Ultrafast dynamics of orbital-order-induced polarization

Ultrafast photoinduced modulation is demonstrated in the orbital-order-induced polarization in manganite thin films. The evolution of the polarization modulation and the lattice temperature rise after photoexcitation are tracked separately by monitoring the relevant nonlinear optical susceptibility tensor elements. Substantial portion of the polarization disappears within the excitation pulse width (similar to 120 fs), indicating the purely electronic origin triggered by an interband excitation. We propose oxide heterostructure devices incorporating polar gating layers capable of ultrafast optical control of electronic phases. (C) 2013 AIP Publishing LLC.