We investigate theoretically the enhancement of mechanical squeezing in a multimode optomechanical system by introducing a coherent phonon–photon interaction via the backward stimulated Brillouin scattering(BSBS)proc...We investigate theoretically the enhancement of mechanical squeezing in a multimode optomechanical system by introducing a coherent phonon–photon interaction via the backward stimulated Brillouin scattering(BSBS)process.The coherent photon–phonon interaction where two optical modes couple to a Brillouin acoustic mode with a large decay rate provides an extra channel for the cooling of a Duffing mechanical oscillator.The squeezing degree and the robustness to the thermal noises of the Duffing mechanical mode can be enhanced greatly.When the Duffing nonlinearity is weak,the squeezing degree of the mechanical mode in the presence of BSBS can be improved by more than one order of magnitude compared with that in the absence of BSBS.Our scheme may be extended to other quantum systems to study novel quantum effects.展开更多
Quantum entanglement between distant massive mechanical oscillators is an important resource in sensitive measurements and quantum information processing.We achieve the nonreciprocal mechanical entanglement in a compo...Quantum entanglement between distant massive mechanical oscillators is an important resource in sensitive measurements and quantum information processing.We achieve the nonreciprocal mechanical entanglement in a compound optomechanical device consisting of two mechanical oscillators and a spinning whispering-gallery mode(WGM)optical microresonator.It is found that obvious nonreciprocal mechanical entanglement emerges in this system in the presence of the Sagnac effect which is induced by the rotation of the WGM resonator,and the nonreciprocal region can be controlled by tuning the angular velocity of the rotation.The nonreciprocity originates from the breaking of the time-reversal symmetry of this multimode system due to the presence of the Sagnac effect.The optomechanical coupling and the mechanical interaction provide cooling channels for the first and second mechanical oscillators,respectively.Two mechanical oscillators can be cooled simultaneously.The simultaneous cooling and the mechanical coupling of two mechanical oscillators ensure the generation of mechanical entanglement.Furthermore,an optimal mechanical entanglement can be achieved when the moderate optical frequency detuning and the driving power are chosen.The thermal noise of the mechanical environment has a negative effect on mechanical entanglement.Our scheme provides promising opportunities for research of quantum information processing based on phonons and sensitive measurements.展开更多
In this paper,we construct a single-qubit dephasing noise channel based on the nuclear magnetic resonance(NMR)system by employing the bath-engineering technology,and achieve the construction of the tunable non-Markovi...In this paper,we construct a single-qubit dephasing noise channel based on the nuclear magnetic resonance(NMR)system by employing the bath-engineering technology,and achieve the construction of the tunable non-Markovian environment in the dephasing noise channel.Our findings indicate that for the single-qubit system,the transition of system dynamics from Markovian to non-Markovian can be achieved by adjusting the base frequency of the noise power spectrum.However,the base frequency corresponding to this phase transition point is not fixed,and there is a certain relationship between it and the total evolution time of the single-qubit system.Through our research,we discovered a fundamental relationship:if the single-qubit system dynamics undergoe a transition from Markovian to non-Markovian atω_(0) within 0-2t ms,shortening the evolution time to 0-t ms results in an increase of the phase transition point to 2ω_(0).This insight offers crucial guidance for artificially crafting non-Markovian environments across arbitrary time scales in single-qubit systems,and it is not limited by the type of noise.Apart from system dynamics,quantum coherence is also a focal point of our research.We find that when the system dynamics exhibit non-Markovian behavior,the quantum coherence of the single-qubit system experiences revivals.Notably,the timing of these coherence revivals aligns with the instants of the non-Markovianity enhancement.Therefore,our research also serves as a pivotal foundation for the artificial manipulation and realization of quantum coherence revivals within diverse single-qubit systems.展开更多
基金Project supported by the Scientific and Technological Research Program of Chongqing Municipal Education Commission(Grant No.KJQN202400624)the Natural Science Foundation of Chongqing CSTC(Grant No.CSTB2022NSCQBHX0020)+3 种基金the China Electronics Technology Group Corporation 44th Research Institute(Grant No.6310001-2)the Project Grant“Noninvasive Sensing Measurement based on Terahertz Technology”from Province and MOE Collaborative Innovation Centre for New Generation Information Networking and Terminalsthe Key Research Program of CQUPT on Interdisciplinary and Emerging Field(A2018-01)the Venture&Innovation Support program for Chongqing Overseas Returnees Year 2022。
文摘We investigate theoretically the enhancement of mechanical squeezing in a multimode optomechanical system by introducing a coherent phonon–photon interaction via the backward stimulated Brillouin scattering(BSBS)process.The coherent photon–phonon interaction where two optical modes couple to a Brillouin acoustic mode with a large decay rate provides an extra channel for the cooling of a Duffing mechanical oscillator.The squeezing degree and the robustness to the thermal noises of the Duffing mechanical mode can be enhanced greatly.When the Duffing nonlinearity is weak,the squeezing degree of the mechanical mode in the presence of BSBS can be improved by more than one order of magnitude compared with that in the absence of BSBS.Our scheme may be extended to other quantum systems to study novel quantum effects.
