Frontiers in Physics

Entanglement Between Two Mechanical Oscillators in a Dual-Coupling Optomechanical System

Yujie Li, Li Deng, Tai-Shuang Yin, Aixi Chen

Published Jun 15, 2022• 4 citations

Abstract

In this study, we investigated the properties of entanglement of an optomechanical system including two mechanical oscillators, where two mechanical oscillators are coupled with the cavity field in different coupling modes: the interaction between one mechanical oscillator and cavity field is first-order coupling, and the interaction between the other and the cavity field is quadratic coupling. On the one hand, the entanglement between two mechanical oscillators is studied. The influence of the frequency of the cavity field, the mass of mechanical oscillators, and the temperature of mechanical oscillators on the entanglement between two mechanical oscillators are investigated. On the other hand, for the given parameters of the system, we also obtained the entanglement between the cavity field and the mechanical oscillator that has a quadratic coupling. Compared with the entanglement between microscopic particles, the stable macroscopic quantum entanglement between two mechanical oscillators has the characteristics of long existence life and can be reused, and it also plays an important role in quantum information processing and quantum network construction.

DOI: 10.3389/fphy.2022.908205

Related papers

Multimode strong-coupling quantum optomechanics

Hyojun Seok, Lukas F. Buchmann, Ewan M. Wright +1 more

We study theoretically the dynamics of multiple mechanical oscillators coupled to a single cavity field mode via linear or quadratic optomechanical interactions. We focus specifically on the strong-coupling regime where the cavity decays much faster than the mechanical modes, and the optomechanical coupling is comparable to or larger than the mechanical frequency, so that both the optical and mechanical systems operate in the deep quantum regime. Using the examples of one and two mechanical oscillators, we show that the system can classically exhibit bistability and bifurcations, and we explore how these manifest themselves in interference, entanglement, and correlation in the quantum theory, while revealing the impact of decoherence of the mechanical system due to cavity fluctuations and coherent driving.

arXiv:1309.7134Physical Review ADec 30, 201351 citations

Macroscopic quantum entanglement in modulated optomechanics

Mei Wang, Xin‐You Lü, Ying-Dan Wang +2 more

Quantum entanglement in mechanical systems is not only a key signature of macroscopic quantum effects but has wide applications in quantum technologies. Here we propose an effective approach for creating strong steady-state entanglement between two directly coupled mechanical oscillators (or a mechanical oscillator and a microwave resonator) in a modulated optomechanical system. The entanglement is achieved by combining the processes of a cavity cooling and the two-mode parametric interaction, which can surpass the bound on the maximal stationary entanglement from the two-mode parametric interaction. In principle, our proposal allows one to cool the system from an initial thermal state to an entangled state with high purity by a monochromatic driving laser. Also, the obtained entangled state can be used to implement the continuous-variable teleportation with high fidelity. Moreover, our proposal is robust against the thermal fluctuations of the mechanical modes under the condition of strong optical pumping.

arXiv:1712.06755Physical Review ANov 7, 2016108 citations

Phase-Controlled Entanglement in a Four-Mode Optomechanical System

Cheng Jiang, Hongxia Lu, Zhangyin Zhai +1 more

We present a scheme for realizing phase-controlled entanglement in a microwave optomechanical system comprising two microwave cavities and two mechanical oscillators. Under specific driving conditions, we show that this optomechanical interface can be exploited to generate simultaneously the stationary cavity–cavity entanglement, mechanical–mechanical entanglement, and cavity–mechanical entanglement. Due to the closed loop interaction, we find that the entanglement can be controlled flexibly by tuning the phase difference between the optomechanical coupling strengths. The dependence of the entanglement on the amplitudes of the optomechanical coupling strengths is also explored in detail. Moreover, the bipartite entanglements are robust against temperature, and it is shown that the mechanical oscillators are cooled to the ground state in the parameter regimes for observing entanglement.

PhotonicsOct 29, 20224 citations

State Transfer of Two Mechanical Oscillators in Coupled Cavity Optomechanical System

Xiao Rui-ji

This paper investigates a coupled cavity optomechanical system consisting of two Fabry-Perot cavities and the two cavities are coupled via an optical fiber.Every cavity is made of one fixed mirror and a movable mirror,and the movable mirror can be regarded as a mechanical oscillators.Meanwhile,the two cavity modes are driven by classical laser fields.So,the interaction is inevitable between cavities,cavity and moving mirror,cavity and classical field.Firstly,in order to eliminate the two cavity fields,an effective Hamiltonian of the two phonon modes is derived by means of picture transformation,adiabatic eliminating,and rotating wave approximation ignoring the high frequency items,etc.Secondly,if the two mechanical oscillators initially are in coherent states,the coupled mechanical oscillators can be used to transmit state.Finally,in order to verify the analytical result,the fidelity of quantum state is numevically simulated,the result shows that the quantum state can be transferred periodically between the two mechanical oscillators,which is the same as the analytical result.

Journal of Guangxi Normal UniversityJan 1, 20150 citations

Generation of quintupartite entanglement with an atom-assisted dual-cavity optomechanical system

Xihua Yang, Pingping Wang, Mingfei Cheng +1 more

We present a proposal to generate quintupartite entanglement with an optomechanical dual-cavity containing an ensemble of Λ-type three-level atoms. By solving the Heisenberg-Langevin equations, we show that entanglement among the two cavity fields, two mechanical oscillators, and atoms can be realized via atomic coherence and cavity field radiation pressure. In addition, within the experimentally available range of parameters, the larger the input laser power, atomic ensemble number, and quality factors of the cavity and mechanical oscillators, and the smaller the environmental temperature, the stronger the multipartite entanglement. This atom-cavity-optomechanical hybrid system provides an efficient and convenient platform for quantum states exchange between macroscopic (mechanical oscillators) and microscopic (atoms, photons) matters, and may find promising applications in realistic quantum information processing.

Journal of Modern OpticsApr 11, 20212 citations

Nonreciprocal coupling induced entanglement enhancement in a double-cavity optomechanical system

Yuan Yuan Liu, Zhi‐Ming Zhang, Jun‐Hao Liu +2 more

We investigate the quantum entanglement in a double-cavity optomechanical system consisting of an optomechanical cavity and an auxiliary cavity, where the optomechanical cavity mode couples with the mechanical mode via radiation-pressure interaction, and simultaneously couples with the auxiliary cavity mode via nonreciprocal coupling. We study the entanglement between the mechanical oscillator and the cavity modes when the two cavities are reciprocally or nonreciprocally coupled. The logarithmic negativity E n ( 1 ) ( E n ( 2 ) ) is adopted to describe the entanglement degree between the mechanical mode and the optomechanical cavity mode (the auxiliary cavity mode). We find that both E n ( 1 ) and E n ( 2 ) have maximum values in the case of reciprocal coupling. By using nonreciprocal coupling, E n ( 1 ) and E n ( 2 ) can exceed those maximum values, and a wider detuning region where the entanglement exists can be obtained. Moreover, the entanglement robustness with respect to the environment temperature is also effectively enhanced.

Chinese Physics BApr 6, 20229 citations