Quantum synchronization of a driven self-sustained oscillator

TL;DR

This paper explores quantum synchronization in a self-sustained oscillator driven by an external force, revealing a threshold-driven transition influenced by quantum noise, with implications for fundamental physics and applications.

Contribution

It introduces a quantum-mechanical model of synchronization, analyzing the effects of quantum noise and identifying a finite threshold for synchronization unlike the classical case.

Findings

Synchronization exhibits a step-like transition with increasing drive strength.

Quantum noise diminishes the synchronized region and causes deviations from perfect locking.

A finite threshold for synchronization exists due to quantum effects.

Abstract

Synchronization is a universal phenomenon that is important both in fundamental studies and in technical applications. Here we investigate synchronization in the simplest quantum-mechanical scenario possible, i.e., a quantum-mechanical self-sustained oscillator coupled to an external harmonic drive. Using the power spectrum we analyze synchronization in terms of frequency entrainment and frequency locking in close analogy to the classical case. We show that there is a step-like crossover to a synchronized state as a function of the driving strength. In contrast to the classical case, there is a finite threshold value in driving. Quantum noise reduces the synchronized region and leads to a deviation from strict frequency locking.