Quantum Friction in Different Regimes

ORAL

Abstract

Quantum friction is the velocity-dependent force between two polarizable objects in relative motion, resulting from field-fluctuation mediated transfer of energy and momentum between them. Due to its short-ranged nature it has proven difficult to observe experimentally. Theoretical attempts to determine the precise velocity-dependence of the quantum drag experienced by a polarizable atom moving parallel to a surface arrive at contradicting results. Scheel\footnote{S. Scheel and S. Y. Buhmann, Phys. Rev. A {\bf80} (2009).} and Barton\footnote{G. Barton, New J. Phys. {\bf12} (2010).} predict a force linear in relative velocity $v$ -- the former using the quantum regression theorem and the latter employing time-dependent perturbation theory. Intravaia,\footnote{F. Intravaia et al., Phys. Rev. A (2014).} however, predicts a $v^3$ power-law starting from a non-equilibrium fluctuation-dissipation theorem. In order to learn where exactly the above approaches part, we set out to perform all three calculations within one and the same framework: macroscopic QED. In addition, we include contributions to quantum friction from Doppler shift and R\"ontgen interaction, which play a role for perpendicular motion and retarded distances, respectively, and consider non-stationary states of atom and field.

Authors

  • Juliane Klatt

    Albert-Ludwig University, Freiburg, Germany

  • Stefan Yoshi Buhmann

    University of Freiburg, Germany, Albert-Ludwig University, Freiburg, Germany, Albert-Ludwigs-University of Freiburg, Institute of Physics