Dipartimento di Fisica Universitá degli Studi di Trento, Via Sommarive 14, Povo (Trento), I-38050 Italy.
J Chem Phys. 2012 Jun 7;136(21):214111. doi: 10.1063/1.4722213.
We study the dynamics of quantum excitations inside macromolecules which can undergo conformational transitions. In the first part of the paper, we use the path integral formalism to rigorously derive a set of coupled equations of motion which simultaneously describe the molecular and quantum transport dynamics, and obey the fluctuation/dissipation relationship. We also introduce an algorithm which yields the most probable molecular and quantum transport pathways in rare, thermally activated reactions. In the second part of the paper, we apply this formalism to simulate the propagation of a quantum charge during the collapse of a polymer from an initial stretched conformation to a final globular state. We find that the charge dynamics is quenched when the chain reaches a molten globule state. Using random matrix theory we show that this transition is due to an increase of quantum localization driven by dynamical disorder. We argue that collapsing conducting polymers may represent a physical realization of quantum small-world networks with dynamical rewiring probability.
我们研究了能够经历构象转变的大分子内部量子激发的动力学。在论文的第一部分，我们使用路径积分形式主义严格推导出一组耦合运动方程，这些方程同时描述了分子和量子输运动力学，并服从涨落耗散关系。我们还引入了一种算法，该算法可以在罕见的热激活反应中得出最可能的分子和量子输运途径。在论文的第二部分，我们将这一形式主义应用于模拟量子电荷在聚合物从初始拉伸构象坍缩到最终球状状态过程中的传播。我们发现当链达到无规线团状态时，电荷动力学被猝灭。我们使用随机矩阵理论表明，这种转变是由动力学无序驱动的量子局域化的增加引起的。我们认为，坍缩的导电聚合物可能代表了具有动态重连概率的量子小世界网络的物理实现。
