Terahertz, High Electric Field Quantum Transport in Verticaland Lateral Superlattices

半导体超晶格和纳米结构中的电输运有望在大的高频电场中表现出强烈的非线性。这些场和频率可以从加州大学圣巴巴拉分校的自由电子激光设备获得。本研究聚焦于半导体超晶格和多量子阱中的动态局域化、强、高频电场下电导的猝灭以及光子辅助隧穿。垂直和横向超晶格和纳米结构将被研究。现代材料的合成和加工使研究人员能够制造出非常小的半导体结构，以至于电子的“波动性质”可以控制它们的电性能。这些半导体纳米结构的特点是电子电流对施加电压的非线性依赖，使人想起变压器在许多日常应用中的工作方式。然而，这项研究解决了比普通变压器快数百万倍的电响应，因此可能会导致新设备的发展，其工作频率甚至超过飞机工业中常见的雷达频率。

Electrical transport in semiconductor superlattices and nanostructures is expected to exhibit strong non-linearities in large, high frequency electric fields. Such fields and frequencies are available from the Free Electron Laser Facility at UC Santa Barbara. This research focuses on dynamic localization, quenching of the conductance in the presence of strong, high frequency, electric fields, and photon assisted tunneling in semiconductor superlattices and multi-quantum wells. Both vertical and lateral superlattices and nanostructures will be investigated. %%% Modern materials synthesis and processing has enabled researchers to fabricate semiconductor structures that are so small that the "wave nature" of the electron controls their electrical properties. These semiconductor nanostructures are characterized by a very non- linear dependence of electron current on applied voltage, reminiscent of how a transformer works in many everday applications. However, this research addresses electrical responses many millions of times faster than in ordinary transformers, and hence may lead to the development of new devices which function at frequencies beyond even the radar frequencies common in the aircraft industry.