Measuring topological invariants in polaritonic lattices

Thanks to their versatility, photonic systems are very promising platforms for exploring topological physics beyond what is physically reachable in solid-state crystals [1] . In this sense, lattices of semiconductor microcavities confining exciton-polaritons, an hybrid quasi-particle formed from the strong coupling of optical photons and quantum well excitons, offer many advantages. For example, their intrinsic non-hermitian nature allows for probing specific topological properties efficiently and without relying on complex schemes.