Terahertz Acousto-Optics: From Nano-to Picotechnology

点击翻译按钮获取中文摘要

The proposal objective is exploration of a novel methodology, based on ultrafast acoustics, for controlling the electronic states in condensed matter systems by high intensitye strain pulses. Generated optically, these strain pulses can be well controlled with respect to their duration in the picosecond (ps) or sub-ps range and their amplitude leading to picometer (pm) crystal lattice distortions. The proposal consists of two parts: In the first one the energy levels of carriers in semiconductor quantum structures embedded in confined photon geometries shall be modulated, leading to a ps-control of energy and intensity of the spontaneous or stimulated emission from optical transitions between these levels. Eventually new regimes of quantum optics may be entered, in which the resonator vacuum field is “shaken” faster than the Rabi inverse spectral width of the optical resonance, or even faster than the inverse Rabi frequency given by the strength of light-matter interaction. Other broad fields of exploratory research will be addressed in the second part. Examples are: (1) The strain pulses may be used to realize running quantum structures moving at a speed close to thatof of sound and thereby potentially transporting carriers; (2) The modulation of electron energy levels will be transferred to other material classes such as strongly correlated materials, superconductors etc. for modifying their properties or inducing phase transitions.(3) The pulses may be used also for microscopy purposes by which internal structures may be imaged with nanometer resolution non-invasively.