Artificial quantum materials with photons: many-body physics and topology

ended

Physical systems featuring strong electronic correlations exhibit fascinating phenomena, as exemplified by high-Tc superconductivity, quantum magnetism or fractional quantum Hall physics. Inspired by these effects, new ideas have emerged to harness strongly correlated phases in artificial quantum materials, and use them as a resource for fundamental science and for quantum technology. Promising approaches for producing quantum devices are found in condensed matter platforms: one can indeed benefit from nanofabrication to engineer systems that are compact, versatile, and which can potentially be integrated in large-scale architectures. The main goal of ARQADIA is to engineer and study quantum correlated and topological phases of light using artificial photonic materials that I will fabricate in a solid-state platform. I will use exciton-polaritons in semiconductor microcavities, which are hybrid quasiparticles resulting from strong coupling between cavity photons and quantum well excitons. Polaritons are particularly attractive since they combine the best of two worlds: (i) through their photon component, they can be confined in microstrucutres and manipulated using optical spectroscopy; (ii) through their matter component, interactions between polaritons can be tuned and reinforced. Moreover, polaritons can be detected through the decay of cavity photons, which means that they naturally implement out-of-equilibrium physics and allow addressing fascinating questions related to the interplay between quantum correlations and dissipation. Within ARQADIA, I will tackle the challenge of engineering quantum correlations between polaritons via a technological breakthrough: I will insert active materials featuring strongly interacting excitons in microcavity lattices. I will use these materials to study out-of-equilibrium strongly correlated phases in vastly different regimes: from 1D to 2D, from weakly to strongly interacting and from topologically trivial to non-trivial.