Nonlocal Optical Nonlinearities of Confined Exciton-Polaritons

Locality is a typical assumption in standard treatments of light-matter interactions. While violating locality is possible, experimental realizations of nonlocal optical responses are rare and typically rely on incoherent processes such as thermal or charge transport. 

Here, I will describe how we exploit quantum effects to engineer nonlocal optical nonlinearities of exciton-polaritons in a semiconductor microcavity. We apply multidimensional coherent spectroscopy in a diffraction-limited excitation geometry to demonstrate reversible coupling between quantum wavefunctions of the exciton-polaritons that exist in different regions of space. That is, the quantum pathways leading from initial optical absorption to subsequent optical emission can be steered by varying spatial excitation schemes.