Philippe St-Jean, holder of a Research Chair in Quantum Photonics from the Ministère de l’Économie et de l’Innovation du Québec, studies the interaction of light and matter in the quantum regime.
When a classical light bulb is turned on, billions of electrons move in all directions and their motion emits light. Philippe St-Jean is interested in the movement of individual electrons in microscopic detail, which is governed by quantum mechanics. By placing single electrons in optical cavities, which act as sounding boards for light, he is able to tailor with a high precision the photonic modes to which they couple. For example, he can engineer cavities where light flows in a single direction or is trapped for an extended period of time.
In addition to better understanding complex quantum phenomena at the single electron level, his work paves the way to the conception of more robust and precise quantum light sources, which are particularly useful in quantum cryptography. Philippe St-Jean’s work can also be transposed to trap photons in cavity arrays to simulate new materials.
Philippe St-Jean has worked at the Centre for Nanoscience and Nanotechnology at CNRS and the University of Paris-Saclay. He became a professor in the Department of Physics in the summer of 2021.
