论文标题
降低密度基于基质的从头算腔量子电动力学
Reduced-density-matrix-based ab initio cavity quantum electrodynamics
论文作者
论文摘要
开发了一种基于{\ em ab intio}腔量子电动力学（QED）的基于降低密度 - 矩阵（RDM）的方法。 Pauli-Fierz Hamiltonian的期望值以一体和两体的电子和光子RDM表示，并且这些RDM的元素通过半多项式的编程技术直接在多项式时间内优化，而无需了解全波函数。在此过程中得出并执行了重要的合奏$ n $表述条件的QED概括。所得的方法应用于经典地基态强电子相关问题的描述，这通过存在超轻光耦合而增强。首先，我们评估了腔诱导的线性寡乙烯系列的单线 - 三曲线能隙的变化；对于七烯分子，当分子沿空腔模式极化轴对齐时，此差距可以变化多达1.9 kcal mol $^{ - 1} $（或15 \％）。我们还探索了线性氢链中的金属 - 绝缘体过渡，并证明了强烈的电子 - 光子相互作用在所有考虑的耦合强度下都会增加这些系统的绝缘特征。
A reduced-density-matrix (RDM)-based approach to {\em ab initio} cavity quantum electrodynamics (QED) is developed. The expectation value of the Pauli-Fierz Hamiltonian is expressed in terms of one- and two-body electronic and photonic RDMs, and the elements of these RDMs are optimized directly in polynomial time by semidefinite programming techniques, without knowledge of the full wave function. QED generalizations of important ensemble $N$-representability conditions are derived and enforced in this procedure. The resulting approach is applied to the description of classic ground-state strong electron correlation problems, augmented by the presence of ultrastrong light-matter coupling. First, we assess cavity-induced changes to the singlet-triplet energy gap of the linear oligoacene series; for a heptacene molecule, this gap can change by as much as 1.9 kcal mol$^{-1}$ (or 15\%) when the molecule is aligned along the cavity mode polarization axis. We also explore the metal-insulator transition in linear hydrogen chains and demonstrate that strong electron-photon interactions increase the insulating character of these systems under all coupling strengths considered.
