Shit Anindita, Chattopadhyay Sudip, Chaudhuri Jyotipratim Ray
Department of Chemistry, Bengal Engineering and Science University, Shibpur, Howrah 711103, India.
Phys Rev E Stat Nonlin Soft Matter Phys. 2012 May;85(5 Pt 1):051102. doi: 10.1103/PhysRevE.85.051102. Epub 2012 May 1.
We explore, in the quantum regime, the stochastic dynamics of a time-periodic, rapidly oscillating potential (having a characteristic frequency of ω) within the framework of a time-dependent system-reservoir Hamiltonian. We invoke the idea of a quantum gauge transformation in light of the standard Floquet theorem in an attempt to construct a Langevin equation (bearing a time-independent effective potential) by employing a systematic perturbative expansion in powers of ω^{-1} using the natural time-scale separation. The time-independent effective potential (corrected to ω^{-2} in leading order) that acts on the slow motion of the driven particle can be employed for trapping. We proceed further to evaluate the rate of escape of the driven particle from the metastable state in the high-temperature limit. We also envisage a resonance phenomena, a true hallmark of the system-reservoir quantization. This development would thus serve as a model template to investigate the trapping mechanism, as well as an appropriate analog to understand the dynamics of a fluctuation-induced escape process from the trap.
在量子体系中,我们在含时系统 - 库哈密顿量框架下,探讨一个具有时间周期性、快速振荡势(特征频率为ω)的随机动力学。鉴于标准弗洛凯定理,我们引入量子规范变换的概念,试图通过利用自然时间尺度分离,以ω⁻¹的幂次进行系统微扰展开来构建一个朗之万方程(带有与时间无关的有效势)。作用于受驱粒子慢运动的与时间无关的有效势(在主导阶修正到ω⁻²)可用于捕获。我们进一步评估在高温极限下受驱粒子从亚稳态逃逸的速率。我们还设想了一种共振现象,这是系统 - 库量子化的一个真正标志。因此,这一进展将作为研究捕获机制的模型模板,以及理解从陷阱中波动诱导逃逸过程动力学的合适类比。