Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.
School of Chemistry, Tel Aviv University, Tel Aviv 69978, Israel.
J Chem Phys. 2023 Apr 28;158(16). doi: 10.1063/5.0147359.
As in the case of a free particle, the initial growth of a broad (relative to lattice spacing) wavepacket placed on an ordered lattice is slow (its time derivative has zero initial slope), and the spread (root mean square displacement) becomes linear in t at a long time. On a disordered lattice, the growth is inhibited for a long time (Anderson localization). We consider site disorder with nearest-neighbor hopping on one- and two-dimensional systems and show via numerical simulations supported by the analytical study that the short time growth of the particle distribution is faster on the disordered lattice than on the ordered one. Such faster spread takes place on time and length scales that may be relevant to the exciton motion in disordered systems.
与自由粒子的情况一样，在有序晶格上放置的宽（相对于晶格间距）波包的初始增长缓慢（其时间导数的初始斜率为零），并且在长时间后扩展（均方根位移）呈线性。在无序晶格上，长时间的增长受到抑制（安德森局域化）。我们考虑具有最近邻跃迁的点和二维系统中的无序，通过数值模拟和分析研究表明，在无序晶格上的粒子分布的短时间增长比在有序晶格上快。这种更快的扩展发生在可能与无序系统中的激子运动相关的时间和长度尺度上。
