Quantum-coherent phase oscillations in synchronization

TL;DR

This paper demonstrates the existence of underdamped and quantum-coherent phase oscillations in quantum limit-cycle oscillators, revealing new regimes of quantum synchronization dynamics through an effective quantum model.

Contribution

It introduces an effective quantum model that captures underdamped phase motion and quantum coherence in quantum oscillators, advancing understanding of quantum synchronization.

Findings

Existence of underdamped quantum phase oscillations

Development of an effective quantum model for phase dynamics

Identification of quantum limit cycles of phase

Abstract

Recently, several studies have investigated synchronization in quantum-mechanical limit-cycle oscillators. However, the quantum nature of these systems remained partially hidden, since the dynamics of the oscillator's phase was overdamped and therefore incoherent. We show that there exist regimes of underdamped and even quantum-coherent phase motion, opening up new possibilities to study quantum synchronization dynamics. To this end, we investigate the Van der Pol oscillator (a paradigm for a self-oscillating system) synchronized to an external drive. We derive an effective quantum model which fully describes the regime of underdamped phase motion and additionally allows us to identify the quality of quantum coherence. Finally, we identify quantum limit cycles of the phase itself.