We present a numerical investigation of the tunneling dynamics of a particle moving in a bistable potential with fluctuating barrier which is coupled to a non-integrable classical system and study the interplay between classical chaos and barrier fluctuation in the tunneling dynamics. We found that the coupling of the quantum system with the classical subsystem decreases the tunneling rate irrespective of whether the classical subsystem is regular or chaotic and also irrespective of the fact that whether the barrier fluctuates or not. Presence of classical chaos always enhances the tunneling rate constant. The effect of barrier fluctuation on the tunneling rate in a mixed quantum-classical system is to suppress the tunneling rate. In contrast to the case of regular subsystem, the suppression arising due to barrier fluctuation is more visible when the subsystem is chaotic.

In this paper, we have investigated the dynamics of a damped harmonic oscillator in the presence of an electromagnetic field. Magnetic field may induce asymmetric splitting of the spectrum of the output signal withtwo peaks in the case of a driven damped two-dimensional harmonic oscillator. One more additional peak may appear for the three-dimensional case. At the same time, one may observe an antiresonance phenomenon even for the driven damped cyclotron motion where the system with the purely non-conservative force fields is driven by an electric field. Finally, our calculation exhibits how the magnetic field can modulate the frequency of a harmonic oscillator, the phase difference (between the input and the output signals) and the efficiency like quantity of the energy storing process, respectively. Thus, the present study might be applicable in areas related to refractive index,the barrier crossing dynamics and autonomous stochastic resonance, respectively.