Angle-resolved photoemission study on Fermi surface of quantum well structures based on strongly correlated oxides

2009 Fiscal Year Self-evaluation Report

• Project/Area Number: 19684010
• Research Category: Grant-in-Aid for Young Scientists (A)
• Allocation Type: Single-year Grants
• Research Field: Condensed matter physics II
• Research Institution: The University of Tokyo
• Principal Investigator: KUMIGASHIRA Hiroshi The University of Tokyo, 大学院・工学系研究科, 准教授 (00345092)
• Project Period (FY): 2007 – 2010
• Keywords: 光電子分光 / 強相関エレクトロニクス / 表面・界面物性 / 強相関電子系 / 量子井戸 / 酸化物超構造 / 酸化物ヘテロ構造 / 酸化物薄膜

Research Abstract

銅酸化物の高温超伝導に代表される層状酸化物が示す特異物性は、低次元性と結び付いた強相関電子状態にその起源をもつ。層状酸化物の結晶構造を絶縁層(電荷供給層)で2次元的な伝導層を挟み込んだ構造をもつ自然量子井戸構造ととらえると、低次元強相関物性への最も直接的なアプローチとして、酸化物量子井戸構造を用いることで低次元電子状態を任意に制御し、その物性変化を調べるという研究に行き着く。つまり、この強相関酸化物量子井戸構造で発現する低次元電子状態を直接観測することは、低次元強相関酸化物の示す特異物性の機構解明に直接結び付く。そのため、本研究では、レーザー分子線エピタキシー法により原子レベルで構造を制御した「強相関酸化物量子井戸構造」を作製し、この強相関酸化物量子井戸構造を用いて新規な低次元電子状態をデザインする。そして、このフェルミ面トポロジーを高分解能角度分解光電子分光法により直接決定し、物性との相関関係を明らかにすることにより低次元強相関物性を明らかにすることを目的とする。

Research Products

• [Journal Article] Thickness dependent electronic structure of La0. 6Sr0. 4MnO3 layer in SrTiO3/La0. 6Sr0. 4MnO3/SrTiO3 heterostructures studied by hard x-ray photoemission spectroscopy (2009)
  • Author(s): K. Yoshimatsu, K. Horiba, H. Kumigashira, E. Ikenaga, M. Oshima
  • Journal Title: Appl. Phys. Lett. 94 Pages: 071901[1-3]
• [Journal Article] Yoshimatsu et al. Reply (2009)
  • Author(s): K. Yoshimatsu, R. Yasuhara, H. Kumigashira, M. Oshima
  • Journal Title: Phys. Rev. Lett. 102 Pages: 199704[1]
• [Journal Article] Pressure-induced change in the electronic structure of epitaxially strained La1-xSrxMnO3 thin films (2009)
  • Author(s): K. Horiba, A. Maniwa, A. Chikamatsu, K. Yoshimatsu, H. Kumigashira, H. Wadati, A. Fujimori, D. Nomoto, S. Ueda, H. Yoshikawa, E. Ikenaga, J.J. Kim, K. Kobayashi, M. Oshima
  • Journal Title: Phys. Rev. B 80 Pages: 132406[1-4]
• [Journal Article] Coherent and incoherent d band dispersions in SrVO3 (2009)
  • Author(s): M. Takizawa, M. Minohara, H. Kumigashira, D. Toyota, M. Oshima, H. Wadati, T. Yoshida, A. Fujimori, M. Lippmaa, M. Kawasaki, H. Koinuma, G. Sordi, M. Rozenberg
  • Journal Title: Phys. Rev. B 80 Pages: 235104[1-4]
• [Journal Article] In-situ Photoemission Study of Pr1-xCaxMnO3 Epitaxial Thin Films with Suppressed Charge Fluctuations (2008)
  • Author(s): H. Wadati, A. Maniwa, A. Chikamatsu, I. Ohkubo, H. Kumigashira, M. Oshima, A. Fujimori, M. Lippmaa, M. Kawasaki, H. Koinuma
  • Journal Title: Phys. Rev. Lett. 100 Pages: 026402[1-4]
• [Journal Article] Origin of metallic states at the heterointerface between the band insulators LaAlO3 and SrTiO3 (2008)
  • Author(s): K. Yoshimatsu, R. Yasuhara, H. Kumigashira, M. Oshima
  • Journal Title: Phys. Rev. Lett. 101 Pages: 026802[1-4]
• [Journal Article] Dimensional-Crossover-Driven Metal-Insulator Transition in SrVO3 Ultrathin Films
  • Author(s): K. Yoshimatsu, T. Okabe, H. Kumigashira, S. Okamato, S. Aizaki, A. Fujimori, M. Oshima
  • Journal Title: Phys. Rev. Lett. (in press)
• [Presentation] In-situ photoemission studies on oxide heterostructures (2009)
  • Author(s): Hiroshi KUMIGASHIRA
  • Organizer: 11-th International Conference on Electronic Spectroscopy and Structure (ICESS-11)
  • Place of Presentation: Nara, Japan
  • Year and Date: 2009-10-08
• [Presentation] In-situ Photoemission Studies on Oxide Heterostructures (2009)
  • Author(s): Hiroshi KUMIGASHIRA
  • Organizer: 2009 Villa Conference on Complex Oxide Heterostructures (VC-COH)
  • Place of Presentation: Ritz Carlton - St. Thomas, USVI
  • Year and Date: 2009-09-16
• [Presentation] その場放射光電子分光による強相関酸化物超構造の電子状態研究 (2009)
  • Author(s): 組頭広志
  • Organizer: 日本物理学会第64回年次大会
  • Place of Presentation: 立教大学
  • Year and Date: 2009-03-27
• [Presentation] Synchrotron radiation studies of oxide surfaces (2009)
  • Author(s): Hiroshi KUMIGASHIRA
  • Organizer: 6th International Workshop on 0xide Surfaces
  • Place of Presentation: Schladming, Austria
  • Year and Date: 2009-01-19
• [Presentation] Interfacial Electronic Structure of Perovskite Oxide ABO3/SrTiO3 Heterojunctions (2008)
  • Author(s): Hiroshi KUMIGASHIRA
  • Organizer: The IUMRS International Conference in Asia 2008
  • Place of Presentation: Nagoya Congress Center, Nagoya, Japan
  • Year and Date: 2008-12-12
• [Presentation] In-situ photoemission studies on oxide heterostructures (2008)
  • Author(s): 組頭広志
  • Organizer: 日本物理学会第63回年次大会
  • Place of Presentation: 近畿大学(東大阪)キャンパス
  • Year and Date: 2008-03-23