Analysis of vibrational resonance in a resistive-capacitor Josephson junction

Abstract

We investigate the effect of direct current (DC) bias, a, on the phenomenon of vibrational resonance (VR) for the washboard potential, linked to a shunted linear resistive-capacitive junction (RCSJ) model of the Josephson junction (JJ). The results showed that the constant DC bias changes the structure of the washboard potential and consequently dictates the slow variable equilibrium dynamics along with parameters of the fast field. The resonant frequency was found to be dependent on bias and the fast excitation measures. Resonances were detected in the response amplitude profile at values of bias for 0 ≤ a < 1, while non-existent at a = 1. The weak frequency domain for VR characterized a monotonically decreasing relationship with bias. The frequency response of the forced system showed increased values at resonance for increments in bias values. Relative to the previous report, the dc bias was found to be instrumental in accelerating the onset of resonances, optimizing frequency response, suppressing and expelling resonances. The numerical results validate the effectiveness of the theoretical analysis. The controlling nature of bias on VR relates a significant avenue of directing applications towards unwanted signal suppression or expulsion and improved frequency character in RCSJ-based systems.