Coherent Phonon Dynamics in Semiconductors and Nanotubes

技术综述：该奖项支持理论凝聚态物理的综合研究、教育和推广活动。这项研究计划的目标是发展新的理论模型，并研究半导体中相干声子的超快产生。一个关键的问题是，这种声子动力学是否可以被操纵来影响磁场和电极化到它具有器件潜力的程度。这些研究调查正在寻找三个新的领域，从理论上描述在高电场和磁场条件下，光生相干声子与纳米结构中已经存在的载流子和自旋的相互作用，以及在碳纳米管等新型材料中的相互作用。研究人员将研究利用飞秒脉冲整形来操纵电场和磁场以及载流子、声子和自旋动力学。在光学时间尺度上对磁场和电场以及载流子或自旋动力学的相干控制将对未来的器件设计产生广泛的影响。通过用相干声子控制这些特征，将为未来设备在新兴领域的应用带来各种新颖和有趣的可能性，如自旋电子学或量子信息理论。研究生将参与这项研究工作，并通过学习理论技术和了解与纳米科学相关的材料和技术而受益。这项工作将是博士学位论文研究的基础。首席研究员有担任青年学生导师和参与物理系外展工作的记录，这些活动将在本研究项目期间继续进行。非技术总结：理论凝聚态物理的综合研究、教育和外展活动结合为该奖项的核心活动。该项目的主要动机来自半导体材料中激光产生的原子振动现象，如声音。超短激光脉冲的纯频率会产生同样纯净和巨大的“声波”。它们足够大，以至于“声音”改变了材料的电磁性质。这个研究计划的目标是开发新的理论模型来理解这种影响并控制它。这种现象发生的速度极快，而且在很小的区域内发生，这一特点使人们有可能对纳米技术领域正在开发的尽可能最小的电子设备进行光学控制。研究生将参与这项研究工作，并通过学习理论技术和了解与纳米科学相关的材料和技术而受益。这项工作将是博士学位论文研究的基础。首席调查员有担任青年学生导师的记录，并参加了物理系的外联工作，这些活动将在本研究项目期间继续进行。

TECHNICAL SUMMARY:This award supports integrated research, education and outreach activities in theoretical condensed matter physics. The goal of this research program is to develop new theoretical models and investigate ultrafast generation of coherent phonons in semiconductors. A key question being addressed is whether such phonon dynamics can be manipulated to influence magnetic and electric polarization to the extent that it has device potential.These research investigations are looking into three new areas to theoretically describe the interactions of the photogenerated coherent phonons with carriers and spins that are already present in the nanostructures under conditions of high electric and magnetic fields and in novel materials such as carbon nanotubes. Researchers will investigate the use femtosecond pulse shaping to manipulate the electric and magnetic fields as well as the carrier, phonon and spin dynamics. The coherent control of magnetic and electric fields and carrier or spin dynamics on an optical time scale will have a broad impact on future device design. Through control of these features with coherent phonons, a variety of novel and interesting possibilities for future device applications in emerging fields such as spintronics or quantum information theory will be garnered. Graduate students will participate in this research effort and benefit by learning theoretical techniques and understanding the materials and technology associated with nanoscience. This work will be the basis for dissertation research leading to the PhD. The principle investigator has record of acting as a mentor of young students and participating in outreach efforts of the department of physics, activities which will continue during this research project.NON-TECHNICAL SUMMARY:Integrated research, education and outreach activities in theoretical condensed matter physics combine as the core activities under this award. The primary motivation of the project stems from the phenomena of atomic vibrations, like sound, generated by lasers in semiconductor materials. The pure frequencies of ultra short laser pulses produce similarly pure and large "sound" waves. These are sufficiently large that the "sound" alters the electric and magnetic properties of the material A goal of this research program is to develop new theoretical models to understand this effect and control it. The characteristic that this occurs extremely fast and in a small area leads to the potential for optical control of the smallest possible electronic devices that are being developed in the field of nanotechnology. Graduate students will participate in this research effort and benefit by learning theoretical techniques and understanding the materials and technology associated with nanoscience. This work will be the basis for dissertation research leading to the PhD. The principle investigator has record of acting as a mentor of young students and participating in outreach efforts of the department of physics, activities which will continue during this research project.