论文标题
混合量子古典半经典动力学中的非线性相关函数和零点能流
Non-Linear Correlation Functions and Zero-Point Energy Flow in Mixed Quantum-Classical Semiclassical Dynamics
论文作者
论文摘要
混合量子经典（MQC）-IVR是一个最近引入的半经典框架，可以选择对复杂系统模式的选择性量化。在量子极限中，MQC再现了半经典的双Herman-kluk IVR结果，可准确捕获核量子相干并保存零点能量。但是，在经典的限制中，而MQC模仿了与线性运算符实时相关函数的HUSIMI-IVR，但即使在零时，非线性相关函数对于非线性相关函数的准确性也明显较小。在这里，我们确定了MQC公式中这种差异的起源，并提出了修改。我们在分析上表明，在时间零时，修改的MQC方法对于所有相关函数都是精确的，在对零点能量（ZPE）流的研究中，我们实际上证明了它正确地获得了作为时间函数的量子和经典限制。有趣的是，虽然经典限制的MQC模拟显示了预期的，非物理ZPE泄漏，但我们发现有可能通过选择性量化系统的选择性量化ZPE流动的方向，而量子限制模式则可以接受能量添加，但可以保留最小量子机械的能量。
Mixed Quantum Classical (MQC)-IVR is a recently introduced semiclassical framework that allows for selective quantization of the modes of a complex system. In the quantum limit, MQC reproduces the semiclassical Double Herman-Kluk IVR results, accurately capturing nuclear quantum coherences and conserving zero-point energy. However, in the classical limit, while MQC mimics the Husimi-IVR for real-time correlation functions with linear operators, it is significantly less accurate for non-linear correlation functions with errors even at time zero. Here, we identify the origin of this discrepancy in the MQC formulation and propose a modification. We analytically show that the modified MQC approach is exact for all correlation functions at time zero, and in a study of zero-point energy (ZPE) flow, we numerically demonstrate that it correctly obtains the quantum and classical limits as a function of time. Interestingly, while classical-limit MQC simulations show the expected, unphysical ZPE leakage, we find it is possible to predict and even modify the direction of ZPE flow through selective quantization of the system, with the quantum-limit modes accepting energy additions but preserving the minimum quantum mechanically required energy.
