论文标题
在振动表面滑动的原子力显微镜尖端振荡器模型中摩擦力的估计
Estimation of friction force in an oscillator model of atomic force microscope tip sliding on vibrating surface
论文作者
论文摘要
我们考虑了一个振荡器模型，以描述在周期势描述的表面上驱动的原子力M-croscope（AFM）尖端的定性摩擦力。结果表明，摩擦力的平均值可以通过应用外部时间依赖性周期性扰动来控制。数值模拟表明，取决于扰动的幅度和频率，摩擦的显着下降或增加。观察到了两个不同的振荡方式，它们由扰动的频率和振幅确定。第一个是模式锁定状态，以频率倍数到驱动频率。它发生在谐波扰动和驾驶频率的共鸣。驱动振荡器的另一个运动状态的特征是振荡。在数值实验中观察到了远离振荡器特征频率的大幅度和频率的扰动。在此制度中，振荡器不遵循外部驱动力，而是在振荡器本征和扰动频率相互作用的几种模式下振荡。
We consider an oscillator model to describe qualitatively friction force for an atomic force mi-croscope (AFM) tip driven on a surface described by periodic potential. It is shown that average value of the friction force could be controlled by application of external time-dependent periodic perturbation. Numerical simulation demonstrates significant drop or increase of friction depending on amplitude and frequency of perturbation. Two different oscillating regimes are observed, they determined by frequency and amplitude of perturbation. The first one is regime of mode locking at frequencies multiple to driving frequency. It occurs close to resonance of harmonic perturbation and driving frequencies. Another regime of motion for a driven oscillator is characterized by aperiodic oscillations. It was observed in the numerical experiment for perturbations with large amplitudes and frequencies far from oscillator eigenfrequency. In this regime the oscillator does not follow external driving force, but rather oscillates at several modes which result from interaction of oscillator eigenmode and perturbation frequency.
