動的平均場理論を用いた共鳴非弾性X線散乱のマルチスケール解析手法の開発と応用

• Project/Area Number: 21K13884
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 13030:Magnetism, superconductivity and strongly correlated systems-related
• Research Institution: Osaka Metropolitan University (2022-2023); Osaka Prefecture University (2021)
• Principal Investigator: 播木 敦 大阪公立大学, 大学院工学研究科, 准教授 (90875783)
• Project Period (FY): 2021-04-01 – 2025-03-31
• Project Status: Granted (Fiscal Year 2023)
• Budget Amount: ¥4,550,000 (Direct Cost: ¥3,500,000、Indirect Cost: ¥1,050,000); Fiscal Year 2024: ¥520,000 (Direct Cost: ¥400,000、Indirect Cost: ¥120,000); Fiscal Year 2023: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000); Fiscal Year 2022: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000); Fiscal Year 2021: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000)
• Keywords: 共鳴非弾性X線散乱 / 交替磁性体 / 強相関電子系 / 第一原理計算 / 近藤効果 / スピントロニクス / 超伝導 / 遷移金属酸化物 / 動的平均場理論 / 素励起

Outline of Research at the Start

近年、共鳴非弾性X線散乱では実験の超高分解能化が進み、強相関物質を調べるプローブとして注目されている。しかし、データ解析には従来のクラスタ模型が変わらず用いられているため、超高分解能スペクトルが含むはずの伝導現象や素励起現象の情報を抽出できず、得られる知見は高分解能化に見合っているとは言えない。本研究では、密度汎関数理論と動的平均場理論に基づく理論枠組を軌道・バンド自由度と素励起間相互作用を扱えるように拡張することで、超高分解能RIXSから強相関物質の伝導現象を解明し、新奇素励起を探知できる新しい解析手法を構築し、強相関物性の問題（超伝導Ni酸化物、エキシトン凝縮、近藤転移）に取り組む。

Outline of Annual Research Achievements

ボーズ粒子型の動的平均場理論の計算コードを多軌道系に対応する形で拡張し、強相関励起子凝縮系の共鳴非弾性X線散乱(RIXS)の解析を実施した。ペロブスカイトコバルト酸化物における励起子相とスピン秩序相の予備計算において、2相のスペクトルの定性的な変化を確認した。昨年度までに整備した密度汎関数理論(DFT)と動的平均場理論(DMFT)に基づくX線分光スペクトルの計算パッケージを用いて、最近理論的に提案された交替磁性体のX線磁気二色性(XMCD)に関する理論予言を行った。この理論予言は、交替磁性体の候補物質alpha MnTeに対して英国のDiamond Light Source行われた実験で実証され、その結果は Physical Review Letters誌に発表した。また、別の交替磁性体の候補物質であるRuO2のXMCDの計算予言をPhysical Reivew B誌に発表した。さらに、MCD-RIXSの理論計算を進め、交替磁性体に特有の磁気励起がRIXSによって観測可能であることを明らかにした。昨年度までに整備したf電子系のスペクトル計算環境を活用し、ウラン化合物UGa2とUB2の内殻スペクトル解析を行い、DFT+DMFT法と硬X線分光（HAXPES）実験と組み合わせたウラン価数の決定方法を提案した。この研究により、HAXPESとRIXSの実験から見積もられるウランの価数が一見異なる値となる問題を解決した。

Current Status of Research Progress

1: Research has progressed more than it was originally planned.

Reason

予定よりも早く、ボーズ粒子型の動的平均場理論（DMFT）の計算コードを拡張することに成功し、励起子凝縮を示す可能性のあるコバルト酸化物を想定した共鳴非弾性X線散乱（RIXS）スペクトルの計算が可能となった。さらに、前年度に整備した密度汎関数理論（DFT）とDMFTを組み合わせたスペクトル計算コードを活用することで、新しい磁性体「交替磁性体」のX線分光に基づく同定方法を確立できた。さらに、DFT+DMFT法を活用して、ウラン化合物のX線光電子分光（XPS）、X線吸収スペクトル（XAS）及びRIXSの実験データを包括的に説明した研究成果をプレプリントとして公開した。

Strategy for Future Research Activity

ボーズ粒子型の動的平均場理論を用いたRIXSスペクトルの計算方法をまとめた論文を出版する予定である。また、今年度見出したRIXSを用いた交替磁性体の同定・評価方法を実験家と協力して検証したい。

