论文标题
相互作用与随机性在光诱导的二聚体晶格上电荷振荡同步的竞争
Competition between Interactions and Randomness in Photoinduced Synchronization of Charge Oscillations on a Dimer Lattice
论文作者
论文摘要
从二聚体晶格上的电子呼吸模式出现，从相互作用与随机性之间的竞争的角度研究了通过电子呼吸模式在二聚体晶格上的出现实现的光激发振荡的同步。我们在简单的二聚体晶格上采用了扩展的哈伯德模型，并在最近邻居站点之间的所有传输积分中添加随机数。通过精确的对角线化方法，使用时间依赖性的Schrödinger方程计算光诱导的动力学。尽管在光激发期间和之后，随机性倾向于对不同键的电荷振荡不同步，但在强烈的光激发后的某个时间内，有足够强的现场排斥力$ U $克服了这种效果，并同步了这些电荷振荡。使用从所有键上当前密度的时间曲线得出的顺序参数评估同步度。至于最近的邻居交互$ v $，如果$ v $较弱的吸引力，则可以通过促进电荷振荡来增加订单参数。这些发现与先前报道的有机导体$κ$ - （bis [ethylenedithio] tetrathiafulvalene）$ _ 2 $ cu [n（cn）$ _ 2 $] BR的相关性。
The synchronization of charge oscillations after photoexcitation that has been realized through the emergence of an electronic breathing mode on dimer lattices is studied here from the viewpoint of the competition between interactions and randomness. We employ an extended Hubbard model at three-quarter filling on a simple dimer lattice and add random numbers to all transfer integrals between nearest-neighbor sites. Photoinduced dynamics are calculated using the time-dependent Schrödinger equation by the exact diagonalization method. Although the randomness tends to unsynchronize charge oscillations on different bonds during and after photoexcitation, sufficiently strong on-site repulsion $U$ overcomes this effect and synchronizes these charge oscillations some time after strong photoexcitation. The degree of synchronization is evaluated using an order parameter that is derived from the time profiles of the current densities on all bonds. As to the nearest-neighbor interaction $V$, if $V$ is weakly attractive, it increases the order parameter by facilitating the charge oscillations. The relevance of these findings to previously reported experimental and theoretical results for the organic conductor $κ$-(bis[ethylenedithio]tetrathiafulvalene)$_2$Cu[N(CN)$_2$]Br is discussed.
