Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Physical Review A

Strong mechanical squeezing and optomechanical steering via continuous monitoring in optomechanical systems

Huatang Tan, Huiping Zhan

Published Aug 27, 2019• 10 citations
Publisher

Abstract

In this paper, we first consider the generation of mechanical squeezing in a dispersively or dissipatively coupled optomechanical system by continuously homodyning the output field of the optomechanical cavity. It is found that strong steady-state mechanical squeezing beyond the 3 dB limit can be achieved in both of the optomechanical systems. The properties of the squeezing are quite different for the two types of systems and the reasons for the differences are analyzed. We next consider the achievement of optomechanical steering in the dispersive or dissipative optomechanical system via continuously monitoring the position of the mechanical oscillator. It is revealed that the monitoring can lead the steady-state optomechanical entanglement to be enhanced considerably such that strong steerable correlations can be achieved between the mechanical oscillator and the cavity field. The effects of thermal phonons are studied and it is shown that the generated squeezing and steering are quite robust against the thermal fluctuations.

DOI
10.1103/physreva.100.023843

Related papers

Generation of squeezed states and single-phonon states via homodyne detection and photon subtraction on the filtered output of an optomechanical cavity

Guifeng Huang, Wenwu Deng, Huatang Tan +1 more

In this paper, we consider the generation of mechanical squeezed states and single-phonon Fock states, respectively, by homodyne detection and photon subtraction in a dissipative or dispersive optomechanical system under the situation that the cavity linewidth ${\ensuremath{\kappa}}_{c}$ is much larger than the mechanical frequency ${\ensuremath{\omega}}_{m}$. We at first show that strong mechanical squeezing beyond the 3-dB limit can be achieved by homodyning the filtered cavity output field in a purely dispersive or purely dissipative optomechanical system for ${\ensuremath{\kappa}}_{c}\ensuremath{\gg}{\ensuremath{\omega}}_{m}$, while the combination of the two kinds of coupling can also effectively enhance the mechanical squeezing. We next show that in these optomechanical systems, mechanical single-phonon states with high fidelity can be generated via photon subtraction on the filtered cavity output field in the regimes of weak optomechanical entanglement and ${\ensuremath{\kappa}}_{c}\ensuremath{\gg}{\ensuremath{\omega}}_{m}$. It is found that the single-phonon Fock state via purely dissipative optomechanical coupling is attainable in the blue-detuned regime, whereas it is present in the red-detuned regime by purely dispersive optomechanical coupling. In addition, the effects of thermal fluctuations on the mechanical squeezing and the negativity of the Wigner function of the mechanical single-phonon states are also studied. It is shown that the Gaussian squeezing is much more robust against decohering thermal fluctuations than the non-Gaussian nonclassicality.

Physical Review A•Apr 16, 2019•16 citations

Quantum-feedback-controlled macroscopic quantum nonlocality in cavity optomechanics

Yaqin Luo, Huatang Tan

Abstract In this paper, we propose a continuous measurement and feedback scheme to achieve strong Einstein–Podolsky–Rosen (EPR) steering and Bell nonlocality of two macroscopic mechanical oscillators in cavity optomechanics. Our system consists of two optomechanical cavities in which two cavity fields are coupled to each other via nondegenerate parametric downconversion. The two cavity output fields are subject to continuous Bell-like homodyne detection and the detection currents are fed back to drive the cavity fields. It is found that when the feedback is absent, the two mechanical oscillators can only be prepared in steady weakly entangled states which however do not display EPR steering and Bell nonlocality, due to the so-called 3 dB limit. But when the feedback is present, it is found that the mechanical entanglement is considerably enhanced such that strong mechanical steering and Bell nonlocality can be obtained in the steady-state regime. We analytically reveal that this is because the feedback drives the mechanical oscillators into a steady approximate two-mode squeezed vacuum state, with arbitrary squeezing in principle. It is shown that the feedback can also obviously improve the purity of the nonclassical mechanical states. The dependences of the mechanical quantum nonlocality on the feedback strength and thermal fluctuations are studied, and it is found that Bell nonlocality is much more vulnerable to thermal noise than EPR steerable nonlocality.

arXiv:2004.01830•Quantum Science and Technology•Sep 17, 2020•10 citations

Strong mechanical squeezing and optomechanical entanglement in a dissipative double-cavity system via pump modulation

Wen-Jie Zhang, Yuchi Zhang, Qi Guo +3 more

We consider a dissipative cavity optomechanical system which couples to an auxiliary cavity with a high-quality factor and is driven by an amplitude-modulated laser field. Due to the introduction of the auxiliary cavity, we find that the steady-state mechanical squeezing can be enhanced compared to the case without an auxiliary cavity and the so-called 3 dB limit can also be broken in the resolved-sideband regime. Moreover, the squeezing can also be achieved even in the unresolved-sideband regime. We study the optomechanical entanglement in the presented system. It is found that the enhanced entanglement can be obtained by introducing the auxiliary cavity, and the entanglement can also be generated in the unresolved-sideband regime for appropriate system parameters. Numerical results show that the presented schemes have strong robustness against the thermal noise acting on the mechanical mode.

