Coherent light-matter interactions: shining new light on nanotechnology

Alan Bristow
JILA and University of Colorada, Boulder

Lasers have revolutionized science and technology, enabling better understanding of light-matter interactions in a variety of media and nanostructures. Ultrafast pulses provide a snapshot of the fundamental electronic dynamics and dephasing in a material, with strong implications for device performance. Tailoring the light field in such experiments allows for coherent control of the light-matter interaction. I demonstrate optical two-dimensional Fourier-transform spectroscopy, which uses phase control of a multi-pulse excitation sequence to isolate the competing excitation pathways and disorder effects in GaAs quantum wells. Separation of these effects is important to questions relating to many-body physics. I also demonstrate quantum interference control of transient currents injected into silicon, which are detected by terahertz emission. This technique shows a novel means of making unstrained and unbiased bulk silicon into an optoelectronic material. Coherent control of light-matter interactions in real or artificial atoms and molecules will benefit the characterizing and functionality of future nanotechnologies.