Non-equilibrium quadratic measurement-feedback squeezing in a micromechanical resonator

Abstract

Measurement and feedback control of stochastic dynamics has been actively studied for not only stabilizing the system but also for generating additional entropy flows originating in the information flow in the feedback controller. In particular, a micromechanical system offers a great platform to investigate such non-equilibrium dynamics under measurement-feedback control owing to its precise controllability of small fluctuations. Although various types of measurement-feedback protocols have been demonstrated with linear observables (e.g., displacement and velocity), extending them to the nonlinear regime, i.e., utilizing nonlinear observables in both measurement and control, retains non-trivial phenomena in its non-equilibrium dynamics. Here, we demonstrate measurement-feedback control of a micromechanical resonator by driving the second-order nonlinearity (i.e., parametric squeezing) and directly measuring quadratic observables, which are given by the Schwinger representation of pseudo angular momentum (referred as Schwinger angular momentum). In contrast to that the parametric divergence occurs when the second-order nonlinearity is blindly driven, our measurement-feedback protocol enables us to avoid such a divergence and to achieve a strong noise reduction at the level of $-5.1\pm 0.2$ dB. This strong noise reduction originates in the effective cooling included in our measurement-feedback protocol, which is unveiled by investigating entropy production rates in a coarse-grained model. Our results open up the possibility of not only improving noise-limited sensitivity performance but also investigating entropy production in information thermodynamic machines with nonlinear measurement and feedback.

References in corpus (29)

• Information heat engine: converting information to energy by feedback control
• Cooling of a mirror by radiation pressure
• Feedback cooling of a cantilever's fundamental mode below 5 mK
• Coherent phonon manipulation in coupled mechanical resonators
• Nonequilibrium Thermodynamics of Feedback Control
• Speed Limit for Classical Stochastic Processes
• An experimental test of the Jarzynski equality in a mechanical experiment
• Dynamic Relaxation of a Levitated Nanoparticle from a Non-Equilibrium Steady State
• Coherent control of a nanomechanical two-level system
• Entropy production and time asymmetry in nonequilibrium fluctuations
• Nonlinear cavity optomechanics with nanomechanical thermal fluctuations
• Non-linear optomechanical measurement of mechanical motion
• Entropy production in full phase space for continuous stochastic dynamics
• Second-law-like inequalities with information and their interpretations
• An electromechanical Ising machine
• Stochastic time-evolution, information geometry and the Cramer-Rao Bound
• High quality factor graphene-based 2D heterostructure mechanical resonator
• Two-mode squeezing in an electromechanical resonator
• Fluctuation relations for a driven Brownian particle
• Entanglement criteria via the uncertainty relations in su(2) and su(1,1) algebra: detection of non-Gaussian entangled states
• Entropy production and fluctuation theorems for Langevin processes under continuous non-Markovian feedback control
• Parametric oscillation, frequency mixing and injection locking of strongly coupled nanomechanical resonator modes
• Feedback-enhanced parametric squeezing of mechanical motion
• Thermodynamics of continuous non-Markovian feedback control
• A mechanical autonomous stochastic heat engine
• Experimental assessment of entropy production in a continuously measured mechanical resonator
• Entropy production and fluctuation theorems under feedback control: the molecular refrigerator model revisited
• Classical non-Gaussian state preparation through squeezing in an opto-electromechanical resonator
• Optically probing Schwinger angular momenta in a micromechanical resonator