For complex molecules, nuclear degrees of freedom can act as an environment for the electronic “system” variables, allowing the theory and concepts of open quantum systems to be applied. However, when molecular system-environment interactions are non-perturbative and non-Markovian, numerical simulations of the complete system-environment wave function become necessary. These many body dynamics can be very expensive to simulate, and extracting finite-temperature results—which require running and averaging over many such simulations—becomes especially challenging. Here, we present numerical simulations that exploit a recent theoretical result that allows dissipative environmental effects at finite temperature to be extracted efficiently from a single, zero-temperature wave function simulation. Using numerically exact time-dependent variational matrix product states, we verify that this approach can be applied to vibronic tunneling systems and provide insight into the practical problems lurking behind the elegance of the theory, such as the rapidly growing numerical demands that can appear for high temperatures over the length of computations.

对于复杂分子，核自由度可以充当电子“系统”变量的环境，从而允许应用开放量子系统的理论和概念。但是，当分子系统与环境的相互作用为非扰动且为非马尔可夫关系时，则必须对整个系统与环境的波函数进行数值模拟。要模拟这么多人体动力学可能非常昂贵，并且提取有限温度结果（这需要对许多此类模拟进行求平均值）会变得特别具有挑战性。在这里，我们提供了利用最近的理论结果进行的数值模拟，该理论结果允许从单个零温度波函数模拟中有效地提取有限温度下的耗散环境效应。