Self-organized synchronization of mechanically coupled resonators based on optomechanics gain-loss balance

We investigate collective nonlinear dynamics in a blue-detuned optomechanical cavity that is mechanically coupled to an undriven mechanical resonator. By controlling the strength of the driving field, we engineer a mechanical gain that balances the losses of the undriven resonator. This gain-loss balance corresponds to the threshold where both coupled mechanical resonators enter simultaneously into self-sustained limit cycle oscillations regime. Rich sets of collective dynamics such as in-phase and out-of-phase synchronizations therefore emerge, depending on the mechanical coupling rate, the optically induced mechanical gain and spring effect, and the frequency mismatch between the resonators. Moreover, we introduce the quadratic coupling that induces enhancement of the in-phase synchronization. This work shows how phonon transport can remotely induce synchronization in coupled mechanical resonator array and opens up new avenues for metrology, communication, phonon-processing, and novel memories concepts.Comment: Comments are welcome

Parametrically enhancing sensor sensitivity at an exceptional point

We propose a scheme to enhance the sensitivity of Non-Hermitian optomechanical mass-sensors. The benchmark system consists of two coupled optomechanical systems where the mechanical resonators are mechanically coupled. The optical cavities are driven either by a blue or red detuned laser to produce gain and loss, respectively. Moreover, the mechanical resonators are parametrically driven through the modulation of their spring constant. For a specific strength of the optical driving field and without parametric driving, the system features an Exceptional Point (EP). Any perturbation to the mechanical frequency (dissipation) induces a splitting (shifting) of the EP, which scales as the square root of the perturbation strength, resulting in a sensitivity-factor enhancement compared with conventional optomechanical sensors. The sensitivity enhancement induced by the shifting scenario is weak as compared to the one based on the splitting phenomenon. By switching on parametric driving, the sensitivity of both sensing schemes is greatly improved, yielding to a better performance of the sensor. We have also confirmed these results through an analysis of the output spectra and the transmissions of the optical cavities. In addition to enhancing EP sensitivity, our scheme also reveals nonlinear effects on sensing under splitting and shifting scenarii. This work sheds light on new mechanisms of enhancing the sensitivity of Non-Hermitian mass sensors, paving a way to improve sensors performance for better nanoparticles or pollutants detection, and for water treatment.Comment: 12 pages, 5 figures. Comments are welcom

Self-organized synchronization of mechanically coupled resonators based on optomechanics gain-loss balance

We investigate self-organized synchronization in a blue-detuned optomechanical cavity that is mechanically coupled to an undriven mechanical resonator. By controlling the strength of the driving field, we engineer a mechanical gain that balances the losses of the undriven resonator. This gain-loss balance corresponds to the threshold where both coupled mechanical resonators enter simultaneously into self-sustained limit cycle oscillations regime. This leads to rich sets of collective dynamics such as in-phase and out-of-phase synchronizations, depending on the mechanical coupling rate, the frequency mismatch between the resonators, and the external driving strength through the mechanical gain and the optical spring effect. Moreover, we show that the introduction of a quadratic coupling, which results from a quadratically coupling of the optical cavity mode to the mechanical displacement, enhances the in-phase synchronization. This work shows how phonon transfer can optomechanically induce synchronization in a coupled mechanical resonator array and opens up new avenues for phonon processing and novel memories concepts.This work was supported by the European Commission FET OPEN H2020 project PHENOMEN-Grant Agreement No. 713450. P.D. acknowledges the funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie Grant Agreement No. 754510, and the support from Severo Ochoa Program (MINECO, Grant No. SEV-2017-0706) and funding from the CERCA Programme/Generalitat de Catalunya.Peer reviewe

Synthetic magnetism for solitons in optomechanical array

We propose a synthetic magnetism to generate and to control solitonic waves in $\rm{1D}-$optomechanical array. Each optomechanical cavity in the array couples to its neighbors through photon and phonon coupling. We create the synthetic magnetism by modulating the phonon hopping rate through a modulation frequency, and a modulation phase between resonators at different sites. When the synthetic magnetism effect is not taken into account, the mechanical coupling play a scrucial role of controlling and switching the waves from bright to dark solitons, and it even induces rogue wave-like a shape in the array. For enough mechanical coupling strength, the system enters in a strong coupling regime through splitting/crossing of solitonic waves leading to multiple waves propagation in the array. Under the synthetic magnetism effect, the phase of the modulation enables a good control of the wave propagation, and it also switches soliton shape from bright to dark, and even induces rogue waves as well. Similarly to the mechanical coupling, the synthetic magnetism offers another flexible way to generate plethora of solitonic waves for specific purposes. This work opens new avenues for optomechanical platforms and sheets light on their potentiality of controlling and switching solitonic waves based on synthetic magnetism