arXiv:1204.0406 · Physical Review A

Enhancing quantum effects via periodic modulations in optomechanical systems

Alessandro Farace, Vittorio Giovannetti

Published Jul 16, 2012• 122 citations

Abstract

Parametrically modulated optomechanical systems have been recently proposed as a simple and efficient setting for the quantum control of a micromechanical oscillator: relevant possibilities include the generation of squeezing in the oscillator position (or momentum) and the enhancement of entanglement between mechanical and radiation modes. In this paper we further investigate this modulation regime, considering an optomechanical system with one or more parameters being modulated over time. We first apply a sinusoidal modulation of the mechanical frequency and characterize the optimal regime in which the visibility of purely quantum effects is maximal. We then introduce a second modulation on the input laser intensity and analyze the interplay between the two. We find that an interference pattern shows up, so that different choices of the relative phase between the two modulations can either enhance or cancel the desired quantum effects, opening new possibilities for optimal quantum control strategies.

DOI: 10.1103/physreva.86.013820

Related papers

Exploiting periodic modulations to control quantum states of optomechanical systems

Alessandro Farace, Vittorio Giovannetti

Periodically modulating an optomechanical system's parameters provides access to the quantum regime of micromechanical oscillators, enhancing squeezing, entanglement, and other relevant quantum effects.

SPIE NewsroomJul 27, 20120 citations

Manifestation of classical nonlinear dynamics in optomechanical entanglement with a parametric amplifier

Chang‐Sheng Hu, Li-Tuo Shen, Zhen‐Biao Yang +3 more

Cavity optomechanical systems involving an optical parametric amplifier (OPA) can exhibit rich classical and quantum dynamical behaviors. By simply modulating the frequency of the laser pumping the OPA, we find two interesting parameter regimes, with one of them enabling us to study quantum-classical correspondence in system dynamics, while there exist no classical counterparts of the quantum features for the other. For the detuning of the laser pumping around the mechanical frequency, as the parametric gain of OPA increases to a critical value, the classical dynamics of the optical or mechanical modes can experience a transition from the regular periodic oscillation to a period-doubling motion, in which case the light-mechanical entanglement can be well studied by the logarithmic negativity and can manifest the dynamical transition the classical nonlinear dynamics. In addition, the optomechanical entanglement shows a second-order transition characteristic at the critical parametric gain. For the laser detuning being about twice the mechanical frequency, the kind of normal mode splitting comes up in the laser detuning dependence of optomechanical entanglement, which is induced by the squeezing of the optical and mechanical hybrid modes and finds no classical correspondence. The OPA-assisted optomechanical systems therefore offer a simple way to study and exploit quantum manifestations of classical nonlinear dynamics.

arXiv:1906.06101Physical Review AOct 18, 201937 citations

Optomechanical Entanglement and Squeezing in Coherent-Feedback-assisted Quadratic Optomechanics

焦亚峰, Ruo-Chen Wang, Jingxue Liu +5 more

Quantum entanglement and squeezing associated with the motions of massive mechanical oscillators play an essential role in both fundamental science and emerging quantum technologies, yet realizing such macroscopic nonclassical states remains a formidable challenge. In this paper, we investigate how to achieve strong optomechanical entanglement and mechanical squeezing in a membrane-embedded cavity optomechanical system incorporating a coherent feedback loop, where the membrane interacts with the cavity mode through both linear and quadratic optomechanical couplings. This hybrid optomechanical architecture offers a flexible tunability of intrinsic system parameters, thereby enabling controlled stiffening or softening of the mechanical mode through adjusting quadratic optomechanical coupling, as well as effective modulation of the cavity decay rate via feedback control. More importantly, the synergistic interplay effect allows for a strategic reconfiguration of the system's stability regime, which in turn permits the presence of significantly enhanced effective optomechanical coupling strengths before entering the unstable regime. Exploiting these unique features, we demonstrate that optomechanical entanglement can be substantially enhanced with positive coupling sign and suitable feedback parameters, while strong mechanical squeezing beyond the 3dB limit is simultaneously achieved over a broad parameter range with negative coupling sign, reaching squeezing degree above 10dB under optimized conditions. Our proposal, establishing an all-optical method for generating highly entangled or squeezed states in cavity optomechanical systems, opens up a new route to explore macroscopic quantum effects and to advance quantum information processing.

Mar 24, 20260 citations

Optomechanical Entanglement and Squeezing in Coherent-Feedback-assisted Quadratic Optomechanics

焦亚峰, Ruo-Chen Wang, Jingxue Liu +5 more

Mar 24, 20260 citations

Enhancement of tripartite entanglement via periodically modulated fields with an atom-assisted optomechanical system

Jiaxin Wen, Yi Lu, Zhenghong Li +1 more

Abstract We propose a model for controlling and enhancing the entanglement between the two cavity fields and mirror with a hybrid optomechanical system consisting of Λ-type three-level 85Rb atomic ensembles driven by two externally modulated laser fields. When one (another) cavity mode is driven at the red (blue) mechanical sideband and both cavity modes are blue-detuned by the mechanical frequency to the respective atomic resonant transitions, the dynamic coupling control of the cavity field and mirror can be realized by periodically modulating the amplitudes of the two incident laser fields. Compared to the unmodulated case, the periodic modulation of the laser fields in a cavity-optomechanical system embedded with a small number of atoms has the capability to enhance the entanglement between the two cavity fields and mirror. This scheme provides a new approach to the generation and control of entanglement in cavity-optomechanical systems.

Quantum Information ProcessingMar 15, 20243 citations

Entanglement beating in a cavity optomechanical system under two-field driving

Chang‐Sheng Hu, Zhiqiang Liu, Ye Liu +3 more

An optomechanical cavity driven by a periodically amplitude-modulated laser can generate steady light-mechanical entanglement with time periodicity. Similar results can be alternatively obtained by pumping an especially tuned optical degenerate parametric amplifier (DPA) inside the cavity. While the two laser beams are simultaneously applied, the optomechanical entanglement can exhibit constructive and destructive interference patterns, depending on their cooperative phase, which further gives rise to beating in entanglement dynamics if the two modulation frequencies are slightly different, followed by a beating frequency-dependent dynamical behavior in the energy exchange between light and a mechanical oscillator. The optimal dynamical entanglement goes beyond what is attainable by the scenario with two superimposed cavity drivings, as a result of the specially DPA-modulated quantum dynamics. Moreover, we calculate correlation spectra between the cavity and mechanical modes, and we find correspondence between the light-oscillator entanglement and the correlation spectra under the cooperative effect. The cooperation-enhanced optomechanical entanglement is robust against the thermal temperature, and is potentially useful for continuous variable quantum information processing.

Physical Review AMar 10, 202037 citations