title: Interaction of relativistic electron-vortex beams with few-cycle laser pulses.
abstract: We study the interaction of relativistic electron-vortex beams (EVBs) with laser light. Exact analytical solutions for this problem are obtained by employing the Dirac-Volkov wave functions to describe the (monoenergetic) distribution of the electrons in vortex beams with well-defined orbital angular momentum. Our new solutions explicitly show that the orbital angular momentum components of the laser field couple to the total angular momentum of the electrons. When the field is switched off, it is shown that the laser-driven EVB coincides with the field-free EVB as reported by Bliokh et al. [Phys. Rev. Lett. 107, 174802 (2011)]. Moreover, we calculate the probability density for finding an electron in the beam profile and demonstrate that the center of the beam is shifted with respect to the center of the field-free EVB.
authors.affiliation: Physikalisches Institut, Ruprecht-Karls-Universität Heidelberg, 69120 Heidelberg, Germany and Max-Planck-Institut für die Physik des Lichts, 91058 Erlangen, Germany.
authors.forename: Armen G
authors.initials: AG
authors.lastname: Hayrapetyan
authors.affiliation: Physikalisches Institut, Ruprecht-Karls-Universität Heidelberg, 69120 Heidelberg, Germany and GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt, Germany.
authors.forename: Oliver
authors.initials: O
authors.lastname: Matula
authors.affiliation: Max-Planck-Institut für die Physik des Lichts, 91058 Erlangen, Germany and Institute for Optics, Information and Photonics, Universität Erlangen-Nürnberg, 91058 Erlangen, Germany.
authors.forename: Andrea
authors.initials: A
authors.lastname: Aiello
authors.affiliation: Helmholtz-Institut Jena, 07743 Jena, Germany.
authors.forename: Andrey
authors.initials: A
authors.lastname: Surzhykov
authors.affiliation: Helmholtz-Institut Jena, 07743 Jena, Germany and Theoretisch-Physikalisches Institut, Friedrich-Schiller-Universität Jena, 07743 Jena, Germany.
authors.forename: Stephan
authors.initials: S
authors.lastname: Fritzsche