EFFECT OF ASYMMETRY IN A BISTABLE SYSTEM WITH QUANTUM FLUCTUATIONS: STRONG FRICTION LIMIT

Abstract

In this paper, we study the effect of asymmetry of the potential in a bistable system with quantum fluctuations. Within the quantum Smoluchowski regime, the expressions for the mean first passage time (MFPT) and signal-to-noise ratio (SNR) of the system are obtained, respectively. Based on the MFPT and SNR, we consider both, the overdamped quantum case and its classical counterpart, the effects of the quantum fluctuations and the asymmetry of the potential on the MFPT and SNR are discussed. Our main results show that (i) the quantum fluctuations facilitate the particle to reach the destination from its original position, (ii) the resonant activation (RA) phenomena can be observed with varying asymmetry of the potential, and (iii) the quantum effects in an asymmetric bistable system about SNR are prominent for lower temperatures and smaller asymmetry of the potential. Moreover, the quantum effects enhance the stochastic resonance (SR) of the system.