We investigate the temperature and doping dependences of the midinfrared band in the optical conductivity of electron-doped cuprates in terms of magnetic/lattice polaron formation. We employ dynamical mean-field theory in the context of the Holstein-$t\text{−}J$ model for the specific case of ${\text{Nd}}_{2-x}{\text{Ce}}_x{\text{CuO}}_4$. We find that the onset of short-range magnetic correlations at the pseudogap temperature triggers the formation of the lattice polaron responsible for the midinfrared band.

• Received 18 November 2008

DOI:https://doi.org/10.1103/PhysRevB.79.012502