Extreme Ultraviolet Transient Grating Spectroscopy of Vanadium Dioxide
  Nonlinear spectroscopy in the extreme ultraviolet (EUV) and soft x-ray spectral range offers the opportunity for element selective probing of ultrafast dynamics using core-valence transitions (Mukamel et al., Acc. Chem. Res. 42, 553 (2009)). We demonstrate a step on this path showing core-valence sensitivity in transient grating spectroscopy with EUV probing. We study the optically induced insulator-to-metal transition (IMT) of a VO2 film with EUV diffraction from the optically excited sample. The VO2 exhibits a change in the 3p-3d resonance of V accompanied by an acoustic response. Due to the broadband probing we are able to separate the two features. 
Emily Sistrunk (1), Jakob Grilj (1 and 2), Jaewoo Jeong (3), Mahesh G.   Samant (3), Alexander X. Gray (4 and 5) Hermann A. ...
physics.optics cond-mat.mtrl-sci