Fig. 2: Spatial dependence of the insulator-to-metal transition.
From: Ultrafast X-ray imaging of the light-induced phase transition in VO2
a, Full-field FTH images of pump-induced change in the real part (Re) of the transmission (T) images as a function of pump–probe delay. b, Comparison of the principal component (PC) obtained from a with a static two-colour difference image (529.5 eV and 531.25 eV) showing that regions that show increased (decreased) transmission correspond to regions starting in the green R (purple M1) phase. These early-time dynamics can be modelled as a double exponential decay with time constants τ1 = 203 ± 18 fs and τ2 = 4.98 ± 0.04 ps, corresponding to a near-resolution limited drop and a slower evolution respectively (see methods).
