Theoretical study on topological quantum phenomena in topological semimetals

• Project/Area Number: 16H06861
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Single-year Grants
• Research Field: Mathematical physics/Fundamental condensed matter physics
• Research Institution: Nagoya University
• Principal Investigator: Kobayashi Shingo 名古屋大学, 工学研究科, 特任助教 (40779675)
• Project Period (FY): 2016-08-26 – 2018-03-31
• Project Status: Completed (Fiscal Year 2017)
• Budget Amount: ¥2,990,000 (Direct Cost: ¥2,300,000、Indirect Cost: ¥690,000); Fiscal Year 2017: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000); Fiscal Year 2016: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000)
• Keywords: トポロジカル半金属 / トポロジカル超伝導体 / ディラック半金属 / トポロジカル超伝導 / アンチペロブスカイト化合物 / スピン軌道相互作用 / トポロジカル物質 / 異方的超伝導体 / ラインノード半金属 / トポロジカル相転移 / 物性基礎論 / トポロジー

Outline of Final Research Achievements

Topological semimetals have recently attracted considerable theoretical and experimental interest since they exhibit anomalous electromagnetic response and topological superconductivity.
The first research outcome is to establish the general theory of crossing-line-node semimetals and propose candidate materials. This research may stimulate experimental search for topological materials.
The second research outcome is to clarify topological superconductivity in antiperovskite type Dirac semimetals and investigate a new topological phase with a higher winding number.

