The recently developed hybrid magnonics provides new opportunities for advances in both the study of magnetism and the development of quantum information processing.However,engineering coherent quantum state transfer ...The recently developed hybrid magnonics provides new opportunities for advances in both the study of magnetism and the development of quantum information processing.However,engineering coherent quantum state transfer between magnons and specific information carriers,in particular,mechanical oscillators and solid-state spins,remains challenging due to the intrinsically weak interactions and the frequency mismatch between different components.Here,we show how to strongly couple the magnon modes in a nanomagnet to the quantized mechanical motion(phonons)of a micromechanical cantilever in a hybrid tripartite system.The coherent and enhanced magnon-phonon coupling is engineered by introducing the quantum parametric amplification of the mechanical motion.With experimentally feasible parameters,we show that the mechanical parametric drive can be adjusted to drive the system into the strong-coupling regime and even the ultrastrong-coupling regime.Furthermore,we show the coherent state transfer between the nanomagnet and a nitrogen-vacancy center in the dispersive-coupling regime,with the magnon-spin interaction mediated by the virtually-excited squeezed phonons.The amplified mechanical noise can hardly interrupt the coherent dynamics of the system even for low mechanical quality factors,which removes the requirement of applying additional engineered-reservoir techniques.Our work opens up prospects for developing novel quantum transducers,quantum memories and high-precision measurements.展开更多
风电系统的稳定性对电网安全十分重要,提高风电并网的稳定性依然是当今研究的热点所在。针对永磁直驱风电系统的强耦合以及系统投运后网侧、机侧的波动问题。本文首先分析了永磁直驱风电系统的数学模型和暂态特性;然后在电压环引入一阶...风电系统的稳定性对电网安全十分重要,提高风电并网的稳定性依然是当今研究的热点所在。针对永磁直驱风电系统的强耦合以及系统投运后网侧、机侧的波动问题。本文首先分析了永磁直驱风电系统的数学模型和暂态特性;然后在电压环引入一阶线性自抗扰控制器LADRC(linear active disturbance rejection controller),以其代替传统PI控制器;再通过李雅普诺夫理论分析了采用一阶LADRC时系统的稳定性,得出系统在工程意义上是稳定的。最后,在Matlab/Simulink数字平台进行了仿真测试。多工况下的仿真结果表明,该改进方法与PI控制器相比,具有更优的快速性和抗扰性。展开更多
强耦合振子可用于微弱脉冲信号的检测和波形恢复,但其对微弱脉冲信号的检测频率会受到系统内置频率的限制.在系统内置频率固定的情况下,系统只能对一定频率范围内的脉冲信号进行有效检测和波形恢复,在检测更高频率的脉冲信号时会出现波...强耦合振子可用于微弱脉冲信号的检测和波形恢复,但其对微弱脉冲信号的检测频率会受到系统内置频率的限制.在系统内置频率固定的情况下,系统只能对一定频率范围内的脉冲信号进行有效检测和波形恢复,在检测更高频率的脉冲信号时会出现波形失真.本文分析了耦合振子内置频率和微弱脉冲信号检测频率之间的关系,提出两种改进强耦合振子结构以扩展微弱脉冲信号的频率检测范围.通过引入非线性恢复力耦合项,非线性恢复力强耦合振子可以有效保留信号的高频分量,在更高频率的脉冲信号输入时也能较好地保留信号特征.双振子强耦合系统通过引入Van der Pol-Duffing振子,加强了系统内部结构的稳定性,同样达到了扩展脉冲信号频率检测范围的效果.此外,基于变迭代步长和混沌检测的频率相关性,提出了一个未知频率脉冲信号检测方法,以改变迭代步长的方法代替改变系统内置频率来进行频率扫描,并且利用混沌检测的频率相关性,将接收信号和恢复信号的相关系数和纯噪声输入情况下的相关系数进行对比,根据两个相关系数之间的明显差异可以有效检测出脉冲信号.通过仿真实验进行验证,所提方法可以有效检测出未知频率的脉冲信号,并且所提的改进强耦合振子结构相对于强耦合振子有较大的性能提升.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.12205256,12304407,11935006,11774086,122471051217050862)+3 种基金the Henan Provincial Science and Technology Research Project(Grant Nos.232102221001,and 232102210175)the HNQSTIT project(Grant No.2022112)the Fundamental Research Funds for the Central Universities(Grant No.2023FRFK06012)the China Postdoctoral Science Foundation(Grant No.2023TQ0310)。
