Control of the Mott transition by uniaxial pressure

2013 Fiscal Year Final Research Report

• Project/Area Number: 25610095
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Single-year Grants
• Research Field: Condensed matter physics II
• Research Institution: Kyoto University
• Principal Investigator: MAENO Yoshiteru 京都大学, 理学(系)研究科(研究院), 教授 (80181600)
• Co-Investigator(Kenkyū-buntansha): YONEZAWA Shingo 京都大学, 大学院・理学研究科, 助教 (30523584) ; NAKAMURA Fumihiko 久留米工業大学, 工学部, 教授 (40231477)
• Project Period (FY): 2013-04-01 – 2014-03-31
• Keywords: 一軸性圧力 / モット転移 / ルテニウム酸化物 / スピン三重項超伝導 / ピエゾ素子

Research Abstract

Application of pressure is known to induce a metallic state from an insulator or to enhance the transition temperature of a superconductor. In this project, we focus on the application of uniaxial pressure in order to amplify the effect or extract underlining mechanisms of an insulator-metal transition and exotic superconductivity. We improve the pressure apparatus for low-temperature experiments on brittle oxide crystals, as well as introduce a new apparatus capable of application of both compressional and tensile strain. Using layered ruthenium oxides, we found a strong in-plane anisotropy of the transition from a Mott insulator to a ferromagnetic metal. We also found that the superconducting transition of the ruthenium oxide Sr2RuO4 is enhanced by both compressional and tensile strain, thereby confirming the unusual behavior expected in a spin-triplet superconductor with aligned Cooper-pair angular momenta. These results demonstrate the usefulness of uniaxial pressure experiments.

Research Products

• [Journal Article] Strong Increase of T c of Sr2RuO4 under both Tensile and Compressive Strain (2014)
  • Author(s): C. W. Hicks, D. O. Brodsky, E. A. Yelland, A. S. Gibbs, J. A. N. Bruin, M. E. Barber, S. D. Edkins, K. Nishimura, S. Yonezawa, Y. Maeno, A. P. Mackenzie
  • Journal Title: Science Volume: 344 Pages: 283-1-4
  • DOI: 10.1126/science.1248292
  • Peer Reviewed
• [Journal Article] Anisotropic Uniaxial Pressure Response of the Mott Insulator Ca2RuO4 (2013)
  • Author(s): Haruka Taniguchi, Keigo Nishimura, Ryo Ishikawa, Shingo Yonezawa, Swee K. Goh, Fumihiko Nakamura, and Yoshiteru Maeno
  • Journal Title: Physical Review Volume: B88 Pages: 205111-1-6
  • DOI: 10.1103/PhysRevB.88.205111
  • Peer Reviewed
• [Presentation] 一軸性圧力によるモット絶縁体Ca2RuO4の金属化磁性と面内異方性 (2013)
  • Author(s): 谷口晴香, 西村佳悟, 米澤進吾, 中村文彦, 近藤隆祐, 野上由夫, 前野悦輝
  • Organizer: 日本物理学会2013秋季大会(徳島大学)
  • Place of Presentation: 徳島市
  • Year and Date: 2013-09-28
• [Remarks] モット絶縁体Ca2RuO4への面内一軸性圧力効果の異方性(京大固体量子物性研究室)
  • URL: http://www.ss.scphys.kyoto-u.ac.jp/contents/research/topics/2013/topic201311-01.html