Research Products

• [Int'l Joint Research] サレルノ大学(イタリア)
• [Journal Article] Crossing-Line-Node Semimetals: General Theory and Application to Rare-Earth Trihydrides (2017)
  • Author(s): Shingo Kobayashi, Youichi Yamakawa, Ai Yamakage, Takumi Inohara, Yoshihiko Okamoto, and Yukio Tanaka
  • Journal Title: Physical Review B Volume: 95 Issue: 24
  • DOI: 10.1103/physrevb.95.245208
  • NAID: 120006337725
  • Peer Reviewed
• [Journal Article] Theoretical band structure of the superconducting antiperovskite oxide Sr3－xSnO (2017)
  • Author(s): A. Ikeda, T. Fukumoto, M. Oudah, J. N. Hausmann, S. Yonezawa, S. Kobayashi, M. Sato, C. Tassel, F. Takeiri, H. Takatsu, H. Kageyama, Y. Maeno,
  • Journal Title: Physica B: Condensed Matter Volume: 23 Pages: 1-5
  • DOI: 10.1016/j.physb.2017.10.089
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Theory of surface Andreev bound states and tunneling spectroscopy in three-dimensional chiral superconductors (2017)
  • Author(s): S. Tamura, S. Kobayashi, L. Bo, and Y. Tanaka
  • Journal Title: Phys. Rev. B Volume: 95 Issue: 10
  • DOI: 10.1103/physrevb.95.104511
  • Peer Reviewed / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] Anisotropic Magnetic Responses of Topological Crystalline Superconductors (2017)
  • Author(s): Y. Xiong, A. Yamakage, S. Kobayashi, M. Sato, and Y. Tanaka
  • Journal Title: Crystals Volume: 7 Issue: 2 Pages: 58-70
  • DOI: 10.3390/cryst7020058
  • NAID: 120006491838
  • Peer Reviewed / Open Access / Acknowledgement Compliant
• [Journal Article] Superconductivity in the antiperovskite Dirac-metal oxide Sr3-xSnO (2016)
  • Author(s): Mohamed Oudah, Atsutoshi Ikeda, Jan Niklas Hausmann, Shingo Yonezawa, Toshiyuki Fukumoto, Shingo Kobayashi, Masatoshi Sato, Yoshiteru Maeno
  • Journal Title: Nature Communications Volume: 7 Issue: 1 Pages: 13220-13220
  • DOI: 10.1038/ncomms13617
  • NAID: 120005895432
  • Peer Reviewed / Open Access / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] Topologically stable gapless phases in nonsymmorphic superconductors (2016)
  • Author(s): Shingo Kobayashi, Youichi Yanase, and Masatoshi Sato
  • Journal Title: Phys. Rev. B Volume: 94 Issue: 13 Pages: 1345121-11
  • DOI: 10.1103/physrevb.94.134512
  • NAID: 120005905584
  • Peer Reviewed / Acknowledgement Compliant
• [Presentation] Crossing-line-node semimetals: general theory and application to rare-earth trihydrides (2018)
  • Author(s): Shingo Kobayashi, Youichi Yamakawa, Ai Yamakage, Yoshihiko Okamoto, and Yukio Tanaka
  • Organizer: American Physical Society March Meeting 2018
  • Int'l Joint Research
• [Presentation] スピン3/2トポロジカル絶縁体の超伝導 (2018)
  • Author(s): 川上拓人、岡村鉄矢、小林伸吾、佐藤昌利
  • Organizer: 日本物理学会 第73回年次大会
• [Presentation] Fragile surface zero-energy flat bands in three-dimensional superconductors (2017)
  • Author(s): Shingo Kobayashi, Yukio Tanaka, Masatoshi Sato
  • Organizer: American Physical Society March Meeting 2017
  • Place of Presentation: Ernest N. Morial Convention Center, New Orleans
  • Year and Date: 2017-03-12
  • Int'l Joint Research
• [Presentation] Topological superconductivity in Dirac semimetals (2017)
  • Author(s): Shingo Kobayashi and Masatoshi Sato
  • Organizer: TOP-SPIN3: Spin and Topological Phenomena in Nanostructures- Towards Topological Materials Science
  • Int'l Joint Research
• [Presentation] Crossing-line-node semimetals: general theory and application to rare-earth trihydrides (2017)
  • Author(s): Shingo Kobayashi, Youichi Yamakawa, Ai Yamakage, Takumi Inohara, Yoshihiko Okamoto, and Yukio Tanaka
  • Organizer: International Conference on Topological Materials Science 2017 (TopoMat2017)
  • Int'l Joint Research
• [Presentation] 点群により保護された交差線ノード半金属 (2017)
  • Author(s): 小林伸吾、山川洋一、山影相、井ノ原拓実、岡本佳比古、田仲由喜夫
  • Organizer: 日本物理学会 2017年秋季大会
• [Presentation] 点群により保護されたラインノード半金属の分類 (2017)
  • Author(s): 小林伸吾、山川洋一、山影相、井ノ原拓実、岡本佳比古、田仲由喜夫
  • Organizer: 理研iTHES神戸量子物性研究会
  • Place of Presentation: 理化学研究所（神戸）
  • Invited
• [Presentation] 非共型対称性な超伝導体におけるノードのトポロジカル安定性 (2016)
  • Author(s): 小林伸吾、柳瀬陽一、佐藤昌利
  • Organizer: 第2回「トポロジーが紡ぐ物質科学のフロンティア」領域研究会
  • Place of Presentation: 東北大学
  • Year and Date: 2016-12-16
• [Presentation] ディラック半金属とトポロジカル超伝導 (2016)
  • Author(s): 小林伸吾、佐藤昌利
  • Organizer: 第10回物性科学領域横断研究会
  • Place of Presentation: 神戸大学
  • Year and Date: 2016-12-09
• [Presentation] 非共型対称性で保護された線ノード超伝導状態 (2016)
  • Author(s): 小林伸吾、柳瀬陽一、佐藤昌利
  • Organizer: 基研研究会「超伝導研究の最先端：多自由度、非平衡、電子相関、トポロジー」
  • Place of Presentation: 京都大学基礎物理学研究所
  • Year and Date: 2016-10-11
• [Presentation] Line nodes and surface flat band instability in odd-parity superconductors (2016)
  • Author(s): Shingo Kobayashi
  • Organizer: Superconducting Hybrid nanostructures: physics and applications
  • Place of Presentation: MITP, Moscow
  • Year and Date: 2016-09-19
  • Int'l Joint Research / Invited