Physical Review A•Nov 2, 2021•30 citations

Steady-state light-mechanical quantum steerable correlations in cavity optomechanics

Huatang Tan, Wenwu Deng, Qing-Lin Wu +1 more

Einstein-Podolsky-Rosen (EPR) steering is a quantum nonlocal effect which is intrinsically distinct from Bell nonlocality and quantum entanglement. In this paper, we investigate in detail the properties of steady-state light-mechanical Gaussian steerable correlations in a generic cavity optomechanical system. When considering the steering between the intracavity field and the mechanical oscillator, we find that under blue-detuned driving, the steady-state steering via optomechanical parametric downconversion is present in only one direction and, moreover, the steering direction is determined merely by the relative dissipation strength of the cavity to the mechanics. Furthermore, when considering the steering between the cavity output field and the mechanical oscillator, we reveal that under red-detuned driving, strong steering can be achieved in the sideband-unresolved regime for a filtered output field with given central frequency and bandwidth. This steering with the output field can also be present in one way by adjusting the driving strength and exists up to the environment temperature $T\ensuremath{\approx}10$ K for the parameters close to those in the recent experiments. Finally, we show that the achieved strong light-mechanical correlations can be explored to realize macroscopic EPR steering of two distant optomechanical oscillators in the regime of unresolved sidebands via entanglement swapping.

Physical Review A•May 16, 2017•32 citations

Improving mechanical squeezing in a dissipative optomechanical system with quadratic dispersive coupling

Guolong Li, Xingmin Li, Jun Xin +1 more

Abstract We theoretically investigate that mechanical quantum squeezing in a dissipative optomechanical system, driven by two driving tones, can be improved through quadratic dispersive coupling (QDC) which appears by adjusting a membrane in an appropriate position of an optical cavity. The analytical expressions are derived for revealing the intrinsic mechanism of the mechanical squeezing improvement. Remarkably, compared with the case without QDC, an optimal condition involved the QDC is found to considerably enhance the mechanical squeezing, without reducing the purity of the mechanical squeezed state which even increases at low temperature. We also show that, in this scheme, the mechanical squeezing is still improved by QDC and beyond 3 dB even though the temperature rises. This improvement effect can be reflected by the broader frequency band of the measurable squeezing output field from the cavity. This provides a new opportunity to explore high-precision measurements and quantum nature of macroscopic objects.

New Journal of Physics•Jan 1, 2023•2 citations

Optomechanical squeezing with strong harmonic mechanical driving

Xinyu Lin, Guang-Zheng Ye, Ye Liu +2 more

In this paper, we propose an optomechanical scheme for generating mechanical squeezing over the 3 dB limit, with the mechanical mirror being driven by a strong and linear harmonic force. In contrast to parametric mechanical driving, the linearly driven force shakes the mechanical mirror periodically oscillating at twice the mechanical eigenfrequency with large amplitude, where the mechanical mirror can be dissipatively stabilized by the engineered cavity reservoir to a dynamical squeezed steady state with a maximum degree of squeezing over 8 dB. The mechanical squeezing of more than 3 dB can be achieved even for a mechanical thermal temperature larger than 100 mK. The scheme can be implemented in a cascaded optomechanical setup, with potential applications in engineering continuous variable entanglement and quantum sensing.

