Quantum synchronization

G. J. Qiao, X. Y. Liu, H. D. Liu +2 more

Based on the concepts of quantum synchronization and quantum phase synchronization proposed by A. Mari et al. [Phys. Rev. Lett. 111, 103605 (2013)], we introduce and characterize the measure of a more generalized quantum synchronization called quantum $\ensuremath{\phi}$ synchronization under which pairs of variables have the same amplitude and possess the same $\ensuremath{\phi}$ phase shift. Naturally, quantum synchronization and quantum antisynchronization become special cases of quantum $\ensuremath{\phi}$ synchronization. Their relations and differences are also discussed. To illustrate these theories, we investigate the quantum $\ensuremath{\phi}$ synchronization and quantum phase synchronization phenomena of two coupled optomechanical systems with periodic modulation and show that quantum $\ensuremath{\phi}$ synchronization is more general as a measure of synchronization. We also show the phenomenon of quantum antisynchronization when $\ensuremath{\phi}=\ensuremath{\pi}$.

O. V. Zhirov, Dima L. Shepelyansky

O. V. Zhirov, Dima L. Shepelyansky

Wenlin Li, Chong Li, He‐Shan Song

Abstract We propose a quantitative criterion to determine whether the coupled quantum systems can achieve complete synchronization or phase synchronization in the process of analyzing quantum synchronization. Adopting the criterion, we discuss the quantum synchronization effects between optomechanical systems and find that the error between the systems and the fluctuation of error is sensitive to coupling intensity by calculating the largest Lyapunov exponent of the model and quantum fluctuation, respectively. By taking the appropriate coupling intensity, we can control quantum synchronization even under different logical relationships between switches. Finally, we simulate the dynamical evolution of the system to verify the quantum synchronization criterion and to show the ability of synchronization control.

Gaurav M. Vaidya, Simon B. Jäger, Athreya Shankar

We study the phenomenon of quantum synchronization from the viewpoint of quantum metrology. By interpreting quantum self-sustained oscillators as dissipative quantum sensors, we develop a framework to characterize several aspects of quantum synchronization. We show that the quantum Fisher information (QFI) serves as a system-agnostic measure of quantum synchronization that also carries a clear operational meaning, viz., it quantifies the precision with which the amplitude of a weak synchronizing drive can be measured. We extend our analysis to study many-body oscillators subjected to multiple drives. We show how the QFI matrix can be used to determine the optimal drive that maximizes quantum synchronization, and also to quantitatively differentiate the synchronization responses induced by different drives. Our work highlights multiple connections between quantum synchronization and quantum metrology, paving a route toward finding quantum technological applications of quantum synchronization.

V. P. Chebotaev