Atomic-resolution spectroscopic imaging of non-centrosymmetric topological insulators

• Project/Area Number: 24684022
• Research Category: Grant-in-Aid for Young Scientists (A)
• Allocation Type: Partial Multi-year Fund
• Research Field: Condensed matter physics I
• Research Institution: The Institute of Physical and Chemical Research
• Principal Investigator: KOHSAKA Yuhki 独立行政法人理化学研究所, 創発物性科学研究センター, 上級研究員 (80455344)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Project Status: Completed (Fiscal Year 2014)
• Budget Amount: ¥28,340,000 (Direct Cost: ¥21,800,000、Indirect Cost: ¥6,540,000); Fiscal Year 2014: ¥2,340,000 (Direct Cost: ¥1,800,000、Indirect Cost: ¥540,000); Fiscal Year 2013: ¥3,120,000 (Direct Cost: ¥2,400,000、Indirect Cost: ¥720,000); Fiscal Year 2012: ¥22,880,000 (Direct Cost: ¥17,600,000、Indirect Cost: ¥5,280,000)
• Keywords: 走査トンネル顕微鏡 / Rashba効果 / トポロジカル絶縁体

Outline of Final Research Achievements

To investigate electronic states where strong spin-orbit interaction plays an important role in non-centrosymmetric materials, we have performed spectroscopic-imaging scanning tunneling microscopy of a polar semiconductor BiTeI. We showed that ambipolar two-dimensional mobile carriers on the surface were induced by the spontaneous electric polarization in the bulk. Our study demonstrates a novel means to induce non-volatile and polarity-switchable two-dimensional carriers and indicates that the surfaces of polar materials are available to explore new phenomena and functionalities.

Research Products

• [Presentation] 極性半導体BiTeIにおける両極性2次元キャリアの自発形成 (2014)
  • Author(s): 幸坂祐生, 加納学, 花栗哲郎, 髙木英典, 笹川崇男
  • Organizer: 日本物理学会2014年秋季大会
  • Place of Presentation: 中部大学
  • Year and Date: 2014-09-07
• [Presentation] Visualization of the emergence of the pseudogap state and the evolution to superconductivity in a lightly hole-doped Mott insulator
  • Author(s): 幸坂祐生
  • Organizer: Bad Metal Behavior and Mott Quantum Criticality
  • Place of Presentation: POSTECH, Pohang, South Korea
  • Invited
• [Presentation] 層状極性半導体BiTeIの走査トンネル分光
  • Author(s): 幸坂祐生, 加納学, 髙木英典, 笹川崇男
  • Organizer: 日本物理学会2013年秋季大会
  • Place of Presentation: 徳島大学
• [Presentation] Visualizing a p-n junction of two-dimensional electronic gases on a polar semiconductor BiTeI
  • Author(s): 幸坂祐生, 加納学, 花栗哲郎, 髙木英典, 笹川崇男
  • Organizer: March Meeting 2014, American Physical Society
  • Place of Presentation: Denver, CO, USA
• [Presentation] Visualizing a p-n junction of two-dimensional electronic gases on a polar semiconductor BiTeI
  • Author(s): 幸坂祐生
  • Organizer: FIRST-QS2C Workshop on "Emergent Phenomena of Correlated Materials"
  • Place of Presentation: 品川
• [Presentation] 走査型トンネル顕微鏡によるエキゾチック電子相の原子分解能分光イメージング
  • Author(s): 幸坂祐生
  • Organizer: 日本物理学会2012年秋季大会
  • Place of Presentation: 横浜国立大学
  • Invited
• [Presentation] 層状Rashba物質BiTeIの分光イメージング測定 (III)
  • Author(s): 幸坂祐生, 加納学, 髙木英典, 笹川崇男
  • Organizer: 日本物理学会2012年秋季大会
  • Place of Presentation: 横浜国立大学
  • Invited
• [Presentation] BiTeIにおける両極性スピン分裂2次元電子ガスの分光イメージング測定
  • Author(s): 幸坂祐生, 加納学, 髙木英典, 笹川崇男
  • Organizer: 日本物理学会第68回年次大会
  • Place of Presentation: 広島大学
  • Invited