Photonic Phase Control of Magnetic Oxides

Abstract
Unconventional optical responses have been revealed for the perovskite manganese oxide, Pr1-xCaxMnO3, which is known to undergo the insulatormetal (I-M) transition relevant to the magnetic field induced melting of the charge-ordered (CO) state. Optical conductivity spectrum is drastically modified over 0–1 eV from a gap-like feature into a metallic band with application of magnetic field of 7 T. It was found that such an I-M transition can be caused by photo-excitation as well. The electrical conductivity and magnetization increase abruptly with irradiation of visible/IR laser, indicating the photo-melting of the CO state and the photo-generation of ferromagnetic metallic domains.