Photoinduced melting of the orbital order in a perovskite-type vanadate LaVO3

The photoinduced dynamics in a perovskite-type vanadate LaVO3 has been studied by femtosecond time-resolved pump–probe spectroscopy. By irradiation with light in the orbital-ordered phase, an anisotropic large reflectivity change appears within the time resolution of about 200 fs. It is attributable to the instantaneous melting of the orbital order. One excitation photon is found to induce the disordering of the t2g orbitals over about 60 V-sites. The orbital order partially recovers through thermalization with the lattice vibrations in a few picoseconds.