Hannover 2016 – scientific programme
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Q: Fachverband Quantenoptik und Photonik
Q 58: Poster: Quantum Optics and Photonics IV
Q 58.1: Poster
Thursday, March 3, 2016, 16:30–19:00, Empore Lichthof
Quantum Friction and Markovianity — •Juliane Klatt1, Stefan Yoshi Buhmann1, and Diego A.R. Dalvit2 — 1Albert-Ludwig University, Freiburg, Germany — 2LANL, Los Alamos, NM, USA
Quantum friction is the velocity-dependent force between two polarizable objects in relative motion, resulting from quantum-fluctuation mediated transfer of energy and momentum. Due to its short-ranged nature it has proven difficult to observe.
Attempts to determine the velocity-dependence of the drag experienced by an atom moving parallel to a surface have arrived at contradicting results. Scheel and Buhmann1 predict a force linear in relative velocity v by employing the quantum regression theorem (QRT). Intravaia2, however, predicts a v3 power-law starting from a non-equilibrium fluctuation-dissipation theorem (FDT). The QRT approach assumes Markovianity, whereas the FDT does not but is restricted to stationary systems instead.
We employ the time-convolutionless expansion (TCL) for probing Markovianity and then study an atom flying towards a surface. We derive signatures of the relative motion in the atom’s decay rates and level shifts, calculate the friction experienced by the atom and compare both to results obtained from time-dependent perturbation theory.
[1] S. Scheel and S. Y. Buhmann, Phys. Rev. A 80 (2009)
[2] F. Intravaia et al., Phys. Rev. A 89 (2014)