Half-metallic spin dynamics at a single LaMnO_3/SrMnO_3 interface studied with nonlinear magneto-optical Kerr effect

摘要

Electronic and magnetic dynamics at a single interface of antiferromagnetic manganites, LaMnO_3/SrMnO_3. were studied with time-resolved second-harmonic generation and time-resolved nonlinear magneto-optical Kerr effect. The temporal evolution of the respective signals shows clear differences; an optical pump makes an instantaneous response of the electrons and, in contrast, induces slow demagnetization, which points to a possibility of two-dimensional half-metallic ferromagnetism for this heterointerface. Detailed analysis with various pump and probe polarizations reveals possible pathways of the optical charge-transfer excitation between Mn d orbitals, leading to a subsequent perturbation to the interface spin system.