Decoherence induced by Smith-Purcell radiation

TL;DR

This paper demonstrates that Smith-Purcell radiation from a conducting grating causes measurable decoherence in a double slit experiment, with fringe visibility reduction proportional to the number of grooves.

Contribution

It reveals a novel decoherence mechanism induced by Smith-Purcell radiation in interference experiments near conducting gratings.

Findings

Fringe contrast decreases with more grooves in the grating.

The effect is significant enough to be experimentally observable.

Decoherence is linked to surface currents and Smith-Purcell radiation.

Abstract

The interaction between charged particles and the vacuum fluctuations of the electromagnetic field induces decoherence, and therefore affects the contrast of fringes in an interference experiment. In this article we show that if a double slit experiment is performed near a conducting grating, the fringe visibility is reduced. We find that the reduction of contrast is proportional to the number of grooves in the conducting surface, and that for realistic values of the parameters it could be large enough to be observed. The effect can be understood in terms of the Smith-Purcell radiation produced by the surface currents induced in the conductor.