@article{PieplowHenkel2015, author = {Pieplow, Gregor and Henkel, Carsten}, title = {Cherenkov friction on a neutral particle moving parallel to a dielectric}, series = {Journal of physics : Condensed matter}, volume = {27}, journal = {Journal of physics : Condensed matter}, number = {21}, publisher = {IOP Publ. Ltd.}, address = {Bristol}, issn = {0953-8984}, doi = {10.1088/0953-8984/27/21/214001}, pages = {7}, year = {2015}, abstract = {We describe a simple mechanism of quantum friction for a particle moving parallel to a dielectric, based on a fully relativistic framework and the assumption of local equilibrium. The Cherenkov effect explains how the bare ground state becomes globally unstable and how fluctuations of the electromagnetic field and the particle's dipole are converted into pairs of excitations. Modeling the particle as a silver nano-sphere, we investigate the spectrum of the force and its velocity dependence. We find that the damping of the plasmon resonance in the silver particle has a relatively strong impact near the Cherenkov threshold velocity. We also present an expansion of the friction force near the threshold velocity for both damped and undamped particles.}, language = {en} } @article{IntravaiaMkrtchianBuhmannetal.2015, author = {Intravaia, Francesco and Mkrtchian, Vanik E. and Buhmann, Stefan Yoshi and Scheel, Stefan and Dalvit, Diego A. R. and Henkel, Carsten}, title = {Friction forces on atoms after acceleration}, series = {Journal of physics : Condensed matter}, volume = {27}, journal = {Journal of physics : Condensed matter}, number = {21}, publisher = {IOP Publ. Ltd.}, address = {Bristol}, issn = {0953-8984}, doi = {10.1088/0953-8984/27/21/214020}, pages = {19}, year = {2015}, abstract = {The aim of this paper is to revisit the calculation of atom-surface quantum friction in the quantum field theory formulation put forward by Barton (2010 New J. Phys. 12 113045). We show that the power dissipated into field excitations and the associated friction force depend on how the atom is boosted from being initially at rest to a configuration in which it is moving at constant velocity (nu) parallel to the planar interface. In addition, we point out that there is a subtle cancellation between the one-photon and part of the two-photon dissipating power, resulting in a leading order contribution to the frictional power which goes as nu(4). These results are also confirmed by an alternative calculation of the average radiation force, which scales as nu(3).}, language = {en} } @article{MkrtchianHenkel2014, author = {Mkrtchian, Vanik E. and Henkel, Carsten}, title = {On non-equilibrium photon distributions in the Casimir effect}, series = {Annalen der Physik}, volume = {526}, journal = {Annalen der Physik}, number = {1-2}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {0003-3804}, doi = {10.1002/andp.201300135}, pages = {87 -- 101}, year = {2014}, abstract = {The electromagnetic field in a typical geometry of the Casimir effect is described in the Schwinger-Keldysh formalism. The main result is the photon distribution function (Keldysh Green function) in any stationary state of the field. A two-plate geometry with a sliding interface in local equilibrium is studied in detail, and full agreement with the results of Rytov fluctuation electrodynamics is found.}, language = {en} }