Probing metric fluctuations with the spin decoherence of a particle in a quantum simulation
Jiannis K. Pachos, Patricio Salgado-Rebolledo, Martine Schut
Published: 2025/7/24
Abstract
Exploring potential empirical manifestations of quantum gravity is a challenging pursuit. In this study, we utilise a lattice representation of a (2+1)D massive gravity toy model interacting with Dirac fermions that can support specific spacetime fluctuations. We focus on the evolution of the fermion's spin due to its coupling to spacetime fluctuations. To monitor their dynamics a minimal model is required that comprises two bosonic modes describing spacetime geometry fluctuations coupled with the spin of the fermion. A possible emulation of this system involves encoding spin degrees of freedom in the electronic states of an atom coupled with a bimodal optical cavity that provides the two bosonic modes. The spin exhibits a variety of dynamical behaviours due to its coupling with the fluctuating geometry, with decoherence emerging as a key signature of this interaction. Our proposal introduces a novel approach for modelling the effect of interactions between quantum gravity and matter that can be probed with current technology.