Photoinduced switching between charge and orbital ordered insulator and ferromagnetic metal in perovskite manganites

Photoinduced switching in perovskite manganites by irradiation of a femtosecond laser pulse was investigated on Pr-0.55(Ca1-ySry)(0.45)MnO3 locating in the critical region between the charge and orbital ordered insulator (CO/OOI) phase and the ferromagnetic metal (FM) phase. For a low excitation density, the charge and orbital order is partially melted and the microscopic quasi-FM domains are generated, which rapidly return to the CO/OOI state. When the excitation density exceeds a threshold, the CO/OOI phase transforms permanently to the FM one. The stabilization of the photoinduced FM state is attributable to the large relaxation of the lattice deformations through the percolation of the microscopic quasi-FM domains.