Polaronic signatures in the optical properties of the electron-doped cuprate superconductor Nd2-xCexCuO4

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-J model for the specific case of Nd2-xCexCuO4. 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.