JSPS Fellowship: Investigation of Quantum Dynamics of Coherent Phonon Generation in Semiconductor Nanos

该奖项为日本札幌北海道大学David Hurley博士提供为期12个月的日本科学促进会（JSPS）博士后奖学金。Hurley博士将与应用物理系的Wright博士合作进行一项名为“半导体纳米结构中相干声子产生的量子动力学研究”的研究项目。本研究旨在对半导体薄膜和纳米结构中相干声子的产生进行必要的基础研究。在过去的三十年里，利用激光脉冲激发的晶格振动（声子）的光学产生和探测已被用于探测材料的宏观和微观性质。特别地，使用极窄时间谱（脉冲宽度~100fs）的激光脉冲进行超快产生已被用于研究半导体薄膜和纳米结构中光激发非平衡载流子和声子传播的动力学。尽管许多团体对这一领域的兴趣日益浓厚，但我们对这些材料中的声子产生和检测机制的了解仍然存在重大差距。例如，直接带隙半导体样品中的超快生成机制，就像单层砷化镓一样基本，尚未得到实验研究。这一基础研究将为研究纳米级电子学或光电器件（如半导体激光器）中与热输运和载流子弛豫相关的几何形状中相干声子的产生和传播铺平道路。* * *

Hurley 9802624 This award supports a 12 month Japan Society for the Promotion of Science (JSPS) Postdoctoral Fellowship for Dr. David Hurley at Hokkaido University in Sapporo, Japan. Dr. Hurley will work with Dr. Wright in the Department of Applied Physics on a research project entitled, "Investigation of Quantum Dynamics of Coherent Phonon Generation in Semiconductor Nanostructures." The proposed research is aimed at essential basic studies of the coherent phonon generation in semiconductor films and nanostructures. In the past thirty years, the optical generation and detection of lattice vibrations (phonons) using laser pulsed excitation has been utilized to probe macroscopic and microscopic material properties. In particular, ultrafast generation using laser pulses with extremely narrow temporal profiles (pulse width~100fs) has been used to study the dynamics of photo-excited non- equilibrium carriers and phonon propagation, in semiconductor film and nanostructures. Despite growing interest from many groups in this area there are still significant gaps in our knowledge of phonon generation and detection mechanisms in these materials. For example, the ultrafast generation mechanisms in direct band gap semiconductor samples, as basic as single layer GaAs, have not been studied experimentally. This groundwork will pave the way for the investigation of generation and propagation of coherent phonons in geometries relevant to heat transport and carrier relaxation in nanoscale electronics or optoelectronic devices such as semiconductor lasers. ***