Fig. 2: THz-driven nonlinear kinetics and time-resolved distribution function.
From: Non-perturbative terahertz high-harmonic generation in the three-dimensional Dirac semimetal Cd3As2
a Multicycle pump pulse of f = 0.67 THz characterized in air by its time-dependent electric field E(t). b The derived current density j(t) by solving the Boltzmann equation for τ = 10 and 30 fs, respectively, for the pump pulse with peak field strength of 110 kV/cm. c–f 3D and 2D illustration of the distribution function f(t,p) in the upper band of the Dirac cone, corresponding to τ = 10 fs for various time-delays as marked by the points 1–4 in a, b respectively. ε denotes energy. pz denotes momentum component along the linearly-polarized pump-pulse electric field. p⊥ denotes momentum in the perpendicular direction. See Supplementary Fig. 5 and Supplementary Movies 1 and 2 for more comparisons between τ = 10 and 30 fs.
