Decoherence induced by fluctuating boundaries

TL;DR

This paper investigates how small, random fluctuations of boundary positions in a quantum box cause the decay of quantum coherence over time, illustrating environment-induced decoherence and potential effects of spacetime fluctuations.

Contribution

It introduces a simple model demonstrating how boundary fluctuations lead to decoherence in quantum systems, linking environment effects and spacetime geometry impacts.

Findings

Interference term decays over time due to boundary fluctuations

Quantum coherence is lost at late times, transitioning to a mixed state

Model serves as an analog for spacetime geometry fluctuations

Abstract

The effects of fluctuating boundaries on a superposition state of a quantum particle in a box is studied. We consider a model in one space dimension in which the initial state is a coherent superposition of two energy eigenstates. The locations of the walls of the box are assumed to undergo small fluctuation with a Gaussian probability distribution. The spatial probability density of the particle contains an interference term, which is found to decay in time due to the boundary fluctuations. At late times, this term vanishes and the quantum coherence is lost. The system is now described by a density matrix rather than a pure quantum state.This model gives a simple illustration of how environment-induced decoherence can take place in quantum systems. It can also serve as an analog model for the effects of spacetime geometry fluctuations on quantum systems.