论文标题
分子晶体中激子转运的理论与腔密切耦合：一种依赖温度的变化方法
Theory of exciton transport in molecular crystals strongly coupled to a cavity: A temperature-dependent variational approach
论文作者
论文摘要
我们提出了一种在有机分子晶体中与单个空腔模式强烈相互作用的激子转运的半分析理论。基于荷斯坦 - 塔维斯 - 卡明模型和库拜公式，我们在温度依赖性变分的规范变换的框架中得出了激子迁移率的表达，该框架可以涵盖各种激子振动耦合，激子型腔体耦合耦合和温度。总迁移率的相干部分的封闭式表达是在激子振动耦合的零点中获得的，这证明了振动穿着的深色激子在确定传输机制中的重要性。通过对H型和J聚集的数值模拟，我们发现激动子腔耦合对总迁移率具有重大影响：1）在低温下，存在最佳的兴奋性伴侣耦合强度，可以使H-聚集物达到最大的流动性，同时又有j-aggiention-cromition necronity在j-aggiential in j-aggiential in grignition in j-aggrigation in j-aggigriential ndive n oby intimention j-aggregity new secrominity n oprigon new sigriention j-aggrigation in耦合； 2）在高温下，两种类型的聚集体的迁移率都被腔增强。我们说明了上述低温最佳迁移率在室温下使用逼真的参数在H-聚集体中观察到的最佳迁移率。
We present a semianalytical theory for exciton transport in organic molecular crystals interacting strongly with a single cavity mode. Based on the Holstein-Tavis-Cummings model and the Kubo formula, we derive an exciton mobility expression in the framework of a temperature-dependent variational canonical transformation, which can cover a wide range of exciton-vibration coupling, exciton-cavity coupling, and temperatures. A closed-form expression for the coherent part of the total mobility is obtained in the zeroth order of the exciton-vibration coupling, which demonstrates the significance of vibrationally dressed dark excitons in the determination of the transport mechanism. By performing numerical simulations on both the H- and J-aggregates, we find that the exciton-cavity coupling has significant effects on the total mobility: 1) At low temperatures, there exists an optimal exciton-cavity coupling strength for the H-aggregate at which a maximal mobility is reached, while the mobility in the J-aggregate decreases monotonically with increasing exciton-cavity coupling; 2) At high temperatures, the mobility in both types of aggregates get enhanced by the cavity. We illustrate the above-mentioned low-temperature optimal mobility observed in the H-aggregate by using realistic parameters at room temperature.
