Switching effect upon the quantum Brownian motion near a reflecting boundary

TL;DR

This paper studies how smooth switching functions affect the measurement of quantum Brownian motion of a charged particle near a reflecting boundary, revealing significant differences from sudden switching and emphasizing the role of anti-correlations.

Contribution

It introduces a realistic smooth switching model and demonstrates its substantial impact on quantum Brownian motion measurements near boundaries, highlighting the importance of switching effects.

Findings

Switching tails significantly influence measurement outcomes.

Smooth switching results differ qualitatively from sudden switching.

Anti-correlations are crucial in the switching effect.

Abstract

The quantum Brownian motion of a charged particle in the electromagnetic vacuum fluctuations is investigated near a perfectly reflecting flat boundary, taking into account the smooth switching process in the measurement. Constructing a smooth switching function by gluing together a plateau and the Lorentzian switching tails, it is shown that the switching tails have a great influence on the measurement of the Brownian motion in the quantum vacuum. Indeed, it turns out that the result with a smooth switching function and the one with a sudden switching function are qualitatively quite different. It is also shown that anti-correlations between the switching tails and the main measuring part plays an essential role in this switching effect. The switching function can also be interpreted as a prototype of an non-equilibrium process in a realistic measurement, so that the switching effect found here is expected to be significant in actual applications in vacuum physics.