We explore the dynamics of a graphene nanomechanical oscillator coupled to a reference oscillator. Circular graphene drums are forced into self-oscillation, at a frequency fosc, by means of photothermal feedback induced by illuminating the drum with a continuous-wave red laser beam. Synchronization to a reference signal, at a frequency fsync, is achieved by shining a power-modulated blue laser onto the structure. We investigate two regimes of synchronization as a function of both detuning and signal strength for direct (fsync = fosc) and parametric locking (fsync = 2fosc). We detect a regime of phase resonance, where the phase of the oscillator behaves as an underdamped second-order system, with the natural frequency of the phase resonance showing a clear power-law dependence on the locking signal strength. The phase resonance is qualitatively reproduced using a forced van der Pol-Duffing-Mathieu equation.
Dancing Synchronization in Coupled Spin-Torque Nano-Oscillators
我们报道了一种新型的同步，称为舞蹈同步，通过自旋波耦合的两个自旋力矩纳米振荡器（STNO）之间。与已知的两个STNO以各种固定的相对相位锁定的同步不同，在这种新的同步状态下，两个STNO具有相同的频率，但它们的相对相位在公共周期内周期性地变化，从而导致动态波动图案。振荡相对相位的幅度取决于两个STNO的耦合强度以及驱动电流。舞蹈同步是普遍存在的，并且可以存在于两个非线性Van der Pol振子之间的反应性和耗散性耦合。我们的发现为新的功能性STNO设备打开了大门。
