Electrical detection of nuclear spin polarization in low-dimensional electron systems baesd on semiconductors

• Project/Area Number: 24340065
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Condensed matter physics I
• Research Institution: The University of Tokyo
• Principal Investigator: MACHIDA Tomoki 東京大学, 生産技術研究所, 准教授 (00376633)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Project Status: Completed (Fiscal Year 2014)
• Budget Amount: ¥19,500,000 (Direct Cost: ¥15,000,000、Indirect Cost: ¥4,500,000); Fiscal Year 2014: ¥5,720,000 (Direct Cost: ¥4,400,000、Indirect Cost: ¥1,320,000); Fiscal Year 2013: ¥6,500,000 (Direct Cost: ¥5,000,000、Indirect Cost: ¥1,500,000); Fiscal Year 2012: ¥7,280,000 (Direct Cost: ¥5,600,000、Indirect Cost: ¥1,680,000)
• Keywords: 半導体核スピン / 量子ホール効果 / 低次元電子系 / 物性実験 / 半導体物性 / 低温物性 / 量子閉じ込め / スピンエレクトロニクス / 量子ドット

Outline of Final Research Achievements

We fabricated AlGaAs/GaAs Hall-bar devices and conducted pump&probe detection of nuclear spin polarization in two-dimensional electron gas under even filling quantum Hall regime. We detected dynamic nuclear polarization by measuring hysteresis of current-voltage characteristics. The results suggest that nuclear spin can be electrically polarized by breakdown of even filling quantum Hall effect. We also detected dynamic nuclear polarization in quantum point contact system under Kondo effect regime.

Research Products

• [Journal Article] Resistive detection of nuclear spins in a single quantum dot under Kondo effect regime (2013)
  • Author(s): M. Kawamura, D. Gottwald, K. Ono, T. Machida, and K. Kono
  • Journal Title: Phys. Rev. B Volume: 87 Issue: 8 Pages: 81303-81303
  • DOI: 10.1103/physrevb.87.081303
  • Peer Reviewed
• [Presentation] Dynamic Nuuclear Polarization Induced by Breakdown of Even-integer Quantum Hall Effect in a Corbino Ring (2012)
  • Author(s): S. Cmczawa. K. Moriya, M. Kawamura, S. Masubuchi, Y. Hashimoto, S Katsumoto, T. Machida
  • Organizer: 20th International Conference on High Magnctic Fields in Semiconductor Physics, Poster 35, 110, Chamix, France(2012)
  • Place of Presentation: Chamix, France
  • Year and Date: 2012-07-31