Stochastic resonance in overdamped two coupled anharmonic oscillators
Stochastic resonance in overdamped two coupled anharmonic oscillators
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DOI：
10.1016/j.physa.2004.08.081
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发表时间：
2005-03
影响因子：
3.3
通讯作者：
V. M. Gandhimathi;K. Murali;S. Rajasekar
中科院分区：
文献类型：
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作者：
V. M. Gandhimathi;K. Murali;S. Rajasekar
我们考虑了两个耦合的非简谐振子的过阻尼型，在系统的两个状态变量中的一个添加了外加周期作用力Fsinωt和高斯噪声项η(T)。在没有外加周期性外力和噪声的情况下进行了线性稳定性分析。然后，研究了仅含周期外力和仅含噪声项的系统。在无噪声系统中，发现四个周期-T轨道共存，对于其他参数的固定值，对于较小的强迫幅度f，每四个井中一个周期-T轨道。当f，fc达到临界值时，出现井间周期轨道。FCI随耦合强度δ的增大而增大。在没有强迫的情况下，发现系统在噪声强度D，DC的特定值以上的两个井之间呈现出间歇性跳跃运动。噪声引起的跳跃行为以首次通过时间和停留时间分布为特征。其次，数值研究了周期外力作用下噪声的影响。发现该系统具有随机共振行为。用功率谱、信噪比和驻留时间分布表征了观测到的随机共振动力学。最大Lyapunov指数与噪声强度的关系曲线呈随机共振分布。通过改变强迫频率ω和耦合强度δ研究了随机共振的发生。最后，给出了外加周期性外力和噪声项对不同状态变量的影响。
We consider the overdamped version of two coupled anharmonic oscillators with the external periodic force fsinωt and Gaussian noise term η(t) added to one of the two state variables of the system. Linear stability analysis is carried out in the absence of external periodic force and noise. Then, the system with external periodic force only and noise term only are studied. In the noise free system, four period-T orbits are found to co-exist, one in each of the four wells for small values of forcing amplitude f for fixed values of other parameters. At a critical value of f, fc, cross-well periodic orbit appears. fcis found to increase with increase in the coupling strength δ. In the absence of forcing, the system is found to exhibit intermittent jumping motion between two wells above a particular value of noise strength D, Dc. The noise-induced jumping behaviour is characterized by first-passage time and residence time distributions. Next, the influence of noise in the presence of the external periodic force is numerically studied. The system is found to exhibit stochastic resonance behaviour. The observed stochastic resonance dynamics is characterized using power spectrum, signal-to-noise ratio and residence time distribution. The plot of maximal Lyapunov exponent versus noise strength has shown a stochastic resonance profile. The occurrence of stochastic resonance is studied by varying the forcing frequency ω and the coupling strength δ. Finally, the influence of addition of external periodic force and noise term to different state variables is also presented.