Quantum escape in the presence of a time-periodic oscillating force
Department of Chemistry, Bengal Engineering and Science University - Shibpur, Howrah-711103, India
2 Department of Physics, Katwa College - Katwa, Burdwan-713130, India
Accepted: 18 January 2012
The stochastic dynamics of a Brownian particle driven by a space-dependent, rapidly oscillating time-periodic potential (with frequency ω) has been addressed in the quantum regime within the framework of time-dependent system-reservoir Hamiltonian. Employing Floquet theorem in conjunction with the idea of separation of time scales, we construct a Langevin equation (containing a static effective potential) by exploiting a systematic perturbative expansion in powers of ω− 1. We compute the escape rate from the meta-stable state using the corresponding quantum Smoluchowski equation and observe a “resonance phenomenon" which is a signature of system-reservoir quantization. This work can be used to model the trapping mechanism as well as the quantum-fluctuation–induced escape process from the trap.
PACS: 05.40.-a – Fluctuation phenomena, random processes, noise, and Brownian motion / 05.40.Jc – Brownian motion / 05.60.Gg – Quantum transport
© EPLA, 2012