文摘The recently developed hybrid magnonics provides new opportunities for advances in both the study of magnetism and the development of quantum information processing.However,engineering coherent quantum state transfer between magnons and specific information carriers,in particular,mechanical oscillators and solid-state spins,remains challenging due to the intrinsically weak interactions and the frequency mismatch between different components.Here,we show how to strongly couple the magnon modes in a nanomagnet to the quantized mechanical motion(phonons)of a micromechanical cantilever in a hybrid tripartite system.The coherent and enhanced magnon-phonon coupling is engineered by introducing the quantum parametric amplification of the mechanical motion.With experimentally feasible parameters,we show that the mechanical parametric drive can be adjusted to drive the system into the strong-coupling regime and even the ultrastrong-coupling regime.Furthermore,we show the coherent state transfer between the nanomagnet and a nitrogen-vacancy center in the dispersive-coupling regime,with the magnon-spin interaction mediated by the virtually-excited squeezed phonons.The amplified mechanical noise can hardly interrupt the coherent dynamics of the system even for low mechanical quality factors,which removes the requirement of applying additional engineered-reservoir techniques.Our work opens up prospects for developing novel quantum transducers,quantum memories and high-precision measurements.
基金Project supported by the National Science Foundation of China(10647132)Scientific Research Fundation of Hunan Provincial Education Department,China(10A100)
文摘风电系统的稳定性对电网安全十分重要,提高风电并网的稳定性依然是当今研究的热点所在。针对永磁直驱风电系统的强耦合以及系统投运后网侧、机侧的波动问题。本文首先分析了永磁直驱风电系统的数学模型和暂态特性;然后在电压环引入一阶线性自抗扰控制器LADRC(linear active disturbance rejection controller),以其代替传统PI控制器;再通过李雅普诺夫理论分析了采用一阶LADRC时系统的稳定性,得出系统在工程意义上是稳定的。最后,在Matlab/Simulink数字平台进行了仿真测试。多工况下的仿真结果表明,该改进方法与PI控制器相比,具有更优的快速性和抗扰性。
文摘强耦合振子可用于微弱脉冲信号的检测和波形恢复,但其对微弱脉冲信号的检测频率会受到系统内置频率的限制.在系统内置频率固定的情况下,系统只能对一定频率范围内的脉冲信号进行有效检测和波形恢复,在检测更高频率的脉冲信号时会出现波形失真.本文分析了耦合振子内置频率和微弱脉冲信号检测频率之间的关系,提出两种改进强耦合振子结构以扩展微弱脉冲信号的频率检测范围.通过引入非线性恢复力耦合项,非线性恢复力强耦合振子可以有效保留信号的高频分量,在更高频率的脉冲信号输入时也能较好地保留信号特征.双振子强耦合系统通过引入Van der Pol-Duffing振子,加强了系统内部结构的稳定性,同样达到了扩展脉冲信号频率检测范围的效果.此外,基于变迭代步长和混沌检测的频率相关性,提出了一个未知频率脉冲信号检测方法,以改变迭代步长的方法代替改变系统内置频率来进行频率扫描,并且利用混沌检测的频率相关性,将接收信号和恢复信号的相关系数和纯噪声输入情况下的相关系数进行对比,根据两个相关系数之间的明显差异可以有效检测出脉冲信号.通过仿真实验进行验证,所提方法可以有效检测出未知频率的脉冲信号,并且所提的改进强耦合振子结构相对于强耦合振子有较大的性能提升.
