CM - AMO SEMINAR <br> Exciton Interactions in Semiconductors: From Four-Wave Mixing to Patterns in Quantum Fluids
The interactions between excitons in GaAs quantum wells yield a wide variety of nonlinear optical effects. In this talk, I will first illustrate exciton-exciton interactions in a fermionic picture of electrons and holes. As an aside, I will also briefly discuss the interband dipole matrix element, which is an integral part of exciton physics, and which to this day causes much confusion in the semiconductor community. I will then discuss examples of nonlinear optical processes involving exciton-polaritons in semiconductor microcavities, including four-wave mixing, four-wave mixing instabilities, and the formation of spatial patterns in polaritonic quantum fluids.