Débute à 
Montréal (Québec) Canada

The discovery of topological phases of matter has profoundly impacted our understanding of solid-state physics. Its influence ranges from explaining the universality of conductivity plateaus in the quantum Hall effect to envisioning new protocols for fault-tolerant quantum computation. In the late 2000s, Nobel laureate Duncan Haldane demonstrated that this topological physics is in fact not restricted to condensed matter but can also emerge in artificial systems like photonic crystals through a careful engineering of their symmetry properties1. Since then, these photonics platforms have proven to be an amazing resource for pushing the exploration of topological physics beyond what is physically reachable in the solid-state, leading to the emergence of a blooming field called topological photonics2.

In this presentation, I will describe recent experimental works based on exciton-polaritons, a hybrid light-matter quasiparticle, which have opened new horizons in topological photonics. The main advantages of polaritonic systems arise from their dual nature: their photonic part allows for tailoring well-defined topological properties in lattices of coupled microcavities, while their matter part gives rise to a strong Kerr-like nonlinearity and to lasing3. I will first show how these properties have allowed the first realization of a topological laser, i.e. a laser where the resonating is intrinsically protected against local perturbations4. Then, I will present a recent work where we proposed and demonstrated a new scheme for measuring topological invariants in a polaritonic analog of graphene5. I will finally discuss some interesting perspectives in topological polaritonics by showing how drive and dissipation can allow stabilizing nonlinear topological excitations that have no counterparts in conservative systems6.

I will conclude this presentation by describing the research program that I want to develop, which aims at pushing this emerging field of topological photonics toward the quantum realm. More specifically, I will show how topological protection can provide a powerful asset for generating and stabilizing many-body quantum states of light and matter. Such mesoscopic quantum objects are highly desirable as they would provide an extended playground for quantum simulation, sensing applications or for generating exotic states of light such as many-body entangled states7.

Invitation Zoom:

https://umontreal.zoom.us/j/97374487015?pwd=WncySmdjQWlnWnAzUjR2OElWYUUyUT09

ID de réunion : 973 7448 7015

Code secret : deux cinq zéro quatre trois quatre

Le candidat sera disponible pour des entretiens individuels avec les membres du Département de Physique. Si vous désirez vous entretenir avec le candidat, veuillez en aviser Madame Diane Choinière.

Topological physics with light and matter: new horizons Philippe St-Jean (Anyon Systems)