Relativistic quantum dynamics of a localized Dirac electron driven by an intense-laser-field pulse - art. no. 063402

The Volkov solutions for the Dirac equation are used to describe the dynami cs of an electronic wave packet interacting with a very strong laser pulse in the relativistic regime. By means of a projection method we explore the regimes of long and short laser wavelength compared to the wave packet dime nsions. Comparisons with classical electron trajectories show that the beha vior of the expectation value of the operators becomes different as we ente r to the short-wavelength regime. In addition, a study of the wave packet e volution shows unexpected features in this regime. The calculations are com pleted with an analysis of the total wave function in terms of the dynamics of its positive and negative energy components.