2018/06/28 by Jesper Levinsen, Francesca Maria Marchetti, Jonathan Keeling +1
Physics and Astronomy · #cond-mat.quant-gas #cond-mat.mes-hall
paper · pdf · doi:10.1103/physrevlett.123.266401
published as Phys. Rev. Lett. 123, 266401 (2019) · 6 pages, 3 figures, plus supplemental material
arxiv created 2018/06/28 · arxiv updated 2020/01/01
We investigate the many-body states of exciton-polaritons that can be observed by pump-probe spectroscopy. Here, a weak-probe `spin-down' polariton is introduced into a coherent state of `spin-up' polaritons created by a strong pump. We show that the \downarrow impurities become dressed by excitations of the \uparrow medium, and form new polaronic quasiparticles that feature two-point and three-point many-body quantum correlations, which, in the low density regime, arise from coupling to the vacuum biexciton and triexciton states respectively. In particular, we find that these correlations generate additional branches and avoided crossings in the \downarrow optical transmission spectrum that have a characteristic dependence on the \uparrow-polariton density. Our results thus demonstrate a way to directly observe correlated many-body states in an exciton-polariton system that go beyond classical mean-field theories.