Gravitational waves, diffusion and decoherence

TL;DR

This paper investigates how gravitational waves at cosmic scales induce diffusion and decoherence in quantum systems, potentially explaining the quantum-classical boundary and suggesting experimental avenues for observation.

Contribution

It provides a quantitative analysis of gravitational wave-induced diffusion and decoherence, linking macroscopic quantum behavior to spacetime fluctuations near the Planck mass.

Findings

Gravitational waves significantly affect macroscopic quantum interferences.

Decoherence times depend on system mass and gravitational wave parameters.

Feasibility of detecting these effects with advanced matter-wave interferometry is discussed.

Abstract

The quite different behaviors exhibited by microscopic and macroscopic systems with respect to quantum interferences suggest that there may exist a naturally frontier between quantum and classical worlds. The value of the Planck mass (22$\mu$g) may lead to the idea of a connection between this borderline and intrinsic fluctuations of spacetime. We show that it is possible to obtain quantitative answers to these questions by studying the diffusion and decoherence mechanisms induced on quantum systems by gravitational waves generated at the galactic or cosmic scales. We prove that this universal fluctuating environment strongly affects quantum interferences on macroscopic systems, while leaving essentially untouched those on microscopic systems. We obtain the relevant parameters which, besides the ratio of the system's mass to Planck mass, characterize the diffusion constant and decoherence time. We discuss the feasibility of experiments aiming at observing these effects in the context of ongoing progress towards more and more sensitive matter-wave interferometry.