QUANTUM DECOHERENCE IN MIXED QUANTUM-CLASSICAL SYSTEMS - NONADIABATIC PROCESSES
QUANTUM DECOHERENCE IN MIXED QUANTUM-CLASSICAL SYSTEMS - NONADIABATIC PROCESSES
复制标题
DOI：
10.1063/1.470177
复制
发表时间：
1995-11-08
影响因子：
4.4
通讯作者：
ROSSKY, PJ
中科院分区：
文献类型：
--
作者：
BITTNER, ER;ROSSKY, PJ
我们解决混合量子经典模拟中的量子退相干问题。我们证明，将经典路径限制为所有量子路径中的单个路径会影响量子路径的粗粒度。由于与每个量子态相关的各种可能的经典路径发散，这种粗粒度导致量子路径失去相干性。这定义了量子密度矩阵的约简映射，并且我们推导了适合混合量子经典系统的量子主方程。该方程包括两项：第一，由单个经典路径参数化的普通量子刘维尔项；第二，量子退相干项，包括由经典路径的动力学确定的相干时间和长度尺度。以非绝热混合量子经典动力学中电子相干损失的模型计算为例。对于具有非绝热转变的模型电荷转移化学反应，本公式的应用表明，随着退相干时间尺度变短，非绝热性会减弱，并且绝热动力学会在快速退相干的极限下恢复。 (C) 1995 年美国物理研究所。
We address the issue of quantum decoherence in mixed quantum-classical simulations. We demonstrate that restricting the classical paths to a single path among all the quantum paths affects a coarse graining of the quantum paths. Such coarse graining causes the quantum paths to lose coherence as the various possible classical paths associated with each quantum state diverge. This defines a reduction mapping of the quantum density matrix, and we derive a quantum master equation suitable for mixed quantum-classical systems. The equation includes two terms: first, the ordinary quantum Liouvillian which is parametrized by a single classical path, and second, a quantum decoherence term that includes both a coherence time and length scale which are determined by the dynamics of the classical paths. Model calculations for electronic coherence loss in nonadiabatic mixed quantum-classical dynamics are presented as examples. For a model charge transfer chemical reaction with nonadiabatic transitions, application of the present formulation reveals that nonadiabaticity is diminished as the decoherence timescale becomes shorter and adiabatic dynamics are recovered in the limit of rapid decoherence. (C) 1995 American Institute of Physics.