Ultrasound measurements under megagauss fields

• Project/Area Number: 20K14403
• 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: The University of Tokyo
• Principal Investigator: Nomura Toshihiro 東京大学, 物性研究所, 助教 (20845987)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Project Status: Completed (Fiscal Year 2022)
• Budget Amount: ¥4,160,000 (Direct Cost: ¥3,200,000、Indirect Cost: ¥960,000); Fiscal Year 2022: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000); Fiscal Year 2021: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000); Fiscal Year 2020: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000)
• Keywords: 超強磁場 / 超音波 / 酸素 / 非相反 / 量子スピン / 液体酸素 / 磁場誘起相転移 / 強磁場 / 相転移

Outline of Research at the Start

超音波測定は構造相転移や秩序パラメタの対称性を議論する上で強力な手法であり、金属・絶縁体を問わず多くの物質群に適用できる魅力的な測定プローブである。しかしながら、100テスラを超えるような超強磁場下では実験的制約が多く、これまで超音波と組み合わせた測定は不可能と考えられてきた。本申請ではCW法（連続励起法）と位相検波法を組み合わせた高速な超音波計測技術を提案し、超磁場領域における格子物性測定に挑戦する。

Outline of Final Research Achievements

A new method for measuring ultrasonic sound velocity of materials has been successfully developed in combination with the single-turn coil method, a destructive magnetic field generation technique. By applying the developed method to liquid oxygen, quantum spin systems, and heavy fermion systems, we succeeded in obtaining information on the change of elastic constants of materials in the ultrahigh magnetic field-induced phase transitions. In particular, for liquid oxygen, we obtained results suggesting a precursor of the liquid-liquid phase transition induced by a magnetic field. In addition, a giant elastic anomaly in the 1/2 plateau phase was observed in the two-dimensional quantum spin system SrCu2(BO3)2. The developed measurement technique is expected to be a powerful tool to explore ultrahigh magnetic field physics in the future.

Academic Significance and Societal Importance of the Research Achievements

これまで磁場中物性に関する複数の研究がノーベル賞の対象になっていることからわかるように、強磁場下における物質の性質は多彩かつ複雑であり、未だに固体物理のフロンティアにある。超強磁場下における物性測定には多くの制限があり、これまで格子物性に関する情報はほとんど報告例が無かった。本研究では新たに音速（弾性定数）に関する情報を得る計測手法を開発し、物性測定に応用した。本研究で開発した手法は他の物質群にも適用可能であり、超強磁場下での新たな物性を探索する上で強力な手法となる。

