SCIENTIFIC ACCOMPLISHMENTSPolariton quantum fluidicsI co- supervised the work of three PhD students on polariton quantum fluidics. By using time-resolved homodyne detection, we observed for the first time the hydrodynamic nucleation of quantized vortices in a polariton flow scattering onto an obstacle (submitted to Nature Pyhsics).I also developed a heterodyne four-wave-mixing setup to probe the excitation spectrum of a polariton superfluid. With my colleagues, we demonstrated unambiguously the appearance of a “ghost” branch in the polariton dispersion arising from the superfluid Bogoliubov transformation (submitted to Phys. Rev. Letters). We are presently performing 2D-Fourier transform spectroscopy to investigate coherent processes arising within polariton quantum fluids. Polariton spin memoriesWe demonstrated spin multistability of microcavitiy polaritons (Published in Nat. Materials). This phenomenon had never been observed before in the condensed matter. It opens the way towards the realization of polariton-based devices such as logic gates and memories. In particular, we demonstrated recently the realization of an ultra-fast optical memory based on this phenomenon with amazing specifications: 50Gbps bit-rate and permanent storage (submitted to Nature Phot.).Spin manipulation in magnetic quantum dotsAs a PhD student, I demonstrated for the first time the detection of the spin state of a single magnetic atom (Mn) embedded in a semiconductor quantum dot (published in Phys. Rev. Letters). I demonstrated the control of the Mn spin state by tuning the charge state of the quantum dot (published in Phys. Rev. Letters). Finally, I showed the impact of the quantum dot exciton dynamics on the Mn spin relaxation time using photon correlation (published in Phys. Rev. B).