AI 中文总结
该研究针对生物分子链有限片段内单个激发的迁移，结合非绝热极化子模型与量子行走类比，揭示初始位置、边界条件对概率分布及量子输运的关键影响。
AI 中文摘要
我们研究在长生物分子链的一部分——有限分子片段的结构单元处激发的单个激发的迁移。该激发无法离开该片段，且与晶格的热振动局域耦合，形成对应于非绝热极化子的自陷态。我们计算了在片段节点处找到该激发的随时间变化的概率分布，特别关注初始激发位置的作用。观察到本模型与具有反射边界的有限链上的连续时间量子行走模型存在形式上的类比。结果显示，相对于初始激发位置对称放置的节点，其概率分布存在不对称性，这种不对称性完全源于初始激发在有限片段内的不对称放置。唯一的例外是当初始激发节点位于片段中心时，概率分布变为对称。复杂的干涉图案以及缺乏明确定义的复兴，源于模式频率的非等距频谱，导致组成模式发生渐进退相。因此，初始时良好局域化的概率最大值分裂为一个主导最大值，伴随几个强度较低的次级最大值。这些发现强调了边界条件和初始态几何在控制有限分子系统中量子输运方面的重要性。
英文摘要
We study the migration of a single excitation excited at a structural element of a finite molecular segment, which is a part of a long biomolecular chain. The excitation cannot leave the segment and is locally coupled to thermal vibrations of the lattice, forming a self-trapped state corresponding to a nonadiabatic polaron. The time-dependent probability distribution of finding the excitation at the nodes of the segment is calculated, with particular emphasis on the role of the initial excitation position. A formal analogy is observed between the present model and continuous-time quantum walk models on finite chains with reflecting boundaries. The results reveal an asymmetry in the probability distribution for nodes symmetrically positioned with respect to the initially excited site, which arises solely from the asymmetric placement of the initial excitation within the finite segment. The only exception occurs when the initially excited node is located at the center of the segment, where the probability distribution becomes symmetric. The complex interference pattern and the absence of well-defined revivals stem from the non-equidistant spectrum of mode frequencies, leading to progressive dephasing of the constituent modes. As a result, the initially well-localized probability maximum fragments into one dominant maximum accompanied by several secondary maxima of lower intensity. These findings highlight the importance of boundary conditions and initial-state geometry in controlling quantum transport in finite molecular systems.
