Reduced exciton-exciton scattering in quantum wires

A nonthermal, quasimonoenergetic exciton distribution is observed in time-resolved photoluminescence measurements up to 150 ps after excitation if a quantum wire is excited resonantly and with low excitation density of ${10}^2$ ${\mathrm{cm}}^{\mathrm{-}1}$. The scattering rate increases only slowly with increasing exciton density. This is the first evidence in optical experiments for strongly reduced exciton-exciton scattering rates in one-dimensional systems.