Fig. 6: Reflectivity changes in the Mott-gap transition band in the near-infrared (NIR) region induced by the mid-infrared (MIR)-pump pulse.
a Schematic of the experimental setup. b Time characteristic of the reflectivity (R) change ΔR(t)/R at 0.71 eV at 294 K for the MIR pulse with the maximum electric-field amplitude, EMIR, of 6.0 MV cm−1 (the black solid line). The red solid line represents five times ΔR(t)/R. c Time characteristic of the oscillatory component, ΔROSC(t)/R, (open circles). The red line shows the fitting curve. Time characteristics of oscillatory components B, C, and D determined by the fitting procedure are shown by the green, blue, and purple solid lines, respectively. d The R spectrum for the electric field of light E parallel to the a axis (E//a) (the black solid line) due to the Mott-gap transition band and ΔR(t) spectra at the delay time of the probe pulse relative to the MIR-pump pulse, t = 1 ps, 2 ps, and 5 ps (the red triangles, the blue circles and green squares, respectively). The error bars are smaller than the sizes of data points. The red broken line shows the simulation curve.