Research Products

• [Int'l Joint Research] HLD-HZDR(ドイツ)
• [Int'l Joint Research] Univ. of Amsterdam(オランダ)
• [Int'l Joint Research] EPFL(スイス)
• [Int'l Joint Research] CNRS/CEA(フランス)
• [Journal Article] Quantum oscillations in the centrosymmetric skyrmion-hosting magnet GdRu2Si2 (2023)
  • Author(s): N. Matsuyama, T. Nomura, S. Imajo, T. Nomoto, R. Arita, K. Sudo, M. Kimata, N. D. Khanh, R. Takagi, Y. Tokura, S. Seki, K. Kindo, Y. Kohama
  • Journal Title: Physical Review B Volume: 107 Issue: 10 Pages: 104421-104421
  • DOI: 10.1103/physrevb.107.104421
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] High-mobility two-dimensional carriers from surface Fermi arcs in magnetic Weyl semimetal films (2022)
  • Author(s): Kaneta-Takada Shingo、Wakabayashi Yuki K.、Krockenberger Yoshiharu、Nomura Toshihiro、Kohama Yoshimitsu、Nikolaev Sergey A.、Das Hena、Irie Hiroshi、Takiguchi Kosuke、Ohya Shinobu、Tanaka Masaaki、Taniyasu Yoshitaka、Yamamoto Hideki
  • Journal Title: npj Quantum Materials Volume: 7 Issue: 1 Pages: 1-12
  • DOI: 10.1038/s41535-022-00511-0
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Emergent anisotropy in the Fulde-Ferrell-Larkin-Ovchinnikov state (2022)
  • Author(s): Imajo Shusaku、Nomura Toshihiro、Kohama Yoshimitsu、Kindo Koichi
  • Journal Title: Nature Communications Volume: 13 Issue: 1 Pages: 5590-5590
  • DOI: 10.1038/s41467-022-33354-1
  • Peer Reviewed / Open Access
• [Journal Article] Magnetically Hidden State on the Ground Floor of the Magnetic Devil’s Staircase (2022)
  • Author(s): Imajo S.、Matsuyama N.、Nomura T.、Kihara T.、Nakamura S.、Marcenat C.、Klein T.、Seyfarth G.、Zhong C.、Kageyama H.、Kindo K.、Momoi T.、Kohama Y.
  • Journal Title: Physical Review Letters Volume: 129 Issue: 14 Pages: 147201-147201
  • DOI: 10.1103/physrevlett.129.147201
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] The Shastry-Sutherland Compound SrCu2(BO3)2 Studied up to the Saturation Magnetic Field (2022)
  • Author(s): T. Nomura, P. Corboz, A. Miyata, S. Zherlitsyn, Y. Ishii, Y. Kohama, Y. H. Matsuda, A. Ikeda, C. Zhong, H. Kageyama, F. Mila
  • Journal Title: arxiv Volume: 2209 Pages: 07652-07652
  • Open Access / Int'l Joint Research
• [Journal Article] Ferroelectric Transition of a Chiral Molecular Crystal BINOL2DMSO (2022)
  • Author(s): Nomura Toshihiro、Yajima Takeshi、Yang Zhuo、Kurihara Ryosuke、Ishii Yuto、Tokunaga Masashi、Matsuda Yasuhiro H.、Kohama Yoshimitsu、Kimura Kenta、Kimura Tsuyoshi
  • Journal Title: Journal of the Physical Society of Japan Volume: 91 Issue: 6 Pages: 064702-064702
  • DOI: 10.7566/jpsj.91.064702
  • Peer Reviewed
• [Journal Article] Solid and Liquid Oxygen under Ultrahigh Magnetic Fields (2022)
  • Author(s): Nomura Toshihiro、Matsuda Yasuhiro H.、Kobayashi Tatsuo C.
  • Journal Title: Oxygen Volume: 2 Issue: 2 Pages: 152-163
  • DOI: 10.3390/oxygen2020013
  • Peer Reviewed / Open Access
• [Journal Article] Time-resolved measurements in pulsed magnetic fields (2022)
  • Author(s): Kohama Yoshimitsu、Nomura Toshihiro、Zherlitsyn Sergei、Ihara Yoshihiko
  • Journal Title: Journal of Applied Physics Volume: 132 Issue: 7 Pages: 070903-070903
  • DOI: 10.1063/5.0093985
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Physical properties of liquid oxygen under ultrahigh magnetic fields (2021)
  • Author(s): Nomura T.、Ikeda A.、Gen M.、Matsuo A.、Kindo K.、Kohama Y.、Matsuda Y. H.、Zherlitsyn S.、Wosnitza J.、Tsuda H.、Kobayashi T. C.
  • Journal Title: Physical Review B Volume: 104 Issue: 22 Pages: 224423-224423
  • DOI: 10.1103/physrevb.104.224423
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Ultrasound measurement technique for the single-turn-coil magnets (2021)
  • Author(s): Nomura T.、Hauspurg A.、Gorbunov D. I.、Miyata A.、Schulze E.、Zvyagin S. A.、Tsurkan V.、Matsuda Y. H.、Kohama Y.、Zherlitsyn S.
  • Journal Title: Review of Scientific Instruments Volume: 92 Issue: 6 Pages: 063902-063902
  • DOI: 10.1063/5.0045209
  • Peer Reviewed / Int'l Joint Research
• [Presentation] カイラル強磁性体Co9Zn9Mn2におけるフォノンの非相反物性 (2023)
  • Author(s): 野村肇宏
  • Organizer: 日本物理学会
• [Presentation] 酸素の超強磁場物性に関する研究 (2023)
  • Author(s): 野村肇宏
  • Organizer: 日本物理学会
• [Presentation] 直交ダイマー系物質SrCu2(BO3)2の飽和磁場までの格子物性 (2022)
  • Author(s): 野村肇宏
  • Organizer: 日本物理学会
• [Presentation] Acoustic properties of SrCu2(BO3)2 up to the saturation magnetic fields (2022)
  • Author(s): T. Nomura
  • Organizer: HFM2022
  • Int'l Joint Research
• [Presentation] Quest for a Magnetic-field-induced Liquid-liquid Transition of Oxygen by Ultrasound Measurements in Megagauss Region (2021)
  • Author(s): Toshihiro Nomura
  • Organizer: 1st Asia-Pacific Conference on Condensed Matter Physics 2021(AC2MP2021)
  • Int'l Joint Research / Invited
• [Book] 固体物理 (2023)
  • Author(s): 野村肇宏
  • Publisher: アグネ技術センター
• [Remarks] 「磁気的な悪魔の階段」の手前に「隠れた状態」を発見
  • URL: https://www.issp.u-tokyo.ac.jp/maincontents/news2.html?pid=16660
• [Remarks] 新しいカイラル有機強誘電体の発見
  • URL: https://www.issp.u-tokyo.ac.jp/maincontents/news2.html?pid=15824
• [Remarks] 強磁場中でも生き残る空間的に変調した超伝導を有機物中で発見
  • URL: https://www.issp.u-tokyo.ac.jp/maincontents/news2.html?pid=16626
• [Remarks] 室温付近まで維持される音波の非相反物性の発見
  • URL: https://www.issp.u-tokyo.ac.jp/maincontents/news2.html?pid=18369