Coherent phonon emission in the supersonic expansion of photoexcited electron-hole plasma in Ge
Coherent phonon emission in the supersonic expansion of photoexcited electron-hole plasma in Ge
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DOI：
10.1103/physrevb.61.15837
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发表时间：
2000-06-15
影响因子：
3.7
通讯作者：
Gusev, VE
中科院分区：
文献类型：
--
作者：
Chigarev, NV;Paraschuk, DY;Gusev, VE
利用时间分辨泵浦-探测光偏转技术，对锗单晶中激光激发电子-空穴等离子体产生的相干亚纳秒声脉冲进行了探测。结果表明，这些超声波脉冲的前沿宽度由等离子体在超声速下的扩散时间控制。等离子体扩散的特征速度从实验中评估超过锗中的纵向声速的1.5倍。超声波脉冲的形状提供了证据的电子空穴等离子体在半导体在室温下的亚纳秒时间尺度上的超声扩散。
Coherent subnanosecond acoustic pulses generated by a laser-excited electron-hole plasma in a germanium single crystal are detected by a time-resolved pump-probe photodeflection technique. It is found that the front duration of these hypersound pulses is controlled by the time of plasma diffusion at supersonic velocities. The characteristic velocity of plasma diffusion evaluated from the experiments exceeds the longitudinal sound velocity in germanium by a factor of 1.5. The hypersound pulse shapes provide evidence for supersonic diffusion of the electron-hole plasma in a semiconductor at room temperature on a subnanosecond time scale.