Exciton recombination in one-dimensional organic Mott insulators

We present a theory for the recombination of (charged) holons and doublons in one-dimensional organic Mott insulators, which is responsible for the decay of the photoexcited state. Due to the charge-spin separation, the dominant mechanism for recombination at low density of charges involves a multiphonon emission. We show that a reasonable coupling to phonons is sufficient to explain the fast recombination observed by pump-probe experiments in ET−F$_2$TCNQ, whereby we can also account for the measured pressure dependence of the recombination rate