Vibrational resonance in a harmonically trapped potential system

We report our investigation of role of shape of a harmonically trapped potential system driven by a biharmonic external force with two widely different frequencies ω and Ω with Ω ≫ ω on vibrational resonance. The potential is capable of generating odd number of potential wells depending upon the values of the parameters in the potential function. Applying a theoretical approach we obtain an analytical expression for the response amplitude Q at the low-frequency ω. The response amplitude exhibits multiple peaks and approaches a non-zero limiting value when the amplitude of the high-frequency force is varied. We explain the mechanism of observed resonance dynamics. We bringout the effect of number of potential wells on the resonance behaviour.