Colossal nonlinear optical magnetoelectric effects in multiferroic Bi 2FeCrO6

Abstract

Within density functional theory with the generalized gradient approximation plus on-site Coulomb repulsion method, we investigate magnetic ordering dependence of linear and nonlinear optical responses in multiferroic Bi2FeCrO6. We find that in spite of the minor difference in the linear dielectric function between ferrimagnetic state and ferromagnetic state, the second-harmonic generation susceptibility and its related linear electro-optical coefficient dramatically change. Such colossal magnetoelectric effects come mainly from the enhanced contrast in the double-photon resonance absorption between two magnetic configurations, and will open a direction in the application of conventional multiferroics via nonlinear magnetoelectric effect. © 2008 American Institute of Physics.