Ultrafast imaging of polariton propagation and interactions
Abstract
Semiconductor excitations can hybridize with cavity photons to form exciton-polaritons (EPs) with remarkable properties, including light-like energy flow combined with matter-like interactions. To fully harness these properties, EPs must retain ballistic, coherent transport despite matter-mediated interactions with lattice phonons. Here we develop a nonlinear momentum-resolved optical approach that directly images EPs in real space on femtosecond scales in a range of polaritonic architectures. We focus our analysis on EP propagation in layered halide perovskite microcavities. We reveal that EP-phonon interactions lead to a large renormalization of EP velocities at high excitonic fractions at room temperature. Despite these strong EP-phonon interactions, ballistic transport is maintained for up to half-exciton EPs, in agreement with quantum simulations of dynamic disorder shielding through light-matter hybridization. Above 50% excitonic character, rapid decoherence leads to diffusive transport. Our work provides a general framework to precisely balance EP coherence, velocity, and nonlinear interactions.
Keywords
Cite
@article{arxiv.2205.01176,
title = {Ultrafast imaging of polariton propagation and interactions},
author = {Ding Xu and Arkajit Mandal and James M. Baxter and Shan-Wen Cheng and Inki Lee and Haowen Su and Song Liu and David R. Reichman and Milan Delor},
journal= {arXiv preprint arXiv:2205.01176},
year = {2023}
}