基金supported by the Scientific and Technological Research Program of Chongqing Municipal Education Commission(Grant No.KJQN202400624)the Natural Science Foundation of Chongqing CSTC(Grant No.CSTB2022NSCQ-BHX0020).
文摘Quantum entanglement between distant massive mechanical oscillators is an important resource in sensitive measurements and quantum information processing.We achieve the nonreciprocal mechanical entanglement in a compound optomechanical device consisting of two mechanical oscillators and a spinning whispering-gallery mode(WGM)optical microresonator.It is found that obvious nonreciprocal mechanical entanglement emerges in this system in the presence of the Sagnac effect which is induced by the rotation of the WGM resonator,and the nonreciprocal region can be controlled by tuning the angular velocity of the rotation.The nonreciprocity originates from the breaking of the time-reversal symmetry of this multimode system due to the presence of the Sagnac effect.The optomechanical coupling and the mechanical interaction provide cooling channels for the first and second mechanical oscillators,respectively.Two mechanical oscillators can be cooled simultaneously.The simultaneous cooling and the mechanical coupling of two mechanical oscillators ensure the generation of mechanical entanglement.Furthermore,an optimal mechanical entanglement can be achieved when the moderate optical frequency detuning and the driving power are chosen.The thermal noise of the mechanical environment has a negative effect on mechanical entanglement.Our scheme provides promising opportunities for research of quantum information processing based on phonons and sensitive measurements.
基金supported by Science and Technology Research Program of Chongqing Municipal Education Commission(Grant No.KJQN202200603)the National Natural Science Foundation of China(Grant No.62205042)+1 种基金the Program for the Innovative Talents of Postdoctor of Chongqing(Grant No.2209013344731596)the Chongqing University of Posts and Telecommunications(Grant Nos.A2022-304,A2022-288,and A2024196)。
文摘In this paper,we construct a single-qubit dephasing noise channel based on the nuclear magnetic resonance(NMR)system by employing the bath-engineering technology,and achieve the construction of the tunable non-Markovian environment in the dephasing noise channel.Our findings indicate that for the single-qubit system,the transition of system dynamics from Markovian to non-Markovian can be achieved by adjusting the base frequency of the noise power spectrum.However,the base frequency corresponding to this phase transition point is not fixed,and there is a certain relationship between it and the total evolution time of the single-qubit system.Through our research,we discovered a fundamental relationship:if the single-qubit system dynamics undergoe a transition from Markovian to non-Markovian atω_(0) within 0-2t ms,shortening the evolution time to 0-t ms results in an increase of the phase transition point to 2ω_(0).This insight offers crucial guidance for artificially crafting non-Markovian environments across arbitrary time scales in single-qubit systems,and it is not limited by the type of noise.Apart from system dynamics,quantum coherence is also a focal point of our research.We find that when the system dynamics exhibit non-Markovian behavior,the quantum coherence of the single-qubit system experiences revivals.Notably,the timing of these coherence revivals aligns with the instants of the non-Markovianity enhancement.Therefore,our research also serves as a pivotal foundation for the artificial manipulation and realization of quantum coherence revivals within diverse single-qubit systems.