Research Products

• [Int'l Joint Research] TU Wien(オーストリア)
• [Int'l Joint Research] Masaryk University(チェコ)
• [Int'l Joint Research] University of Hamburg/Deutsches Elektronen-Synchrotron DESY/Christian-Albrechts-University zu Kiel(ドイツ)
• [Int'l Joint Research] Utrecht University(オランダ)
• [Int'l Joint Research] Temple University(米国)
• [Int'l Joint Research]
• [Journal Article] X-ray magnetic circular dichroism in RuO2 (2024)
  • Author(s): Hariki A.、Takahashi Y.、Kune? J.
  • Journal Title: Physical Review B Volume: 109 Issue: 9 Pages: 094413-094413
  • DOI: 10.1103/physrevb.109.094413
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] High-Pressure Synthesis of a Novel Quadruple Perovskite Oxide AgCu₃Cr₄O₁₂ (2023)
  • Author(s): Kato Yuta、Furo Mizuki、Yamaguchi Tatsuya、Hariki Atsushi、Yamada Ikuya
  • Journal Title: MATERIALS TRANSACTIONS Volume: 64 Issue: 9 Pages: 2088-2092
  • DOI: 10.2320/matertrans.MT-MG2022016
  • ISSN: 1345-9678, 1347-5320
  • Year and Date: 2023-09-01
  • Peer Reviewed
• [Journal Article] Electronic structure of Electronic structure of ACu3Co4O12 ( A = Y, La, Bi): Synthesis, characterization, core-level spectroscopies, high-pressure application, and ab initio calculation (2023)
  • Author(s): Kato Yuta、Huang Meng-Jie、Kasebayashi Keito、Kawakami Takateru、Yamaguchi Tatsuya、Buck Jens、Wang Ru-Pan、Kall?ne Matthias、Rossnagel Kai、Nagel Peter、Schuppler Stefan、Takahashi Yoshihiro、Odake Takao、Kawaguchi Shogo、Yamada Ikuya、Hariki Atsushi
  • Journal Title: Physical Review Materials Volume: 7 Issue: 7 Pages: 073401-073401
  • DOI: 10.1103/physrevmaterials.7.073401
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Observation of temperature-dependent Fermi surface evolution at the valence transition of YbInCu4 (2023)
  • Author(s): Anzai Hiroaki、Hariki Atsushi、Sato Hitoshi、Arita Masashi、Zhuang Tao、Hiraoka Koichi
  • Journal Title: Physical Review B Volume: 108 Issue: 7 Pages: 075116-075116
  • DOI: 10.1103/physrevb.108.075116
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Modulation-doping a correlated electron insulator (2023)
  • Author(s): Mondal Debasish、Mahapatra Smruti Rekha、Derrico Abigail M.、Rai Rajeev Kumar、Paudel Jay R.、Schlueter Christoph、Gloskovskii Andrei、Banerjee Rajdeep、Hariki Atsushi、DeGroot Frank M. F.、Sarma D. D.、Narayan Awadhesh、Nukala Pavan、Gray Alexander X.、Aetukuri Naga Phani B.
  • Journal Title: Nature Communications Volume: 14 Issue: 1 Pages: 6210-6210
  • DOI: 10.1038/s41467-023-41816-3
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Hidden covalent insulator and spin excitations in SrRu2O6 (2023)
  • Author(s): Csontosova Diana、Chaloupka Jiri、Shinaoka Hiroshi、Hariki Atsushi、Kunes Jan
  • Journal Title: Physical Review B Volume: 108 Issue: 19 Pages: 195137-195137
  • DOI: 10.1103/physrevb.108.195137
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Single- and Multimagnon Dynamics in Antiferromagnetic α-Fe2O3 Thin Films (2023)
  • Author(s): Li Jiemin、Gu Yanhong、Takahashi Yoshihiro、Higashi Keisuke、Kim Taehun、Cheng Yang、Yang Fengyuan、Kune? Jan、Pelliciari Jonathan、Hariki Atsushi、Bisogni Valentina
  • Journal Title: Physical Review X Volume: 13 Issue: 1
  • DOI: 10.1103/physrevx.13.011012
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Charge-transfer effect in Fe 2p core-level x-ray photoemission spectra of trivalent Fe oxides: LDA+DMFT study (2022)
