Correlated fluid of light : hydrodynamical and thermodynamical aspects – C-FLigHT

Light has been since the beginning of the XXth century described as a gas of photon, with limited interactions. Since the recent development in semiconductor fabrication, this picture tends to be overcome, to welcome a new analogy connecting light to fluid. Nowadays the interaction between photons can be engineered such as the light behaviour inside nano-structured devices mimic a fluid system. One of the most emblematic system described in this new paradigm is polaritonic devices.

Exciton-polariton are quasi–particle rising form the strong coupling between cavity electromagnetic modes and a quantum well exciton transition. These particles half-way between light and matter were observed in different quantum state of matter such as superfluidity and Bose-Einstein condensate paving the way for correlated fluid of light studies. The dynamic acting appears to be dominated by an interplay of strong dissipation and non-linear properties leading to rich features such as optical bistability, cavity soliton or other typical properties of non-linear dynamics. The conjonction of these outstanding features leads to unprecedented physics such as out-of-equilibrium quantum fluids, which remains mostly unexplored.

Simon Pigeon and the Quantum Optic Group at Laboratoire Kastler Brossel (Université Pierre et Marie Curie, École Normale Supérieure and CNRS) are world-recognised experts of this important field. In this project, we propose significant advances on the understanding of out-of-equilibrium quantum fluids. Moreover based on Simon Pigeon expertise, an insight of the corresponding physics will be given on through hydrodynamic and thermodynamic approaches.

— The first research line is dedicated to the in-depth study of polariton fluids properties. Focusing on the spin properties and the topological excitations taking place in such fluid, we expect to provide genuine progresses in the understanding of polariton systems and the link to other non-linear optical devices presenting similar dynamics.

?— The second component of the C-FLigHT project is to use polariton systems to simulate quantum states of matter. Thanks to the great controllability of these systems, polariton quantum fluids can provide an efficient simulator of phenomena such as Anderson localisation or Mott-Superfluid transition.

?— The third axis of C-FLigHT relies on recent advances in the emerging field of Quantum Thermodynamics. By studying microcavity polaritons from an innovative thermodynamics of open-quantum-systems perspective we expect to gain a finer understanding of these system dynamics. The goal is to describe thermodynamic phenomenon and to explore universal mechanism such as Kibble-Zurek mechanism in the general context of quantum optics and solid-state physics using polariton devices as a benchmark.

? C-FLigHT is expected to simultaneously impact two separated field of physics building a bridge in between. Quantum gas physics will gain on this project through experimenting quantum state of matter in unexplored situation, while semiconductor optical devices sciences will profit for an original insight on there devices operating behaviour. Applied and fundamental outcomes are expected from C-FLigHT, paving the way to the exploration of correlated fluid of light.