Nonlinearly induced steady-state photon–phonon entanglement of a dissipative coupled system is studied in the bistable regime. Quantum dynamical characteristics are analysed by solving the mean-field and fluctuation ...Nonlinearly induced steady-state photon–phonon entanglement of a dissipative coupled system is studied in the bistable regime. Quantum dynamical characteristics are analysed by solving the mean-field and fluctuation equations of the system. It is shown that dissipative coupling can induce bistable behaviour for the effective dissipation of the system.Under suitable parameters, one of the steady states significantly reduces the dissipative effect of the system. Consequently,a larger steady-state entanglement can be achieved compared to linear dynamics. Furthermore, the experimental feasibility of the parameters is analysed. Our results provide a new perspective for the implementation of steady-state optomechanical entanglement.展开更多
本文基于一个含有光学参量放大器的腔光力系统,其中腔场和机械场之间具有线性和二次色散耦合的相互作用,研究了二次光力耦合与参量放大器对本征模劈裂的重要影响。通过分析腔场涨落项的输出谱和机械振子位移的涨落谱,得出结论:腔场和机...本文基于一个含有光学参量放大器的腔光力系统,其中腔场和机械场之间具有线性和二次色散耦合的相互作用,研究了二次光力耦合与参量放大器对本征模劈裂的重要影响。通过分析腔场涨落项的输出谱和机械振子位移的涨落谱,得出结论:腔场和机械场均呈现出本征模劈裂的现象,光学参量放大器非线性增益值的大小及二次光力耦合强度均正比于劈裂谱两峰之间的距离,即二者对本征模劈裂效应具有相似的调控作用。本文同时也验证了文献[Journal of Modern Optics,66(5):494–501(2019)]的结论:具有线性和二次耦合的光力系统可以是含有光学参量放大器混合光力系统的一个替代研究平台。展开更多
We theoretically study the effect of the quadratic coupling strength on optomechanical systems subjected to a continuous external force. Quadratic coupling strength originates from strong coupling between the optical ...We theoretically study the effect of the quadratic coupling strength on optomechanical systems subjected to a continuous external force. Quadratic coupling strength originates from strong coupling between the optical and the mechanical degrees of freedom. We show that the quadratic coupling strength reduces the amplitude of the dispersion spectra at the resonance in both blue-and red-sideband regimes. However, it increases(decreases) the amplitude of the absorption spectrum in the blue-(red-)sideband regime. Furthermore, in both sideband regimes, the effective detuning between the pump and the cavity deviates with the quadratic coupling strength. Thereby, appropriate selection of the quadratic coupling strength results in an important magnification(in absolute value) of the group delay for both slow and fast light exiting from the optomechanical cavity.展开更多
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...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 non-reciprocally 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.展开更多
Cavity optomechanical systems provide powerful platforms to manipulate photons and phonons, open potential ap- plications for modern optical communications and precise measurements. With the refrigeration and ground-s...Cavity optomechanical systems provide powerful platforms to manipulate photons and phonons, open potential ap- plications for modern optical communications and precise measurements. With the refrigeration and ground-state cooling technologies, studies of cavity optomechanics are making significant progress towards the quantum regime including non- classical state preparation, quantum state tomography, quantum information processing, and future quantum internet. With further research, it is found that abundant physical phenomena and important applications in both classical and quan- tum regimes appeal as they have a strong optomechanical nonlinearity, which essentially depends on the single-photon optomechanical coupling strength. Thus, engineering the optomechanical interactions and improving the single-photon optomechanical coupling strength become very important subjects. In this article, we first review several mechanisms, theoretically proposed for enhancing optomechanical coupling. Then, we review the experimental progresses on enhancing optomechanical coupling by optimizing its structure and fabrication process. Finally, we review how to use novel structures and materials to enhance the optomechanical coupling strength. The manipulations of the photons and phonons at the level of strong optomechanical coupling are also summarized.展开更多