  • Author(s): Higashi Keisuke、Yamaguchi Tatsuya、Takahashi Yoshihiro、Hariki Atsushi
  • Journal Title: Journal of Physics: Condensed Matter Volume: 34 Issue: 37 Pages: 375602-375602
  • DOI: 10.1088/1361-648x/ac7f18
  • Peer Reviewed
• [Journal Article] Kondo quasiparticle dynamics observed by resonant inelastic x-ray scattering (2022)
  • Author(s): Rahn M. C.、Kummer K.、Hariki A.、Ahn K.-H.、Kune? J.、Amorese A.、Denlinger J. D.、Lu D.-H.、Hashimoto M.、Rienks E.、Valvidares M.、Haslbeck F.、Byler D. D.、McClellan K. J.、Bauer E. D.、Zhu J. X.、Booth C. H.、Christianson A. D.、Lawrence J. M.、Ronning F.、Janoschek M.
  • Journal Title: Nature Communications Volume: 13 Issue: 1
  • DOI: 10.1038/s41467-022-33468-6
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Satellites in the Ti 1s core level spectra of SrTiO3 and TiO2 (2022)
  • Author(s): Hariki Atsushi、Higashi Keisuke、Yamaguchi Tatsuya、Li Jiebin、Kalha Curran、Mascheck Manfred、Eriksson Susanna K.、Wiell Tomas、de Groot Frank M. F.、Regoutz Anna
  • Journal Title: Physical Review B Volume: 106 Issue: 20
  • DOI: 10.1103/physrevb.106.205138
  • Peer Reviewed
• [Journal Article] CaCu3Ru4O12: A High Kondo-Temperature Transition Metal Oxide (2022)
  • Author(s): D. Takegami, C. Kuo, K. Kasebayashi, J. Kim, C. Chang, C. Liu, C. Wu, D. Kasinathan, S. Altendorf, K. Hoefer, F. Meneghin, A. Marino, Y. Liao, K. Tsuei, C. Chen, K. Ko, A. Gunther, S. Ebbinghaus, J. Seo, D. Lee, G. Ryu, A. Komarek, S. Sugano, Y. Shimakawa, A. Tanaka, T. Mizokawa, J. Kune, L. Tjeng, and A. Hariki
  • Journal Title: Physical Review X Volume: 12 Issue: 1 Pages: 0110171-12
  • DOI: 10.1103/physrevx.12.011017
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Core-Level X-Ray Spectroscopy of Infinite-Layer Nickelate: LDA+DMFT study (2021)
  • Author(s): Higashi Keisuke、Winder Mathias、Kunes Jan、Hariki Atsushi
  • Journal Title: Physical Review X Volume: 11 Issue: 4 Pages: 041009-041009
  • DOI: 10.1103/physrevx.11.041009
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Valence skipping, internal doping, and site-selective Mott transition in PbCoO3 under pressure (2021)
  • Author(s): Hariki Atsushi、Ahn Kyo-Hoon、Kunes Jan
  • Journal Title: Physical Review B Volume: 104 Issue: 23 Pages: 235101-235101
  • DOI: 10.1103/physrevb.104.235101
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Presentation] LDA+DMFT approach to core-level spectroscopy in 4f and 5f intermetallic compounds (2023)
  • Author(s): Atsushi Hariki
  • Organizer: International Workshop on the Dual Nature of f-Electrons 2023
  • Int'l Joint Research / Invited
• [Presentation] LDA+DMFT approach to resonant inelastic x-ray scattering in correlated materials (2023)
  • Author(s): Atsushi Hariki
  • Organizer: RIXS / RXES workshop 2023
  • Int'l Joint Research / Invited
• [Presentation] X-ray spectroscpies in altermagnetic α-MnTe (2023)
  • Author(s): Atsushi Hariki
  • Organizer: Trends in the Theory of Quantum Materials 2023
  • Int'l Joint Research
• [Presentation] Valence skipping, internal doping and structural transition in PbCoO3 and PbCrO3 under pressure (2023)
  • Author(s): Atsushi Hariki
  • Organizer: Functional Transition Metal Oxides by Design
  • Int'l Joint Research / Invited
• [Presentation] Kondo physics in CaCu3Ru4O12: LDA+DMFT and X-ray photoemission spectroscopy study (2022)
