Novel method to polarize nuclei by short laser pulses

• Project/Area Number: 17204017
• Research Category: Grant-in-Aid for Scientific Research (A)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Particle/Nuclear/Cosmic ray/Astro physics
• Research Institution: Kyoto University
• Principal Investigator: NAKAJIMA Takashi 京都大学, エネルギー理工学研究所, 准教授 (50281639)
• Co-Investigator(Kenkyū-buntansha): SAKKA Tetsuo 京都大学, エネルギー理工学研究所, 准教授 (10196206) ; MATSUO Yukari 理化学研究所, 先任研究員 (50231593) ; KOBAYASHI Tohru 理化学研究所, 先任研究員 (70202067)
• Project Period (FY): 2005 – 2007
• Project Status: Completed (Fiscal Year 2007)
• Budget Amount: ¥38,610,000 (Direct Cost: ¥29,700,000、Indirect Cost: ¥8,910,000); Fiscal Year 2007: ¥12,220,000 (Direct Cost: ¥9,400,000、Indirect Cost: ¥2,820,000); Fiscal Year 2006: ¥13,260,000 (Direct Cost: ¥10,200,000、Indirect Cost: ¥3,060,000); Fiscal Year 2005: ¥13,130,000 (Direct Cost: ¥10,100,000、Indirect Cost: ¥3,030,000)
• Keywords: 核スピン / 偏極 / コヒーレンス / 光イオン化 / レーザーアプレーション / 倫極 / レーザーアブレーション

Outline of Final Research Achievements

基底状態にあるアルカリ土類金属原子を短レーザーパルスによって複数の超微細準位にコヒーレントに励起すると, 核スピン偏極がI=1/2の核種については最大89%, I=3/2の核種については最大76%にまで数ナノ秒の時間スケールで変動することを理論的に示した。これは, 超高速核スピン偏極が理論的に可能であることを示すものであり, 寿命の短い不安定核種へも原理的に応用できると言う点で原子核物理学の研究に大きく寄与する。
また, 核スピン偏極の実験実証に先んじて, 超高速電子スピン偏極を世界で初めて実験的に観測した。得られた結果は我々のab-initio理論計算の結果と良く一致した。

Research Products

• [Journal Article] All-optical control and direct detection of ultrafast spin-polarization in a multi-valence-electron system (2008)
  • Author(s): T. Nakajima, Y. Matsuo, T. Kobayashi
  • Journal Title: Physical Review A 77
  • Peer Reviewed
• [Journal Article] Investigation of ultrafast nuclear spin polarization induced by short laser pulses (2007)
  • Author(s): Takashi Nakajima
  • Journal Title: Physical Review Letters 99
  • Peer Reviewed
• [Journal Article] Spin-polarization using optical methods (2007)
  • Author(s): Takashi Nakajima
  • Journal Title: Proceedings of the 11^<th> International Workshopon Polarized Sources and Targets Pages: 195-200
• [Journal Article] Nuclear spin polarization induced by ultrafast laser pulses (2007)
  • Author(s): Takashi Nakajima
  • Journal Title: AIP Conference Proceedings 915 Pages: 996-1001
• [Journal Article] Ultrafast Nuclear Spin Polarization by Short Laser Pulses (2007)
  • Author(s): Takashi Nakajima
  • Journal Title: AIP Conference Proceedings 980 Pages: 289-294
• [Journal Article] Photoionization characteristics of Sr into 6skl continua through the spin-resolved ion detection by laser-induced fluorescence (2007)
  • Author(s): Y. Matsuo, T. Kobayashi, N. Yonekura, and T. Nakajima:
  • Journal Title: Japanese Journal Applied Physics 46 Pages: 1181-85
• [Journal Article] パルスレーザー誘起スピン偏極 (2007)
  • Author(s): 中嶋 隆
  • Journal Title: 日本物理学会誌 62 Pages: 230-238
  • NAID: 110006242010
• [Journal Article] Effects of laser intensity and applied electric field on coherent control of spin polarization by short laser pulses (2006)
  • Author(s): T.Nakajima
  • Journal Title: Applied Physics Letters 88 Pages: 111105-111107
• [Presentation] First step toward ultrafast nuclear-spin polarization: All-optical control and direct detection of ultrafast electron-spin polarization using fs laser pulses (2008)
  • Author(s): T. Nakajima, Y. Matsuo, T. Kobayashi
  • Organizer: 18th International Spin Physics Symposium (SPIN2008)
  • Place of Presentation: Virginia, USA
  • Year and Date: 2008-10-09
• [Presentation] Ultrafast Nuclear Spin Polarization by Short Laser Pulses (2007)
  • Author(s): T. Nakajima
  • Organizer: 12th InternationaI Workshop on Polarized Sources, Targets & Polarimetry (PSTP07)
  • Place of Presentation: Brookhaven, USA
  • Year and Date: 2007-09-10
• [Presentation] Experimental observation and control of ultrafast spin-polarization using fs laser pulses (2007)
  • Author(s): Y. Matsuo, T. Kobayashi, T. Nakajima
  • Organizer: 16^<th> International Laser Physics Workshop (LPHYS'07)
  • Place of Presentation: Leon, Mexico
  • Year and Date: 2007-08-23
• [Patent(Industrial Property Rights)] 核スピン偏極装置及び該方法 (2006)
  • Inventor(s): 中嶋 隆
  • Industrial Property Rights Holder: 京都大学
  • Industrial Property Number: 2006-269108
  • Filing Date: 2006-09-29