Polariton-enhanced exciton transport

Abstract

The transport distance of excitons in exciton-polariton systems has previously been assumed to be very small ($\ensuremath{\lesssim}1\phantom{\rule{0.16em}{0ex}}\ensuremath{\mu}\mathrm{m}$). The sharp spatial profiles observed when generating polaritons by nonresonant optical excitation show that this assumption is generally true. In this paper, however, we show that the transport distances of excitons in two-dimensional planar cavity structures with even a slightly polaritonic character are much longer than expected ($\ensuremath{\approx}20\phantom{\rule{0.16em}{0ex}}\ensuremath{\mu}\mathrm{m}$). Although this population of slightly polaritonic excitons is normally small compared to the total population of excitons, they can substantially outnumber the population of the polaritons at lower energies, leading to important implications for the tailoring of potential landscapes and the measurement of interactions between polaritons.