Signal transfer by stochastic resonance in cooperation with proton-fluctuation and enhancement of charge-transfer in molecular materials as biological model system

• Project/Area Number: 18K18725
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 13:Condensed matter physics and related fields
• Research Institution: Tohoku University
• Principal Investigator: SASAKI TAKAHIKO 東北大学, 金属材料研究所, 教授 (20241565)
• Project Period (FY): 2018-06-29 – 2021-03-31
• Project Status: Completed (Fiscal Year 2020)
• Budget Amount: ¥6,370,000 (Direct Cost: ¥4,900,000、Indirect Cost: ¥1,470,000); Fiscal Year 2020: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000); Fiscal Year 2019: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000); Fiscal Year 2018: ¥2,470,000 (Direct Cost: ¥1,900,000、Indirect Cost: ¥570,000)
• Keywords: ノイズスペクトロスコピー / 分子性物質 / プロトン / 分子性有機導体 / ノイズ / プロトン運動

Outline of Final Research Achievements

In this study, we have developed a precise method for detecting conductance noise in molecular materials with strongly correlated electrons, in which pi-electron-based charge dynamics is significantly coupled with proton dynamics. We succeeded in measuring the conductance noise generated by pi-electrons coupling with proton and ethylene group dynamics. The Lorentzian-type noise spectrum due to the conductance fluctuation of a clear two-level state was observed to be superimposed on the 1/f type noise spectrum. The electric polarization state with a polar nano-region was clarified by noise spectroscopy.

Academic Significance and Societal Importance of the Research Achievements

今回の研究によるノイズ観測手法の確立およびパイ電子系ノイズ発生と電子状態の相関解明・発見は，ノイズスペクトロスコピーが電子的な強誘電性を生み出す分子性物質の物性物理解明に有効であることを明らかにした．さらに，生体系電子機能性の解明と機能模倣を目指す研究を実施する上で，ノイズスペクトロスコピーは，プロトン運動や構造ゆらぎと連動する電子伝達を調査するための高感度な観測ツールとなることを示すことができた．

Research Products

• [Int'l Joint Research] Goethe University Frankfurt(ドイツ)
• [Int'l Joint Research] Institute of Physics, Goethe-University(ドイツ)
• [Int'l Joint Research] National Science Foundation(米国)
• [Journal Article] Formation of nanoscale polarized clusters as precursors of electronic ferroelectricity probed by conductance noise spectroscopy (2020)
  • Author(s): Jens Mueller, Satoshi Iguchi, Hiromi Taniguchi and Takahiko Sasaki
  • Journal Title: Phys. Rev. B Volume: 102 Issue: 10
  • DOI: 10.1103/physrevb.102.100103
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Presentation] 分子性有機導体k-(d8-BEDT-TTF)2Cu[N(CN)2]Brのエックス線照射効果 (2021)
  • Author(s): 佐々木孝彦, 佐藤直道, 米山直樹
  • Organizer: 日本物理学会第76回年次大会
• [Presentation] Nanoscale polarized clusters in a molecular dimer-Mott insulator as precursors of electronic ferroelectricity probed by conductance noise spectroscopy (2020)
  • Author(s): Takahiko Sasaki
  • Organizer: Quantum Liquid Crystal meeting 2020
  • Invited
• [Presentation] 傾斜エックス線照射した分子性有機導体 k-(BEDT-TTF)2Xの赤外分光 (2020)
  • Author(s): 佐々木孝彦, 佐藤直道, 古川哲也, 杉浦栞理, 井口敏, 米山直樹, L. Kang, 赤木和人, 池本夕佳, 森脇太郎
  • Organizer: 日本物理学会2020年秋季大会
• [Presentation] Low-frequency Charge Carrier Dynamics in the Mott and Charge-Ordered Insulating Phases of Quasi-2D Mplecular Conductors (BEDT-TTF)2X (2019)
  • Author(s): J. Mueller, T. Thomas, B. Hartmann, H. Schubert, S. Iguchi, K. Hashimoto, T. Sasaki, J. A. Schlueter
  • Organizer: 13th International Symposium on Crystalline Organic Metals, Superconductors and Magnets (ISCOM2019)
  • Int'l Joint Research
• [Presentation] Charge Carrier Dynamics in q-(BEDT-TTF)2RbZn(SCN)4 studied by Fluctuation Spectroscopy (2019)
  • Author(s): T. Thomas, H. Sun, K. Hashimoto, T. Sasaki, H. Yamamoto, J. Mueller
  • Organizer: 13th International Symposium on Crystalline Organic Metals, Superconductors and Magnets (ISCOM2019)
  • Int'l Joint Research
• [Presentation] Quenched disorder effect on the charge-glass forming ability in the charge ordered molecular compound q-(BEDT-TTF)2RbZn(SCN)4 (2019)
  • Author(s): S. Ohkura, K. Hashimoto, R. Kobayashi, Y. Karakane, S. Iguchi, Y. Ikemoto, T. Moriwaki, M. Suda, H. Yamamoto, T. Sasaki
  • Organizer: 13th International Symposium on Crystalline Organic Metals, Superconductors and Magnets (ISCOM2019)
  • Int'l Joint Research
• [Presentation] BEDT-TTF分子系電荷秩序絶縁体の電荷ガラス形成能に与える乱れ効果 (2019)
  • Author(s): 佐々木孝彦, 大藏聖, 橋本顕一郎, 小林亮太, 唐金雄也, 池本夕佳, 森脇太郎, 須田理行, 山本浩史
  • Organizer: 日本物理学会第74回年次大会（2019年）
• [Presentation] 水素結合型モット絶縁体Cat-EDT系における量子常誘電・常磁性状態 (2019)
  • Author(s): 藤井桜子, 下澤雅明, 近藤潤, 杉井かおり, 山下穣, 上田顕, 森初果, 杉浦栞理, 寺嶋太一, 宇治進也, 橋本顕一郎, 井口敏, 佐々木孝彦
  • Organizer: 日本物理学会第74回年次大会（2019年）
• [Remarks] 東北大学金属材料研究所低温電子物性学研究部門HP
  • URL: http://cond-phys.imr.tohoku.ac.jp/
• [Remarks] 東北大学金属材料研究所低温電子物性学研究部門佐々木研究室
  • URL: http://cond-phys.imr.tohoku.ac.jp/