Minimal model for spontaneous quantum synchronization

TL;DR

This paper demonstrates spontaneous quantum synchronization in a simple harmonic network without nonlinearity or external driving, highlighting energy depletion and crosstalk as key mechanisms, and shows entanglement can develop during synchronization.

Contribution

It introduces the first minimal model showing quantum synchronization without nonlinearity, driving, or dissipation, using a harmonic network and Rayleigh normal modes.

Findings

Synchronization occurs in detuned oscillators without direct coupling.

Energy depletion and crosstalk facilitate synchronization.

Quantum entanglement can develop during the synchronized state.

Abstract

We show the emergence of spontaneous synchronization between a pair of detuned quantum oscillators within a harmonic network. Our model does not involve any nonlinearity, driving, or external dissipation, thus providing the simplest scenario for the occurrence of local coherent dynamics in an extended harmonic system. A sufficient condition for synchronization is established by building upon the Rayleigh normal mode approach to vibrational systems. Our results show that mechanisms favoring synchronization, even between oscillators that are not directly coupled to each other, are transient energy depletion and crosstalk. We also address the possible buildup of quantum correlations during synchronization and show that indeed entanglement may be generated in detuned systems, starting from uncorrelated states and without any direct coupling between the two oscillators.