近年来,超短激光脉冲的发展为人们在极端时间尺度上研究光与物质的相互作用提供了有效工具。皮秒时间尺度上研究磁有序材料中的自旋动力学过程已经成为凝聚态物理研究的热点,促进了自旋电子学的发展。本论文基于飞秒激光抽运一探测技术,介绍了半导体及其纳米结构中光注入自旋极化及其弛豫过程;综述了铁磁性薄膜中的超快退磁,激光诱导磁阻尼进动和逆法拉第效应;利用太赫兹脉冲的磁场分量,研究了反铁磁晶体中自旋共振模式的激发,相干控制以及自旋重取向的探测;最后介绍了超快光谱用于研究多铁性材料中电子、晶格和自旋间的耦合。了解不同材料在超快时间尺度上的磁光、光磁效应的最新进展,有助于在磁有序的超快光控制研究领域做出原创性的工作。
Recently, the development of ultrashort pulse laser technology provides an effective tool for investigating the interaction of light and matter on critical timescales. The studies on spin dynamics have become a new forefront of condensed matter physics.In this review, we attempt to analyze the rich physics of dynamical electron spins pumped and probed by time-domain optical measurements focusing on common attributes revealed by diverse materials. The spin injection and relaxation are the central problems of spintronics in semiconductors. We discuss the mechanism of ultrafast demagnetization and spin procession in magnetically ordered structures. Our interests also include the opto-magnetic effect, spin wave excitation and coherent control with THz magnetic field. Finally, important information on charge-lattice and spin-lattice coupling can be provided by ultrafast spectroscopy.