报告题目: |
Nonlinear optics with ballistic charge and spin currents in semiconductors |
报告人: |
Prof. Hui Zhao |
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University of Kansas
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报告时间: |
2011-06-14 15:00 |
报告地点: |
物理系三楼报告厅 |
主办单位: |
物理系 |
简介: |
报告摘要：
Electronic transport on nanometer dimensions is of fundamental importance in semiconductor nano-electronics and spintronics. I will discuss our recent experimental studies of ballistic charge and spin transport on nanometer length scales by using ultrafast nonlinear optical techniques. I will discuss optical injection of ballistic charge and spin currents through a coherent control technique utilizing quantum interference between one-photon and two-photon absorption pathways. I will then describe how to study the dynamics of these ballistic currents by tracking the position of the electrons with 100 femtosecond temporal resolution and sub-nanometer spatial resolution. Using these techniques, we have observed intrinsic inverse spin Hall effect, and studied ballistic charge and spin transport in several semiconductors including GaAs, silicon and germanium. Following a theoretical prediction by Jing Wang, Bang-Fen Zhu (Tsinghua University) and Ren-Bao Liu (Chinese University of Hongkong), we have observed a nonlinear optical effect, second-harmonic generation, induced by a pure spin current. Finally, I will discuss our latest experiment on using the second-harmonic generation technique to study coherent plasma oscillation in semiconductors. |
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