Optics Express•Feb 7, 2024•3 citations
In this paper, we first consider the generation of mechanical squeezing in a dispersively or dissipatively coupled optomechanical system by continuously homodyning the output field of the optomechanical cavity. It is found that strong steady-state mechanical squeezing beyond the 3 dB limit can be achieved in both of the optomechanical systems. The properties of the squeezing are quite different for the two types of systems and the reasons for the differences are analyzed. We next consider the achievement of optomechanical steering in the dispersive or dissipative optomechanical system via continuously monitoring the position of the mechanical oscillator. It is revealed that the monitoring can lead the steady-state optomechanical entanglement to be enhanced considerably such that strong steerable correlations can be achieved between the mechanical oscillator and the cavity field. The effects of thermal phonons are studied and it is shown that the generated squeezing and steering are quite robust against the thermal fluctuations.
In this paper, we consider the generation of mechanical squeezed states and single-phonon Fock states, respectively, by homodyne detection and photon subtraction in a dissipative or dispersive optomechanical system under the situation that the cavity linewidth ${\ensuremath{\kappa}}_{c}$ is much larger than the mechanical frequency ${\ensuremath{\omega}}_{m}$. We at first show that strong mechanical squeezing beyond the 3-dB limit can be achieved by homodyning the filtered cavity output field in a purely dispersive or purely dissipative optomechanical system for ${\ensuremath{\kappa}}_{c}\ensuremath{\gg}{\ensuremath{\omega}}_{m}$, while the combination of the two kinds of coupling can also effectively enhance the mechanical squeezing. We next show that in these optomechanical systems, mechanical single-phonon states with high fidelity can be generated via photon subtraction on the filtered cavity output field in the regimes of weak optomechanical entanglement and ${\ensuremath{\kappa}}_{c}\ensuremath{\gg}{\ensuremath{\omega}}_{m}$. It is found that the single-phonon Fock state via purely dissipative optomechanical coupling is attainable in the blue-detuned regime, whereas it is present in the red-detuned regime by purely dispersive optomechanical coupling. In addition, the effects of thermal fluctuations on the mechanical squeezing and the negativity of the Wigner function of the mechanical single-phonon states are also studied. It is shown that the Gaussian squeezing is much more robust against decohering thermal fluctuations than the non-Gaussian nonclassicality.
Abstract In this paper, we propose a continuous measurement and feedback scheme to achieve strong Einstein–Podolsky–Rosen (EPR) steering and Bell nonlocality of two macroscopic mechanical oscillators in cavity optomechanics. Our system consists of two optomechanical cavities in which two cavity fields are coupled to each other via nondegenerate parametric downconversion. The two cavity output fields are subject to continuous Bell-like homodyne detection and the detection currents are fed back to drive the cavity fields. It is found that when the feedback is absent, the two mechanical oscillators can only be prepared in steady weakly entangled states which however do not display EPR steering and Bell nonlocality, due to the so-called 3 dB limit. But when the feedback is present, it is found that the mechanical entanglement is considerably enhanced such that strong mechanical steering and Bell nonlocality can be obtained in the steady-state regime. We analytically reveal that this is because the feedback drives the mechanical oscillators into a steady approximate two-mode squeezed vacuum state, with arbitrary squeezing in principle. It is shown that the feedback can also obviously improve the purity of the nonclassical mechanical states. The dependences of the mechanical quantum nonlocality on the feedback strength and thermal fluctuations are studied, and it is found that Bell nonlocality is much more vulnerable to thermal noise than EPR steerable nonlocality.
We consider a dissipative cavity optomechanical system which couples to an auxiliary cavity with a high-quality factor and is driven by an amplitude-modulated laser field. Due to the introduction of the auxiliary cavity, we find that the steady-state mechanical squeezing can be enhanced compared to the case without an auxiliary cavity and the so-called 3 dB limit can also be broken in the resolved-sideband regime. Moreover, the squeezing can also be achieved even in the unresolved-sideband regime. We study the optomechanical entanglement in the presented system. It is found that the enhanced entanglement can be obtained by introducing the auxiliary cavity, and the entanglement can also be generated in the unresolved-sideband regime for appropriate system parameters. Numerical results show that the presented schemes have strong robustness against the thermal noise acting on the mechanical mode.
Einstein-Podolsky-Rosen (EPR) steering is a quantum nonlocal effect which is intrinsically distinct from Bell nonlocality and quantum entanglement. In this paper, we investigate in detail the properties of steady-state light-mechanical Gaussian steerable correlations in a generic cavity optomechanical system. When considering the steering between the intracavity field and the mechanical oscillator, we find that under blue-detuned driving, the steady-state steering via optomechanical parametric downconversion is present in only one direction and, moreover, the steering direction is determined merely by the relative dissipation strength of the cavity to the mechanics. Furthermore, when considering the steering between the cavity output field and the mechanical oscillator, we reveal that under red-detuned driving, strong steering can be achieved in the sideband-unresolved regime for a filtered output field with given central frequency and bandwidth. This steering with the output field can also be present in one way by adjusting the driving strength and exists up to the environment temperature $T\ensuremath{\approx}10$ K for the parameters close to those in the recent experiments. Finally, we show that the achieved strong light-mechanical correlations can be explored to realize macroscopic EPR steering of two distant optomechanical oscillators in the regime of unresolved sidebands via entanglement swapping.
Abstract We theoretically investigate that mechanical quantum squeezing in a dissipative optomechanical system, driven by two driving tones, can be improved through quadratic dispersive coupling (QDC) which appears by adjusting a membrane in an appropriate position of an optical cavity. The analytical expressions are derived for revealing the intrinsic mechanism of the mechanical squeezing improvement. Remarkably, compared with the case without QDC, an optimal condition involved the QDC is found to considerably enhance the mechanical squeezing, without reducing the purity of the mechanical squeezed state which even increases at low temperature. We also show that, in this scheme, the mechanical squeezing is still improved by QDC and beyond 3 dB even though the temperature rises. This improvement effect can be reflected by the broader frequency band of the measurable squeezing output field from the cavity. This provides a new opportunity to explore high-precision measurements and quantum nature of macroscopic objects.
In this paper, we propose an optomechanical scheme for generating mechanical squeezing over the 3 dB limit, with the mechanical mirror being driven by a strong and linear harmonic force. In contrast to parametric mechanical driving, the linearly driven force shakes the mechanical mirror periodically oscillating at twice the mechanical eigenfrequency with large amplitude, where the mechanical mirror can be dissipatively stabilized by the engineered cavity reservoir to a dynamical squeezed steady state with a maximum degree of squeezing over 8 dB. The mechanical squeezing of more than 3 dB can be achieved even for a mechanical thermal temperature larger than 100 mK. The scheme can be implemented in a cascaded optomechanical setup, with potential applications in engineering continuous variable entanglement and quantum sensing.