Polaronic Signatures in Mid-Infrared Spectra: Prediction for LaMnO3 and CaMnO3

Hole-doped LaMnO3 and electron-doped CaMnO3 form self-trapped electronic states. The spectra of these states have been calculated using a two orbital (Mn eg Jahn-Teller) model, from which the non-adiabatic optical conductivity spectra are obtained. In both cases the optical spectrum contains weight in the gap region, whose observation will indicate the self-trapped nature of the carrier states. The predicted spectra are proportional to the concentration of the doped carriers in the dilute regime, with coefficients calculated with no further model parameters.