理解平均场半经典轻物质动力学的本质：能量转移、电子-电子关联、外部驱动和长时间细致平衡的研究
Understanding the Nature of Mean-Field Semiclassical Light-Matter Dynamics: An Investigation of Energy Transfer, Electron-Electron Correlations, External Driving and Long-Time Detailed Balance
摘要：
半经典电动力学是研究光-物质相互作用的一种有效方法，特别是对于现实分子系统。然而，没有唯一的半经典方案。一方面，分子间的相互作用可以用连接不同分子的静态两体相互作用加上一个经典的横向电场来瞬时描述;我们称之为哈密顿量#I。另一方面，分子间相互作用也可以描述为完全通过经典的单体电场介导的效应，而没有任何量子效应（假设我们忽略电子交换）;我们将其称为哈密顿量II。此外，人们也可以将这两个哈密顿量混合成第三个混合哈密顿量，它保留了较低激发的量子电子-电子相关性，但以平均场的方式描述了较高的激发。为了研究哪种半经典方案在实际应用中是最可靠的，在这里我们研究了一对相同的两能级系统（TLS）的实时动力学，该系统经历共振能量转移（RET）或集体驱动动力学。虽然所有的方法都表现得相当不错，当没有强烈的外部激励，我们发现，没有一个单一的方法是完美的所有条件。每一种方法都有其独特的问题：哈密顿函数I在RET中表现最好，但在驱动动力学中表现得很复杂。哈密顿量II总是稳定的，但在短距离的RET中显然不稳定。一个关键的发现是，在外部驱动下，哈密顿量I的全组态相互作用描述强烈高估了长时间的电子能量，突出了一个不明显的事实，即如果计划将量子分子与经典光合并，则电子-电子相关性的完整精确处理实际上会导致比简单的平均场处理更糟糕的结果。
英文摘要：
Semiclassical electrodynamics is an appealing approach for studying light-matter interactions, especially for realistic molecular systems. However, there is no unique semiclassical scheme. On the one hand, intermolecular interactions can be described instantaneously by static two-body interactions connecting different molecules plus a classical transverse E-field; we will call this Hamiltonian #I. On the other hand, intermolecular interactions can also be described as effects that are mediated exclusively through a classical one-body E-field without any quantum effects at all (assuming we ignore electronic exchange); we will call this Hamiltonian #II. Moreover, one can also mix these two Hamiltonians into a third, hybrid Hamiltonian, which preserves quantum electron-electron correlations for lower excitations but describes higher excitations in a mean-field way. To investigate which semiclassical scheme is most reliable for practical use, here we study the real-time dynamics of a pair of identical two-level systems (TLSs) undergoing either resonance energy transfer (RET) or collectively driven dynamics. While all approaches perform reasonably well when there is no strong external excitation, we find that no single approach is perfect for all conditions. Each method has its own distinct problems: Hamiltonian #I performs best for RET but behaves in a complicated manner for driven dynamics. Hamiltonian #II is always stable, but obviously fails for RET at short distances. One key finding is that, under externally driving, a full configuration interaction description of Hamiltonian #I strongly overestimates the long-time electronic energy, highlighting the not obvious fact that, if one plans to merge quantum molecules with classical light, a full, exact treatment of electron-electron correlations can actually lead to worse results than a simple mean-field treatment.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
