Dissipation and decoherence effects on a moving particle in front of a dielectric plate

TL;DR

This paper investigates how vacuum fluctuations cause dissipation and decoherence in a moving particle near a dielectric plate, analyzing effects of velocity, microscopic properties, and the presence of a mirror.

Contribution

It introduces a detailed theoretical framework to quantify dissipation and decoherence effects on a particle near a dielectric surface, considering velocity and microscopic properties.

Findings

Dissipation probability increases with particle velocity.

Decoherence time depends on the microscopic properties of the particle and the environment.

Presence of a mirror can modulate decoherence effects.

Abstract

On this work, we consider a particle moving in front of a dielectric plate, and study two of the most relevant effects of the vacuum field fluctuations: the dissipation, and the decoherence of the particle's internal degrees of freedom. We consider the particle to follow a classical, macroscopically-fixed trajectory. To study the dissipative effects, we calculate the in-out effective action by functionally integrating over the vacuum field and the microscopic degrees of freedom of both the plate and the particle. This in-out effective action develops an imaginary part, hence a non-vanishing probability for the decay (because of friction) of the initial vacuum state. We analyze how the dissipation is affected by the relative velocity between the particle and the plate and the properties of the microscopic degrees of freedom. In order to study the effects of decoherence over the internal degrees of freedom of the particle, we calculate the CTP or Schwinger-Keldysh influence action, by functionally integrating over the vacuum field and the microscopic degrees of freedom of the plate. We estimate the decoherence time as the time needed by two different quantum configurations (of the internal degree of freedom of the particle) to be possible to differentiate from one another. We analyze the way in which the presence of the mirror affects the decoherence, and the possible ways to maximize or reduce its effects.