Kaoru Yamanouchi – Institute for Attosecond Laser Facility and Department of Chemistry, University of Tokyo

Title: Quantum computing of atomic and molecular problems

Abstract: Two-dimensional analogs of metal-halide perovskites represent a promising platform for exciton-polariton-based technologies. They sustain strongly bound excitons that are stable at room temperature, readily enabling strong light-matter coupling at ambient conditions. In the strong coupling limit, uncoupled excitons have been mainly regarded as a reservoir for the polariton population. In this work, we posit that there is a bidirectional interplay between the uncoupled exciton dynamics and the polariton quantum dynamics. We fabricated a Fabry-Pérot microcavity, enclosing a two-dimensional hybrid organic-inorganic lead-iodide semiconductor, and resolved the multi-particle correlations of exciton-polaritons — that is their population and coherence dynamics — employing excitation correlation photoluminescence and two-dimensional coherent excitation spectroscopies. We find (i) an increased exciton bimolecular scattering rate of the exciton reservoir in the microcavity relative to the bare semiconductor; (ii) ultrafast population transfer from the uncoupled exciton states and the middle polariton to the lower polariton; and (iii) two-quantum correlations between polaritons and uncoupled excitons. Our work quantifies many-body correlations between bare excitons and exciton-polaritons, which are fundamental in mechanisms of the formation of polariton condensates.

Speaker Bio:Kaoru Yamanouchi  is the Director of the Institute for Attosecond Laser Facility at the University of Tokyo and a Professor at the Department of Chemistry at the University of Tokyo. His research is focused on intense laser field science, attosecond science, and quantum computing.