在超快速激发电子孔等离子体后,有多少粒子相互作用会发生
R Huber1, F Tauser, A Brodschelm
1Physik-Department E11, Technische Universität München, James-Franck-Strasse, D-85748 Garching, Germany.
Nature
|November 20, 2001
概括
半导体中的库伦选显示了时间延迟. 这一发现影响了超快电子动态和量子电子设备的发展.
科学领域:
- 凝聚物质物理学 凝聚物质物理学
- 量子电子学 量子电子学
- 材料科学是一种材料科学.
背景情况:
- 静电相互作用在微观系统中至关重要.
- 在多体系统中,电荷载体被屏蔽云包围,修改了裸库伦电位.
- 半导体中的超快电子动态是先进电子设备的关键.
研究的目的:
- 研究半导体中电荷-电荷相互作用的时间演变.
- 为了确定非选的库伦碰撞是否发生在超短时间范围内.
- 了解像选和等离子体散射这样的集体现象的发生.
主要方法:
- 对充电-充电相互作用的直接时间监测.
- 在化 (GaAs) 中超快速激发电子孔等离子体.
- 使用动态选模型分析femtosecond动力学.
主要成果:
- 库伦查和等离子体散射的开始表现出时间延迟.
- 这种延迟是等离子体反射频率的顺序 (几 10^-14 秒).
- 集体行为不是在兴奋后瞬间形成的.
结论:
- 半导体中选云和集体效应的形成不是瞬间发生的.
- 在查和等离子体散射变得显著之前存在时间延迟.
- 这一时间方面对于理解超快量子运动理论至关重要.
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