Strong field dynamics with ultrashort electron wave packet replicas

Abstract

We investigate theoretically electron dynamics under a VUV attosecond pulse\ntrain which has a controlled phase delay with respect to an additional strong\ninfrared laser field. Using the strong field approximation and the fact that\nthe attosecond pulse is short compared to the excited electron dynamics, we\narrive at a minimal analytical model for the kinetic energy distribution of the\nelectron as well as the photon absorption probability as a function of the\nphase delay between the fields. We analyze the dynamics in terms of electron\nwave packet replicas created by the attosecond pulses. The absorption\nprobability shows strong modulations as a function of the phase delay for VUV\nphotons of energy comparable to the binding energy of the electron, while for\nhigher photon energies the absorption probability does not depend on the delay,\nin line with the experimental observations for helium and argon, respectively.\n