Femtosecond Spin Dynamics in Magnetic Semiconductor Quantum Structures

9500460 Samarth正在研究由II-VI稀磁半导体(DM)制成的量子结构中降维的量子限制对基本磁和电子自旋动力学的影响。磁光光谱探测与自旋相关的现象，如载流子的自旋反转散射、自旋相关的电子隧穿和局域化、磁极化子的形成以及自旋-晶格弛豫过程。该计划结合了最先进的飞秒光学测量技术、集成的DCSQUID技术和外延材料制造，以获得量子磁系统中动力学行为的实时视图。这个项目涉及到磁性和半导体的非常小颗粒的光学光谱学。颗粒的小尺寸以有趣的方式影响颗粒的电学性质。此外，粒子的电子性质还受其磁性的影响。这意味着半导体性质可以通过外加磁场进行调节。电学性质正在用超快光学技术进行研究。最先进的材料和实验技术对基础物理很有兴趣，并可能导致新的电子和磁性应用装置。***

9500460 Samarth The effects of reduced dimensionality a quantum confinement on fundamental magnetic and electronic spin dynamics are being investigated in quantum structures fabricated from II-VI diluted magnetic semiconductors (DMS). Magneto-optical spectroscopy probes spin-dependent phenomena such as carrier spin-flip scattering, spin dependent electronic tunneling and localization, magnetic polaron formation, and spin-lattice relaxation processes. The program combines state-of-the-art techniques in femtosecond optical measurements, integrated DCSQUID technology and epitaxial materials fabrication to obtain a real-timed view of dynamical behavior in quantum magnetic systems. % % % This project involves optical spectroscopy on very small particles that are both magnetic and semiconducting. The small size of the particles influences the electrical properties of the particles in interesting ways. In addition, the electronic properties of the particles are influenced by their magnetism. This means that the semiconducting properties can be tuned by an external magnetic fields. The electronic properties are being investigated by ultra- fast optical techniques. The state-of-the-art materials and experimental techniques are of interest for fundamental physics, and may lead to new devices for electronic and magnetic applications. ***