Department of Chemistry, Chemical Physics Theory Group, University of Toronto, Toronto, Ontario M5S 3H6, Canada.
J Chem Phys. 2010 Feb 21;132(7):074106. doi: 10.1063/1.3310811.
The dynamics of a mixed quantum-classical system, in which the classical subsystem interacts with a dissipative bath, is investigated. This description of the dynamics will be appropriate if the details of the bath dynamics are unimportant but its presence plays an important role in the dissipation of energy to the environment. In this dynamical description, which can be simulated employing an ensemble of stochastic surface-hopping trajectories, the strength of the dissipation is controlled by a friction coefficient. We show that if decoherence, whose effects are controlled by the bath friction, is sufficiently rapid, the equation of motion can be reduced to a master equation. Thus, decoherence and the validity of master equation models may be explored as a function of bath friction. We use this framework to study the mechanism of decoherence in a simple model nonadiabatic chemical reaction.
混合量子-经典系统的动力学研究，其中经典子系统与耗散浴相互作用。如果浴动力学的细节不重要但它的存在在能量向环境的耗散中起着重要作用，那么这种动力学描述是合适的。在这种动力学描述中，可以通过随机表面跳跃轨迹的集合来模拟，耗散的强度由摩擦系数控制。我们表明，如果退相干，其效果由浴摩擦控制，足够快，运动方程可以简化为主方程。因此，可以作为浴摩擦的函数来探索退相干和主方程模型的有效性。我们使用这个框架来研究简单的非绝热化学反应中退相干的机制。
