Finite-temperature dynamics of singlet fission in crystalline rubrene is investigated by utilizing the Dirac–Frenkel time-dependent variational method in combination with multiple Davydov D₂ trial states. To probe temperature effects on the singlet fission process mediated by a conical intersection, the variational method is extended to include number state propagation with thermally averaged Boltzmann distribution as initialization. This allows us to simulate two-dimensional electronic spectroscopic signals of two-mode and three-mode models of crystalline rubrene in the temperature range from 0 K to 300 K. It is demonstrated that an elevated temperature facilitates excitonic population transfer and accelerates the singlet fission process. In addition, increasing temperature leads to dramatic changes in two-dimensional spectra, thanks to temperature-dependent electronic dephasing and to an increased number of system eigenstates amenable to spectroscopic probing.

中文翻译：

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温度对锥形相交介导的单重态裂变动力学的影响

利用狄拉克-弗伦克时间相关变分方法结合多个Davydov D ₂来研究晶体红荧烯中单线态裂变的有限温度动力学试用状态。为了探究温度对圆锥形相交介导的单线态裂变过程的影响，扩展了变分方法，使其包括具有热平均玻尔兹曼分布的数态传播作为初始化。这使我们能够在0 K至300 K的温度范围内模拟晶体红荧烯的二模和三模模型的二维电子光谱信号。事实证明，升高的温度会促进激子的人口转移并加速单线态裂变处理。另外，由于温度相关的电子移相以及适用于光谱探测的系统本征态数量的增加，温度升高会导致二维光谱发生剧烈变化。