A time-dependent theory for RABBIT

OCELLO, M; LÓPEZ, S. D.; ARBÓ, D. G.

Bariloche

Otro; AUTUMN SCHOOL ON ULTRAFAST LASERS; 2023

We study the reconstruction of attosecond harmonic beating by interference of two-photon transitions (RABBIT) technique for atomic ionization from a time-dependent viewpoint within the strong field approximation. We find that phase delays stem from the interference of the classical trajectories starting with energies corresponding to different (odd) harmonics of the fundamental frequency of the driving field (forming the attosecond pulse train) and with the same final ATI (above-threshold ionization) or sideband energy. As expected, our semiclassical description coincides with the standard RABBIT protocol for a weak probe pulse but deviates significantly as its intensity increases. We compare our time-dependent semiclassical model with the numerical solution of the strong-field approximation and find a very good resemblance. In order to include the Wigner time delays due to the long-range atomic Coulomb Potential we compare our strong-field models with results by solving numerically the time-dependent Schrödinger equation.