Generation of highly spin-polarized electron beams by using two-photon excitation process from GaAs semiconductors.

• Project/Area Number: 21740175
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Single-year Grants
• Research Field: Particle/Nuclear/Cosmic ray/Astro physics
• Research Institution: Nagoya University
• Principal Investigator: YAMAMOTO Naoto Nagoya University, 工学研究科, 助教 (60377918)
• Project Period (FY): 2009 – 2010
• Project Status: Completed (Fiscal Year 2010)
• Budget Amount: ¥4,420,000 (Direct Cost: ¥3,400,000、Indirect Cost: ¥1,020,000); Fiscal Year 2010: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000); Fiscal Year 2009: ¥2,730,000 (Direct Cost: ¥2,100,000、Indirect Cost: ¥630,000)
• Keywords: 加速器 / スピン偏極電子源 / ビーム物理 / 半導体 / スピン偏極電子 / 電子源

Research Abstract

In case that the laser power was around the threshold power of two photon excitation from GaAs semiconductors, it is found that the measured electron spin polarization (ESP) was only around 20%, which is much lower than estimated value, which is higher than 90%. It is considered that the ESP degradation is caused by the exists of harmonics in excitation laser and impurity energy states in GaAs semiconductors. To obtain higher than 90% ESP, we have to make more complicate researches & developments for laser system and sample preparation.

Research Products

• [Journal Article] Status of the high brightness polarized electron source using transmission photocathode (2011)
  • Author(s): N.Yamamoto, X.G.Jin
  • Journal Title: Journal of physics Volume: (in press)
  • Peer Reviewed
• [Journal Article] Strain of GaAs/GaAsP Superlattices Used as Spin-Polarized Electron Photocathodes, Determined by X-Ray Diffraction (2010)
  • Author(s): T.Saka, Y.Ishida, M.Kanda, X.G. Jin, Y.Maeda, S.Fuchi, T.Ujihara, Y.Takeda, T.Matsuyama, H.Horinaka, T.Kato, N.Yamamoto, A.Mano, Y.Nakagawa, M.Kuwahara, S.Okumi, T. Nakanishi, M.Yamamoto, T.Ohshima, T.Kohashi, M.Suzuki, M.Hashimoto, T.Yasue, T.Koshikawa
  • Journal Title: e-Journal of Surface Science and Nanotechnology 8 Pages: 125-130
  • NAID: 130004439219
  • Peer Reviewed
• [Journal Article] Real Time Magnetic Imaging by Spin-Polarized Low Energy Electron Microscopy with Highly Spin-Polarized and High Brightness Electron Gun (2010)
  • Author(s): M.Suzuki, M.Hashimoto, T.Yasue, T.Koshikawa, Y.Nakagawa, A.Mano, N. Yamamoto, M.Yamamoto, T.Konomi, M.Kuwahara, S.Okumi, T.Nakanishi, X.G.Jin, T.Ujihara, Y.Takeda, T. Kohashi, T.Ohshima, T.Saka, T.Kato, H.Horinaka
  • Journal Title: Applied Physics Express 3 Pages: 26601-26601
  • NAID: 10027013761
  • Peer Reviewed
• [Journal Article] Observation of Saturation Effect on Vacuum Ultraviolet Coherent Harmonic Generation at UVSOR-II (2010)
  • Author(s): T.Tanikawa, N.Yamamoto
  • Journal Title: Applied Physics Express Volume: 3
  • NAID: 10027618509
  • Peer Reviewed
• [Journal Article] Central Japan Synchrotron Radiation Research Facility Project-(II) (2010)
  • Author(s): N.Yamamoto, Y.Takeda
  • Journal Title: Proceedings of SRI09 Volume: 1234 Pages: 594-594
  • Peer Reviewed
• [Journal Article] Strain of GaAs/GaAsP Superlattices Used as Spin-Polarized Electron Photocathodes, Determined by X-Ray Diffraction (2010)
  • Author(s): T.Saka, N.Yamamoto
  • Journal Title: e-Journal of Surface Science and Nanotechnology Volume: 8 Pages: 125-130
  • NAID: 130004439219
  • Peer Reviewed
• [Journal Article] Ultra-short coherent terahertz radiation from ultrashort dips in electron bunches circulating in a storage ring (2010)
  • Author(s): N.Yamamoto, M.Shimada
  • Journal Title: Nuclear Instruments and Methods in Physics Research A Volume: (in press)
  • Peer Reviewed
• [Journal Article] Real Time Magnetic Imaging by Spin-Polarized Low Energy Electron Microscopy with Highly Spin-Polarized and High Brightness Electron Gun (2010)
  • Author(s): M.Suzuki, N.Yamamoto
  • Journal Title: Applied Physics Express Volume: 3
  • NAID: 10027013761
  • Peer Reviewed
• [Journal Article] High Brightness and high polarization electron source using transmission photocathode (2009)
  • Author(s): N.Yamamoto, X.G.Jin, A.Mano, Y. Nakagawa, T.Nakanishi, T.Ujihara, S.Okumi, M.Yamamoto, T.Konomi, Y.Takeda, T.Ohshima, T.Saka, T.Kato, H.Horinaka, T.Yasue, T. Koshikawa
  • Journal Title: Proceedings of SPIN 2008 AIP Pages: 1052-1056
• [Journal Article] Status of the high brightness polarized electron source and experimental result as a Spin-LEEM electron source
  • Author(s): N.Yamamoto, X.G.Jin, A.Mano, M. Suzuki, M.Hashimoto, T.Yasue, T.Koshikawa, T.Ujihara, Y.Takeda, T.Ohshima, T.Saka, T.Kato, H.Horinaka S.Okumi, T.Nakanishi
  • Journal Title: Proceedings of SPIN 2010, Journal of Physics : Conference Series, accepted
  • Peer Reviewed
• [Presentation] Real time observation of growth process of magnetic thin films by SPLEEM with high brightness and high spin-polarized electron source (2010)
  • Author(s): M.Suzuki
  • Organizer: 7th International Symposium on Atomic Level Characterizations for New Materials and Devices (ALC'09)
  • Place of Presentation: 米国
  • Year and Date: 2010-10-06
• [Presentation] Status of the high brightness polarized electron source and experimental result as a Spin-LEEM electron source (2010)
  • Author(s): N.Yamamoto
  • Organizer: Workshop on Sources of Polarized Electrons and High Brightness Electron Beams
  • Place of Presentation: ドイツ
  • Year and Date: 2010-09-23
• [Presentation] Status of the high brightness polarized electron source and experimental result as a Spin-LEEM electron source (2010)
  • Author(s): N.Yamamoto
  • Organizer: Workshop on Sources of Polarized Electrons and High Brightness Electron Beams (PESP10)
  • Place of Presentation: Bonn, Germany
  • Year and Date: 2010-09-23
• [Presentation] AIGaAs中間層の導入による透過型GaAs/GaAsP歪み超格子スピン偏極フォトカソードの高量子効率化 (2010)
  • Author(s): 市橋史朗
  • Organizer: 第71回応用物理学会学術講演会
  • Place of Presentation: 長崎大学
  • Year and Date: 2010-09-14
• [Presentation] 超高輝度・高スピン偏極度フォトカソード (2009)
  • Author(s): 金秀光
  • Organizer: 2009年秋第70回応用物理学会学術講演会
  • Place of Presentation: 富山大学
  • Year and Date: 2009-09-11
• [Remarks] ホームページ等
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