论文标题
变分离散行动理论
Variational Discrete Action Theory
论文作者
论文摘要
在这里，我们提出了变分离散作用理论（VDAT）来研究量子多体汉密尔顿人的基态特性。 VDAT是一种基于顺序产物密度矩阵（SPD）ANSATZ的变异理论，其特征在于整数$ \ Mathcal {n} $，它单调地接近精确解决方案，并增加了$ \ Mathcal {n} $。为了评估SPD，我们引入了离散的动作和相应的整数绿色功能。我们使用VDAT准确评估了两个相互作用电子的规范模型：Anderson杂质模型（AIM）和$ d = \ infty $ hubbard模型。 For the latter, we evaluate $\mathcal{N}=2-4$, where $\mathcal{N}=2$ recovers the Gutzwiller approximation (GA), and we show that $\mathcal{N}=3$, which exactly evaluates the Gutzwiller-Baeriswyl wave function, provides a truly minimal yet precise description of Mott physics with a cost similar to the GA。 VDAT是一种灵活的理论，用于研究量子汉密尔顿人，既可以使用最先进的方法和简单，有效的方法在一个框架中进行竞争。
Here we propose the Variational Discrete Action Theory (VDAT) to study the ground state properties of quantum many-body Hamiltonians. VDAT is a variational theory based on the sequential product density matrix (SPD) ansatz, characterized by an integer $\mathcal{N}$, which monotonically approaches the exact solution with increasing $\mathcal{N}$. To evaluate the SPD, we introduce a discrete action and a corresponding integer time Green's function. We use VDAT to exactly evaluate the SPD in two canonical models of interacting electrons: the Anderson impurity model (AIM) and the $d=\infty$ Hubbard model. For the latter, we evaluate $\mathcal{N}=2-4$, where $\mathcal{N}=2$ recovers the Gutzwiller approximation (GA), and we show that $\mathcal{N}=3$, which exactly evaluates the Gutzwiller-Baeriswyl wave function, provides a truly minimal yet precise description of Mott physics with a cost similar to the GA. VDAT is a flexible theory for studying quantum Hamiltonians, competing both with state-of-the-art methods and simple, efficient approaches all within a single framework.
