磁気－プラズモンナノ構造における光－物質相互作用

磁等离子体纳米结构中的光与物质相互作用

• 批准号: 16F16358
• 负责人: 佐藤 琢哉
• 金额: $ 1.41万
• 依托单位: Kyushu University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for JSPS Fellows
• 财政年份: 2016
• 资助国家: 日本
• 起止时间: 2016-11-07 至 2019-03-31
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-16F16358/
• 关键词: garnet; pump-probe; phonon; フェムト秒光パルス; ポンプ・プローブ測定; フォノン; ラマン散乱; スピンダイナミクス

Excitation and detection of coherent quasiparticles, e.g. magnons or phonons have been attracted considerable scientific interest in the last few decades because it can be exploited to investigate the dynamical properties of wide range of materials. Among the several classes of materials, garnet belongs to an important class because it can be practically exploited for optical communication in IR regime, designing microwave filters and fabricating high frequency magneto-optical modulators. In this study, we employed femtosecond pump-probe technique to excite the coherent quasiparticle in the garnet. Our result indicates that linearly polarized pump excites the quasiparticle of frequency 4.2 THz. Importantly, 4.2 THz mode does not exhibit any noticeable change in the frequency against the temperature variation which reveals that the 4.2 THz mode is associated with the excitation of phonons, instead of magnons. A phenomenological symmetry-based theory reveals that oscillations from high frequency Eg phonon modes are excited. Selective excitation by linearly polarized pump and detection by circularly polarized probe confirms that impulsive stimulated Raman scattering (ISRS) is responsible for driving the coherent phonons in the garnet. Experimental results obtained from ISRS measurements show striking agreements with spontaneous Raman data of the garnet by taking into account the symmetry of phonon modes and corresponding excitation and detection selection rules.

相干准粒子的激发和检测，例如在过去的几十年里，磁振子或声子引起了相当大的科学兴趣，因为它可以用来研究各种材料的动力学特性。在几类材料中，石榴石属于重要的一类，因为它可以实际用于红外范围内的光通信、设计微波滤波器和制造高频磁光调制器。在这项研究中，我们采用飞秒泵浦探测技术来激发石榴石中的相干准粒子。我们的结果表明，线偏振泵激发频率为 4.2 THz 的准粒子。重要的是，4.2 THz 模式的频率相对于温度变化没有表现出任何明显的变化，这表明 4.2 THz 模式与声子而不是磁子的激发有关。基于唯象对称性的理论揭示了高频 Eg 声子模式的振荡被激发。线偏振泵的选择性激发和圆偏振探针的检测证实了脉冲受激拉曼散射（ISRS）负责驱动石榴石中的相干声子。考虑到声子模式的对称性以及相应的激发和检测选择规则，ISRS 测量获得的实验结果与石榴石的自发拉曼数据显示出惊人的一致性。

项目成果

九州大学 光物性研究室

九州大学光物理物理实验室

Femtosecond Laser Induced THz And GHz Oscillations In Rare Earth Iron Garnet

飞秒激光在稀土铁石榴石中诱导太赫兹和 GHz 振荡

• 发表时间: 2017
• 作者: P. Khan;M. Kanamaru;T. Satoh
• 通讯作者: T. Satoh

Ultrafast excitation of coherent phonons in iron garnet

铁石榴石中相干声子的超快激发

• DOI: 10.1088/1361-648x/ab1665
• 发表时间: 2019
• 期刊: J. Phys.: Condens. Matter
• 作者: P. Khan;M. Kanamaru;W. H. Hsu;M. Kichise;Y. Fujii;A. Koreeda;and T. Satoh
• 通讯作者: and T. Satoh

Femtosecond laser induced THz and GHz oscillation in iron garnet

飞秒激光在铁石榴石中诱导 THz 和 GHz 振荡

• 发表时间: 2017
• 作者: M. Kanamaru;P. Khan;and T. Satoh
• 通讯作者: and T. Satoh

Ultrafast excitation of coherent phonons in garnet

石榴石中相干声子的超快激发

• 发表时间: 2018
• 作者: M. Kanamaru;P. Khan;W. H. Hsu;M. Kichise;Y. Fujii;A. Koreeda;and T. Satoh
• 通讯作者: and T. Satoh