Casimir friction force between polarizable media
1 Department of Physics, Norwegian University of Science and Technology, 7491 Trondheim, Norway
2 Department of Energy and Process Engineering, Norwegian University of Science and Technology, 7491 Trondheim, Norway
Received: 13 January 2012
Published online: 13 June 2012
This work is a continuation of our recent series of papers on Casimir friction, for a pair of particles of low relative particle velocity. Each particle is modeled as a simple harmonic oscillator. Our basic method, as before, is the use of quantum mechanical statistical mechanics, involving the Kubo formula, at finite temperature. In this work we begin by analyzing the Casimir friction between two particles polarizable in all spatial directions, this being a generalization of our study in [J.S. Høye, I. Brevik, Europhys. Lett. 91, 60003 (2010)], which was restricted to a pair of particles with longitudinal polarization only. For simplicity the particles are taken to interact via the electrostatic dipole-dipole interaction. Thereafter, we consider the Casimir friction between one particle and a dielectric half-space, and also the friction between two dielectric half-spaces. Finally, we consider general polarizabilities (beyond the simple one-oscillator form), and show how friction occurs at finite temperature when finite frequency regions of the imaginary parts of polarizabilities overlap.
Key words: Atomic Physics
© EDP Sciences, Società Italiana di Fisica and Springer-Verlag 2012