Control of electronic state of correlated topological quantum systems utilizing superstructure

• Project/Area Number: 26610097
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Condensed matter physics II
• Research Institution: The University of Tokyo
• Principal Investigator: Fujioka Jun 東京大学, 工学(系)研究科(研究院), 講師 (80609488)
• Project Period (FY): 2014-04-01 – 2016-03-31
• Project Status: Completed (Fiscal Year 2015)
• Budget Amount: ¥3,770,000 (Direct Cost: ¥2,900,000、Indirect Cost: ¥870,000); Fiscal Year 2015: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000); Fiscal Year 2014: ¥2,210,000 (Direct Cost: ¥1,700,000、Indirect Cost: ¥510,000)
• Keywords: 物性実験 / 強相関電子系 / 強相関エレクトロニクス / 低温物性

Outline of Final Research Achievements

We have studied the new topological electronic phase in pyrochlore iridates, which is one of the correlated topological semimetals. As a results, we found that a new topological Mott insulating state so called as Weyl Mott insulator can be realized on the verge of band-width controlled Mott transition. Moreover, it turned out that the electrical conductivity of edge state emerging at magnetic domain walls is reduced when the bandwidth is tuned away from Mott transition.

Research Products

• [Int'l Joint Research] Stanford University(米国)
• [Journal Article] Magnetic field-induced insulator-semimetal transition in a pyrochlore Nd2Ir2O7 (2015)
  • Author(s): K. Ueda, J. Fujioka, B.-J. Yang, J. Shiogai, A. Tsukazaki, S. Nakamura, S. Awaji, N. Nagaosa, and Y. Tokura
  • Journal Title: Physical Review Letters Volume: 115 Issue: 5 Pages: 056402-056402
  • DOI: 10.1103/physrevlett.115.056402
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Pressure and magnetic eld effects on metal-insulator transitions of bulk and domain wall states in pyrochlore iridates (2015)
  • Author(s): K. Ueda, J. Fujioka, C. Terakura, and Y. Tokura
  • Journal Title: Physical Review B Volume: 92 Issue: 12 Pages: 121110-121110
  • DOI: 10.1103/physrevb.92.121110
  • Peer Reviewed
• [Journal Article] Mobile metallic domain walls in an all-in-all-out magnetic insulator (2015)
  • Author(s): Eric Yue Ma, Yong-Tao Cui, Kentaro Ueda, Shujie Tang, Kai Chen, Nobumichi Tamura, Phillip M. Wu, Jun Fujioka, Yoshinori Tokura, and Zhi-Xun Shen
  • Journal Title: Science Volume: 350 Issue: 6260 Pages: 538-541
  • DOI: 10.1126/science.aac8289
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Perovskite LaRhO3 as a p-type active layer in oxide photovoltaics (2015)
  • Author(s): Masao Nakamura, Yoshiharu Krockenberger, Jun Fujioka, Masashi Kawasaki, and Yoshinori Tokura
  • Journal Title: APPLIED PHYSICS LETTERS Volume: 106
  • Peer Reviewed
• [Journal Article] Multi-spin-state dynamics during insulator-metal crossover in LaCoO3 (2014)
  • Author(s): A. Doi, J. Fujioka, T. Fukuda, S. Tsutsui, D. Okuyama, Y. Taguchi, T. Arima, A. Q. R. Baron, and Y. Tokura
  • Journal Title: PHYSICAL REVIEW B Volume: 90
  • Peer Reviewed
• [Presentation] スピン状態転移のダイナミクス 赤外・X線散乱の立場から (2014)
  • Author(s): 藤岡 淳
  • Organizer: 日本物理学会 領域８シンポジウム コバルト酸化物のスピンクロスオーバー現象の新展開
  • Place of Presentation: 中部大学、愛知県
  • Year and Date: 2014-09-07 – 2014-09-10
  • Invited
• [Presentation] Metal-insulator transition in Pyrochlore-type iridates with anomalous magnetic domain-wall conductance (2014)
  • Author(s): Jun Fujioka
  • Organizer: International Conference on Highly Frustrated Magnetisim
  • Place of Presentation: Cambridge, United Kingdom
  • Year and Date: 2014-07-06 – 2014-07-11
  • Invited