The quantum optics of gravitational waves

TL;DR

This paper explores how quantum optics techniques can be used to analyze and detect quantum signatures of gravitational waves at interferometers, proposing methods to distinguish quantum states of GWs through observable signals.

Contribution

It introduces a novel approach to study quantum gravitational waves using quantum optics, including reconstructing classical signals and identifying experimental signatures of quantum states.

Findings

Reconstruction of classical GW signals from quantum states.

Identification of observables for future quantum GW detection.

Analysis of quantum state signatures in interferometer signals.

Abstract

By utilizing quantum optics techniques, we examine the characteristics of a quantum gravitational wave (GW) signature at interferometers. In particular, we study the problem by analyzing the equations of motion of a GW interacting with an idealized interferometer. Using this method, we reconstruct the classical GW signal from a representation of the quantum version of an almost classical monochromatic wave (a single-mode coherent state), then we discuss the experimental signatures of some specific, more general quantum states. We calculate the observables that could be used at future interferometers to probe possible quantum states carried by the gravitational waves.