Terahertz Transient Spectroscopy of Small Semiconductor Structures

9417502努尔米科本项目致力于应用高速光学和光电子学技术研究化合物半导体中小异质结构中的低维电子激发。特别是，新的太赫兹瞬变光谱方法将被应用于量子线和量子点中的少电子系统和多电子系统的量子化磁场的研究，重点是弹道和相干响应。近场成像方法将提高高振幅THz场的空间分辨率。这个项目的目的是研究小型半导体结构中的电磁运动，其尺度远小于一微米。电子可能被限制在一根非常细的导线上，或者被限制在盒子里，这将使它们更像波而不是粒子。超短激光脉冲技术被应用来提供电子激发的初始影响，并在大约一万亿分之一秒的时间尺度上跟踪它们的后续运动。特别是，将使用一种使用所谓的太赫兹技术的新的光谱安排。***

9417502 Nurmikko This poject concentrates on research in which high speed optical and optoelectronic techniques are applied to the study of lower dimensional electronic excitations in small heterostructures in compound semiconductors. In particular, new terahertz transient spectroscopic methods will be applied to the study of few and many electron systems in quantum wires and dots in quantizing magnetic fields, with emphasis on the ballistic and coherent response. Enhanced spatial resolution in high amplitude THz fields will be provided by near field imaging methods. % % % This project aims at the study of electrom motion in small semiconductor structures, on a scale much smaller than a micrometer. The electrons may be confined along a very thin wire or in a box, this will make them behave more as waves rather than particles. Ultrashort laser pulse techniques are applied to provide an initial impact of excitation of the electrons and to follow their subsequent motion on a timescale of about one trillionth of a second. In particular, a novel spectroscopic arrangement that uses so-called terahertz techniques will be employed. ***