Strong Coupling and Long-Range Collective Interactions in Optomechanical Arrays

Abstract

We investigate the collective optomechanics of an ensemble of scatterers inside a Fabry-Pérot resonator and identify an optimized configuration where the ensemble is transmissive, in contrast with the usual reflective optomechanics approach. In this configuration, the optomechanical coupling of a specific collective mechanical mode can be several orders of magnitude larger than the singleelement case, and long-range interactions can be generated between the different elements since light permeates throughout the array. This new regime should realistically allow for achieving strong single-photon optomechanical coupling with massive resonators, realizing hybrid quantum interfaces, and exploiting collective long-range interactions in arrays of atoms or mechanical oscillators.The field of optomechanics has made tremendous progress over the past decades [1], cooling of massive mechanical oscillators to the motional quantum ground state being but one of a series of achievements that demonstrate the power of coupling light to moving scatterers [2,3]. The control of mechanical motion in the quantum regime has many important applications, ranging from precision measurements [4], quantum information processing [5], and fundamental tests of quantum mechanics [6], to the photonics sciences [7]. Despite recent progress the coupling between a single photon and a single phonon remains typically very weak, therefore necessitating the use of many photons to amplify the interaction [1,8]. In this regime, which is useful for cooling and light-motion entanglement generation, a stronger coupling per photon is desirable to limit the negative effects of using large powers, e.g., bulk temperature increases or phase-noise heating [9]. Ultimately, reaching the strong (single-photon) coupling regime, in which a single quantum of light can appreciably affect the motion of the mechanical oscillator, is essential to exploiting fully the quantum nature of the optomechanical interaction, as exhibited by such effects as the optomechanical photon blockade [10] and non-Gaussian mechanical states [11].Among the various approaches currently followed to couple mechanical oscillators with optical resonators, a successful one involves positioning reflecting objects -dielectric membranes [12,13], atoms [14], or microspheres [15] -inside an optical cavity. With dielectric membranes the optomechanical interaction strength saturates to a fundamental limit g as the reflectivity of the membrane approaches unity [12]. For a highly reflective membrane placed to the center of a Fabry-Pérot (FP) resonator of length L and resonance frequency ω, the * Corresponding author. andre.xuereb@qub.ac.uk single-photon coupling strength is given by the shift in cavity frequency when the mirror moves through a distance equal to the spread x 0 of its zero-point fluctuations, g = 2ωx 0 /L, and is typically rather weak for a macroscopic cavity [12]. Several approaches can be followed to improve quantum motional control in single membrane systems, by e.g., tailoring of the opt...

Optomechanical creation of magnetic fields for photons on a lattice

“…Several aspects have already been investigated theoretically, e.g., synchronization [8][9][10], long-range interactions [11,12], reservoir engineering [13], entanglement [14,15], correlated quantum many-body states [10], slow light [16], transport in a one-dimensional (1D) chain [17], and graphene-like Dirac physics [18].…”

Dynamic entanglement transfer in a double-cavity optomechanical system

“…Nonetheless, the indirect entanglement between the left and the right cavity is apparent in all cases, thereby facilitating a mechanism for entanglement relay through cascaded cavities although the cavities are physically not directly coupled. Such a mechanism would be useful to quantum information processing, especially in terms of non-adiabatic quantum state transfer [25,26], and would provide a physical means to realize cavity arrays or resonator waveguides for transmitting information encoded in a quantum state [27][28][29].…”

Squeezed Optomechanics with Phase-Matched Amplification and Dissipation

“…However, these effects have not yet been realized experimentally due to the intrinsically weak radiation-pressure coupling in current OMSs, i.e., g 0 κ. To achieve g 0 ∼ κ, it has been proposed to use the collective mechanical modes in transmissive scatter arrays [35,36]. The ratio g 0 /κ may also be increased in superconducting circuits using the Josephson effect, but such devices are limited to electromechanical systems [37][38][39].…”