磁力系统中磁振子频梳的产生与调控

GENERATION AND CONTROL OF MAGNONIC FREQUENCY COMBS IN THE MAGNOMECHANICAL SYSTEM

磁振子频梳包含一系列离散的、等间距的频率成分,在高精密频率测量方面有重要的应用。本文研究了磁力系统中磁振子频梳的产生和调控,利用龙格-库塔法数值求解系统的海森堡-朗之万方程得到系统的动力学演化,然后做快速傅里叶变换,得到磁振子的频谱图。研究发现在较强的驱动下,磁致伸缩效应诱导的磁力非线性会导致频谱图中出现二阶、三阶甚至更高阶边带的频率成分。微波驱动强度增大时,高阶边带频谱的阶数会增多,同时各阶边带振幅会变大,平台区也会随着驱动的增加而变宽。研究结果有助于理解非线性磁振子动力学,并且提供了一个实现微波频率精密测量的方案。

Magnonic frequency combs consist of a set of discrete and equally spaced frequencies,which play an important role in high-precision frequency measurement.In this paper,the generation and control of magnonic frequency combs in the magnomechanical system is studied.Using the Runge-Kuta method to numerically solve the Heisenberg-Langevin equation to obtain the dynamic evolution of the system,and making the fast fourier transform to achieve the magnonic spectrum.Under a strong microwave drive field,the magnetostrictive interaction induced magnomechanical nonlinearity can lead to second-order,third-order or even high-order sideband components in the spectrum.When the intensity of the microwave drive field increases,the number of orders of the high-order sidebands spectrum increases and the amplitude of each sideband becomes larger.The plateau region becomes wider as the intensity of the microwave drive field increases.The results are beneficial for the understanding of nonlinear magnonic dynamics,and provide a promising route for high-precision microwave frequency metrology.