Generalised Einstein relation for hot Brownian motion
Institute for Theoretical Physics, University of Leipzig - Postfach 100920, 04009 Leipzig, Germany, EU
2 Institute for Experimental Physics, University of Leipzig - Linnéstraße 5, 04103 Leipzig, Germany, EU
3 Max-Planck-Institute for Mathematics in the Sciences - Inselstraße 22, 04103 Leipzig, Germany, EU
Accepted: 4 November 2011
The Brownian motion of a hot nanoparticle is described by an effective Markov theory based on fluctuating hydrodynamics. Its predictions are scrutinized over a wide temperature range using large-scale molecular dynamics simulations of a hot nanoparticle in a Lennard-Jones fluid. The particle positions and momenta are found to be Boltzmann distributed according to distinct effective temperatures THBM and Tk. For THBM we derive a formally exact theoretical prediction and establish a generalised Einstein relation that links it to directly measurable quantities.
PACS: 05.40.Jc – Brownian motion / 05.70.Ln – Nonequilibrium and irreversible thermodynamics / 47.11.Mn – Molecular dynamics methods
© EPLA, 2011