Optical properties of lattice/magnetic small polarons from DMFT

We calculate the optical conductivity of small polarons in the Holstein and Holstein-t-J models, by applying the dynamical mean field theory. We show that the antiferromagnetic correlations tend to increase the region of the parameters where polaronic signatures are found in the optical spectra, and shift the polaronic absorption band to higher frequencies compared to the case of purely lattice polarons. On the other hand, the electron-lattice interaction is essential in order to have polaronic features in the optical absorption.