional Quasiperiodic Antiferromagnets: Configuration-Interaction versus Green’s Function Approaches
    Takashi Inoue; Shoji Yamamoto
    Journal of the Physical Society of Japan, 91, 5, Physical Society of Japan, 2022年05月15日, [査読有り]
    英語, 研究論文(学術雑誌)
  • Optical Observation of Quasiperiodic Heisenberg Antiferromagnets in Two Dimensions
    Takashi Inoue; Shoji Yamamoto
    physica status solidi (b), 2020年11月, [査読有り]
    研究論文(学術雑誌)
■ その他活動・業績
■ 講演・口頭発表等
  • Spin-orbit-coupling-driven Raman scattering in two-dimensional quasiperiodic and periodic XXZ antiferromagnets
    井上天; 山本昌司
    日本物理学会 第80回年次大会, 2025年09月17日, 日本語, 口頭発表(一般)
    2025年09月15日 - 2025年09月19日
  • Optical observations of two-dimensional quasiperiodic antiferromagnets
    井上天
    新学術領域「ハイパーマテリアル:補空間が創る新物質科学」第29回ハイパーマテリアル・セミナー, 2023年07月, 日本語, 公開講演,セミナー,チュートリアル,講習,講義等
    [招待講演]
  • Magnon localization in the two-dimensional Penrose antiferromagnet: Perpendicular-space analysis of the dynamic structure factor
    井上天; 山本昌司
    日本物理学会 2023年春季大会, 2023年03月, 口頭発表(一般)
  • Perpendicular-space analysis of one-magnon-mediated Raman scattering in quasiperiodic antiferromagnets
    井上天; 山本昌司
    日本物理学会 第76回年次大会, 2021年03月, 日本語, 口頭発表(一般)
  • Optical observation of quasiperiodic Heisenberg antiferromagnets in two dimensions
    Takashi Inoue; Shoji Yamamoto
    14th International Conference on the Structure of Non-Crystalline Materials (NCM14), 2019年11月, 英語, 口頭発表(一般)
  • One- and two-magnon-mediated Raman scattering in Penrose-lattice antiferromagnets
    井上天; 山本昌司
    日本物理学会 2019年秋季大会, 2019年09月, 日本語, 口頭発表(一般)
  • Spin-chirality-driven Raman scattering in Penrose-lattice Heisenberg antiferromagnets
    Takashi Inoue; Shoji Yamamoto
    Interdisciplinary Symposium for Quasicrystals and Strongly Correlated Electron Systems (QSC2019), 2019年06月, 英語, ポスター発表
  • Penrose格子Heisenberg反強磁性体の超Loudon-Fleury磁気Raman散乱理論
    井上天; 山本昌司
    日本物理学会 第74回年次大会, 2019年03月, 日本語, 口頭発表(一般)
  • 2次元準周期Heisenberg反強磁性体の磁気Raman散乱
    井上天; 山本昌司
    日本物理学会 2018年秋季大会, 2018年09月, 口頭発表(一般)
  • 反強磁性スピン・チューブの磁気Raman散乱理論
    井上天; 山本昌司
    日本物理学会 第71回年次大会, 2016年03月, 口頭発表(一般)
  • 異方的量子スピン模型のSchwingerボソン解析
    井上天; 山本昌司
    日本物理学会 2015年秋季大会, 2015年09月, 口頭発表(一般)
■ 所属学協会
  • 2015年06月 - 現在
    日本物理学会