2020/09/30 by Yuzuru Kato, Hiroya Nakao
Physics and Astronomy · #Coherence (philosophical gambling strategy) #Control theory (sociology) #Harmonic oscillator #Homodyne detection #Mechanical and Optical Resonators #Phase (matter) #Quantum #Quantum chaos and dynamical systems #Quantum fluctuation #Quantum harmonic oscillator #Synchronization (alternating current) #nlin.AO #quant-ph #stochastic dynamics and bifurcation
paper · pdf · doi:10.1088/1367-2630/abd7be
published as New J. Phys. 23 013007 (2021) · 15 pages, 9 figures
openalex created_date 2020/09/21 · openalex publication_date 2020/12/31 · arxiv created 2021/02/01 · arxiv updated 2021/02/02 · openalex updated_date 2026/08/06
Abstract We study synchronization of a quantum van der Pol oscillator with a harmonic drive and demonstrate that quantum synchronization can be enhanced by performing continuous homodyne measurement on an additional bath linearly coupled to the oscillator and applying feedback control to the oscillator. The phase coherence of the oscillator is increased by reducing quantum fluctuations via the continuous measurement, whereas the measurement backaction inevitably induces fluctuations around the phase-locking point. We propose a simple feedback policy for suppressing measurement-induced fluctuations by adjusting the frequency of the harmonic drive, which results in enhancement of quantum synchronization. We further demonstrate that the maximum enhancement of quantum synchronization is achieved by performing quantum measurement on the quadrature angle at which the phase diffusion of the oscillator is the largest and the maximal information on the oscillator phase is extracted.