Testing the equivalence principle and discreteness of spacetime through the $t^3$ gravitational phase with quantum information technology
Abstract
We propose a new thought experiment, based on presentday Quantum Information Technologies, to measure quantum gravitational effects through the BoseMarlettoVedral (BMV) effect by revealing the gravitational $t^3$ phase term, its expected relationships with lowenergy quantum gravity phenomena and test the equivalence principle of general relativity. The technique here proposed promise to reveal gravitational field fluctuations from the analysis of the stochastic noise associated to an ideal output of a measurement process of a quantum system. To improve the sensitivity we propose to cumulate the effects of the gravitational field fluctuations in time on the outputs of a series of independent measurements acted on entangled states of particles, like in the building of a quantum cryptographic key, and extract from the associated time series the effect of the expected gravitational field fluctuations. In fact, an ideal quantum cryptographic key, built with the sharing of maximally entangled states of particles, is represented by a random sequence of uncorrelated symbols mathematically described by a perfect white noise, a stochastic process with zero mean and without correlation between its values taken at different times. Gravitational field perturbations, including quantum gravity fluctuations and gravitational waves, introduce additional phase terms that decohere the entangled pairs used to build the quantum cryptographic key, with the result of coloring the white noise. We find that this setup, built with massive mesoscopic particles, can potentially reveal the $t^3$ gravitational phase term and thus, the BMV effect.
 Publication:

arXiv eprints
 Pub Date:
 August 2021
 arXiv:
 arXiv:2108.08438
 Bibcode:
 2021arXiv210808438T
 Keywords:

 General Relativity and Quantum Cosmology;
 Quantum Physics
 EPrint:
 9 pages 1 figure. arXiv admin note: substantial text overlap with arXiv:0910.2322