Quantum synchronization effects induced by strong nonlinearities

TL;DR

This paper introduces a new quantum oscillator model that captures strong nonlinear effects, revealing phenomena like persistent amplitude death and enhanced synchronization bandwidth in quantum regimes, which are absent in classical analogs.

Contribution

The authors propose a novel model for quantum oscillators with strong nonlinearities, enabling the study of deep-quantum phenomena beyond the weak nonlinearity limit.

Findings

Persistence of amplitude death on resonance in strongly nonlinear quantum oscillators

Nonlinearity-induced position correlations in reactively coupled oscillators

Enlarged synchronization bandwidth due to strong nonlinearity

Abstract

A paradigm for quantum synchronization is the quantum analog of the Stuart--Landau oscillator, which corresponds to a van der Pol oscillator in the limit of weak (i.e. vanishingly small) nonlinearity. Due to this limitation, the quantum Stuart--Landau oscillator fails to capture interesting nonlinearity-induced phenomena such as relaxation oscillations. To overcome this deficiency we propose an alternative model which approximates the van der Pol oscillator to finitely large nonlinearities while remaining numerically tractable. This allows us to uncover interesting phenomena in the deep-quantum strongly-nonlinear regime with no classical analog, such as the persistence of amplitude death on resonance. We also report nonlinearity-induced position correlations in reactively coupled quantum oscillators. Such coupled oscillations become more and more correlated with increasing nonlinearity before reaching some maximum. Again, this behavior is absent classically. We also show how strong nonlinearity can enlarge the synchronization bandwidth in both single and coupled oscillators. This effect can be harnessed to induce mutual synchronization between two oscillators initially in amplitude death.