Cavity magnomechanics has recently become a new platform for studying macroscopic quantum phenomena.The magnetostriction induced vibration mode of a large-size ferromagnet or ferrimagnet reaching its ground state repr...Cavity magnomechanics has recently become a new platform for studying macroscopic quantum phenomena.The magnetostriction induced vibration mode of a large-size ferromagnet or ferrimagnet reaching its ground state represents a genuine macroscopic quantum state.Here we study the ground-state cooling of the mechanical vibration mode in a cavity magnomechanical system,and focus on the role of magnon squeezing in improving the cooling efficiency.The magnon squeezing is obtained by exploiting the magnon self-Kerr nonlinearity.We find that the magnon squeezing can significantly and even completely suppress the magnomechanical Stokes scattering.It thus becomes particularly useful in realizing ground-state cooling in the unresolved-sideband regime,where the conventional sideband cooling protocols become inefficient.We also find that the coupling to the microwave cavity plays only an adverse effect in mechanical cooling.This makes essentially the two-mode magnomechanical system(without involving the microwave cavity)a preferred system for cooling the mechanical motion,in which the magnon mode is established by a uniform bias magnetic field and a microwave drive field.展开更多
Rare-earth ion doped crystals for hybrid quantum technologies are an area of growing interest in the solid-state physics community. We have earlier theoretically proposed a hybrid scheme of a mechanical resonator whic...Rare-earth ion doped crystals for hybrid quantum technologies are an area of growing interest in the solid-state physics community. We have earlier theoretically proposed a hybrid scheme of a mechanical resonator which is fabricated out of a rare-earth doped mono-crystalline structure. The rare-earth ion dopants have absorption energies which are sensitive to crystal strain, and it is thus possible to couple the ions to the bending motion of the crystal cantilever. This type of resonator can be useful for either investigating the laws of quantum physics with material objects or for applications such as sensitive force-sensors. Here, we present the design and fabrication method based on focused-ion-beam etching techniques which we have successfully employed in order to create such microscale resonators, as well as the design of the environment which will allow studying the quantum behavior of the resonators.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant No. 12074206)the Natural Science Foundation of Zhejiang Province of China (Grant No.LY22A040005)supported by the National Natural Science Foundation of China (Grant No. 22103043)。
文摘Nonlinearly induced steady-state photon–phonon entanglement of a dissipative coupled system is studied in the bistable regime. Quantum dynamical characteristics are analysed by solving the mean-field and fluctuation equations of the system. It is shown that dissipative coupling can induce bistable behaviour for the effective dissipation of the system.Under suitable parameters, one of the steady states significantly reduces the dissipative effect of the system. Consequently,a larger steady-state entanglement can be achieved compared to linear dynamics. Furthermore, the experimental feasibility of the parameters is analysed. Our results provide a new perspective for the implementation of steady-state optomechanical entanglement.
文摘本文基于一个含有光学参量放大器的腔光力系统,其中腔场和机械场之间具有线性和二次色散耦合的相互作用,研究了二次光力耦合与参量放大器对本征模劈裂的重要影响。通过分析腔场涨落项的输出谱和机械振子位移的涨落谱,得出结论:腔场和机械场均呈现出本征模劈裂的现象,光学参量放大器非线性增益值的大小及二次光力耦合强度均正比于劈裂谱两峰之间的距离,即二者对本征模劈裂效应具有相似的调控作用。本文同时也验证了文献[Journal of Modern Optics,66(5):494–501(2019)]的结论:具有线性和二次耦合的光力系统可以是含有光学参量放大器混合光力系统的一个替代研究平台。
文摘We theoretically study the effect of the quadratic coupling strength on optomechanical systems subjected to a continuous external force. Quadratic coupling strength originates from strong coupling between the optical and the mechanical degrees of freedom. We show that the quadratic coupling strength reduces the amplitude of the dispersion spectra at the resonance in both blue-and red-sideband regimes. However, it increases(decreases) the amplitude of the absorption spectrum in the blue-(red-)sideband regime. Furthermore, in both sideband regimes, the effective detuning between the pump and the cavity deviates with the quadratic coupling strength. Thereby, appropriate selection of the quadratic coupling strength results in an important magnification(in absolute value) of the group delay for both slow and fast light exiting from the optomechanical cavity.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.12047520,61941501,61775062,11574092,61378012,91121023,62071186 and 61771205).
