Electronic and optical properties of distorted rare-earth manganite under hydrostatic pressure

The effect of hydrostatic pressure on the crystal structure, electronic and optical properties of distorted rare-earth manganite TbMnO3 has been studied on the basis of first-principle calculations. The results reveal that the band gaps reduce quadratically with increasing pressure. The optical properties of TbMnO3 predict that the peaks in the dielectric function shift to higher photon energy due to the transformation of inner electronic states with increasing pressure. Otherwise, the peaks in the reflectivity spectra and loss function were also found to move to higher photon energy with pressure increasing and the relationships between the positions of these peaks and pressure can be fitted by third order polynomial expressions.