We compute the time-resolved photoemission spectrum after photo-doping in a two-dimensional Mott-Hubbard insulator. We find that the relaxation rate of high-energy photo-doped electrons in the paramagnetic phase scales with the strength of the nearest-neighbor spin correlations, which implies a pronounced increase of the relaxation times with temperature and excitation density. Finite doping, in contrast, opens additional scattering channels and leads to a faster relaxation. To obtain our results we have implemented a nonequilibrium version of the dynamical cluster approximation (DCA), which, in contrast to single-site dynamical mean-field theory, captures the effect of short-range correlations.
@article{arxiv.1410.3956,
title = {Ultra-fast photo-carrier relaxation in Mott insulators with short-range spin correlations},
author = {Martin Eckstein and Philipp Werner},
journal= {arXiv preprint arXiv:1410.3956},
year = {2016}
}