文摘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 non-reciprocally 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.
基金Project supported by the National Basic Research Program of China(Grant No.2014CB921401)the Tsinghua University Initiative Scientific Research Programthe Tsinghua National Laboratory for Information Science and Technology(TNList)Cross-discipline Foundation
文摘Cavity optomechanical systems provide powerful platforms to manipulate photons and phonons, open potential ap- plications for modern optical communications and precise measurements. With the refrigeration and ground-state cooling technologies, studies of cavity optomechanics are making significant progress towards the quantum regime including non- classical state preparation, quantum state tomography, quantum information processing, and future quantum internet. With further research, it is found that abundant physical phenomena and important applications in both classical and quan- tum regimes appeal as they have a strong optomechanical nonlinearity, which essentially depends on the single-photon optomechanical coupling strength. Thus, engineering the optomechanical interactions and improving the single-photon optomechanical coupling strength become very important subjects. In this article, we first review several mechanisms, theoretically proposed for enhancing optomechanical coupling. Then, we review the experimental progresses on enhancing optomechanical coupling by optimizing its structure and fabrication process. Finally, we review how to use novel structures and materials to enhance the optomechanical coupling strength. The manipulations of the photons and phonons at the level of strong optomechanical coupling are also summarized.
基金supported by Zhejiang Province Program for Science and Technology(2020C01019)the National Natural Science Foundation of China(U1801661,11874249,11934010,12174329).
文摘Cavity magnomechanics has recently become a new platform for studying macroscopic quantum phenomena.The magnetostriction induced vibration mode of a large-size ferromagnet or ferrimagnet reaching its ground state represents a genuine macroscopic quantum state.Here we study the ground-state cooling of the mechanical vibration mode in a cavity magnomechanical system,and focus on the role of magnon squeezing in improving the cooling efficiency.The magnon squeezing is obtained by exploiting the magnon self-Kerr nonlinearity.We find that the magnon squeezing can significantly and even completely suppress the magnomechanical Stokes scattering.It thus becomes particularly useful in realizing ground-state cooling in the unresolved-sideband regime,where the conventional sideband cooling protocols become inefficient.We also find that the coupling to the microwave cavity plays only an adverse effect in mechanical cooling.This makes essentially the two-mode magnomechanical system(without involving the microwave cavity)a preferred system for cooling the mechanical motion,in which the magnon mode is established by a uniform bias magnetic field and a microwave drive field.
基金YLC acknowledges support from the Ville de Paris Emergence Program and from the LABEX Cluster of Excellence FIRST-TF(ANR-10-LABX-48-01),within the Program“investissements d'Avenir”operated by the French National Research Agency(ANR)The project has also received funding from the European Union’Horizon 2020 research and innovation program under grant agreement No 712721(NanOQTech).
文摘Rare-earth ion doped crystals for hybrid quantum technologies are an area of growing interest in the solid-state physics community. We have earlier theoretically proposed a hybrid scheme of a mechanical resonator which is fabricated out of a rare-earth doped mono-crystalline structure. The rare-earth ion dopants have absorption energies which are sensitive to crystal strain, and it is thus possible to couple the ions to the bending motion of the crystal cantilever. This type of resonator can be useful for either investigating the laws of quantum physics with material objects or for applications such as sensitive force-sensors. Here, we present the design and fabrication method based on focused-ion-beam etching techniques which we have successfully employed in order to create such microscale resonators, as well as the design of the environment which will allow studying the quantum behavior of the resonators.