# Lateral Casimir-Polder forces by breaking time-reversal symmetry. (arXiv:1712.04327v1 [quant-ph])

We examine the lateral Casimir-Polder force acting on a circular rotating

emitter near a dielectric plane surface. As the circular motion breaks

time-reversal symmetry, the spontaneous emission in a direction parallel to the

surface is in general anisotropic. We show that a lateral force arises which

can be interpreted as a recoil force because of this asymmetric emission. The

force is an oscillating function of the distance between the emitter and the

surface, and the lossy character of the dielectric strongly influences the

results in the near-field regime. The force exhibits also a population-induced

dynamics, decaying exponentially with respect to time on timescales of the

inverse of the spontaneous decay rate. We propose that this effect could be

detected measuring the velocity acquired by the emitter, following different

cycles of excitation and thermalisation. Our results are expressed in terms of

the Green's tensor and can therefore easily be applied to more complex

geometries.