  • Author(s): Atsushi Hariki, Keito Kasebayashi, and Jan Kunes
  • Organizer: The 32nd Annual Meeting of MRS-J
  • Invited
• [Presentation] Dynamics of spin, orbital and charge excitations in strongly correlated materials revealed by resonant inelastic x-ray scattering (2022)
  • Author(s): Atsushi Hariki
  • Organizer: The 6th QST International Symposium
  • Int'l Joint Research / Invited
• [Presentation] LDA+DMFT approach to resonant inelastic x-ray scattering in correlated materials (2022)
  • Author(s): 播木敦
  • Organizer: 次世代放射光で切り拓く軟X線科学 日本放射光学会 第14回若手研究会
  • Invited
• [Presentation] CaCu3Ru4O12: A High Kondo-Temperature Transition Metal Oxide (2022)
  • Author(s): Atsushi Hariki
  • Organizer: International Workshop Computational Approaches to Magnetic Systems
  • Int'l Joint Research / Invited
• [Presentation] CaCu3Ru4O12: A High Kondo-Temperature Transition Metal Oxid (2022)
  • Author(s): Atsushi Hariki
  • Organizer: International Workshop on the Dual Nature of f-Electrons 2022
  • Int'l Joint Research / Invited
• [Presentation] LDA+DMFT approach to core-level x-ray spectroscopies in correlated electron systems (2022)
  • Author(s): Atsushi Hariki, Keisuke Higashi, Tatsuya Yamaguchi, Winder Mathias, Takayuki Uozumi, and Jan Kunes
  • Organizer: The 9th International Conference on Hard X-ray Photoelectron Spectroscopy
  • Int'l Joint Research / Invited
• [Presentation] CaCu3Ru4O12: A High Kondo-Temperature Transition Metal Oxide (2022)
  • Author(s): Atsushi Hariki, Keito Kasebayashi, and Jan Kunes
  • Organizer: International Conference on Strongly Correlated Electron Systems (SCES) 2022
  • Int'l Joint Research
• [Presentation] Fe2O3のFe L3端高分解能共鳴非弾性X線散乱 (2022)
  • Author(s): 髙橋良拓, Li Jiemin, 東啓介, 魚住孝幸, Jan Kunes, Gu Yanhong, Pelliciari Jonathan, Valentina Bisogni, 播木敦
  • Organizer: 日本物理学会第77回年次大会
• [Presentation] 内殻X線分光を用いた超伝導層状ニッケル酸化物の電子状態の研究 (2022)
  • Author(s): 東啓介, Mathias Winder, Jan Kunes, 播木敦
  • Organizer: 日本物理学会第77回年次大会
• [Presentation] Aサイト秩序ペロブスカイト酸化物ACu3Fe4O12の金属絶縁体転移 (2022)
  • Author(s): 山口達也, Kyo-Hoon, Mathias Mathias, Jan Kunes, 播木敦
  • Organizer: 日本物理学会第77回年次大会
• [Presentation] 四重ペロブスカイト酸化物CaCu3Ru4O12の近藤現象 (2022)
  • Author(s): 加瀬林啓人, Daisuke Takegami, et al.
  • Organizer: 日本物理学会第77回年次大会
• [Presentation] LDA+DMFT approach to resonant inelastic x-ray scattering in correlated materials (2021)
  • Author(s): Atsushi Hariki, Mathias Winder, Takayuki Uozumi, and Jan Kunes
  • Organizer: Global Summit on Condensed Matter Physics (CONMAT2021)
  • Invited
• [Presentation] Core-level x-ray spectroscopy of infinite-layer nickelate: LDA+DMFT study (2021)
  • Author(s): Atsushi Hariki, Keisuke Higashi, Mathias Winder, and Jan Kunes
  • Organizer: The 11th New Generation in Strongly Correlated Electron Systems
• [Presentation] Core-level x-ray spectroscopy of infinite-layer nickelate: LDA+DMFT study (2021)
  • Author(s): Keisuke Higashi, Mathias Winder, Jan Kunes, and Atsushi Hariki
  • Organizer: International Conference on X-ray Absorption Fine Structure 2021
• [Presentation] Kondo physics in the A-site ordered perovskite CaCu3Ir4O12 and CaCu3Ru4O12 (2021)
  • Author(s): Keito Kasebayashi, Jan Kunes, and Atsushi Hariki
  • Organizer: The 11th New Generation in Strongly Correlated Electron Systems