AI 中文总结
研究顺磁莫特绝缘体多体电子结构问题，引入局域退相系综（DE）近似，通过可及局域静态解热系综描述局域电子结构，恢复强关联莫特系统特征，与DMFT定量一致，提供处理顺磁莫特系统的有效途径，揭示强关联与无序物理联系。
AI 中文摘要
解决多体电子结构问题是现代凝聚态物理的核心目标。顺磁莫特绝缘体长期以来对标准方法如密度泛函理论构成挑战。以往解决这些系统要么考虑多体动力学，如动力学平均场理论（DMFT），要么采用由填充静态对称破缺基序的大超胞组成的多晶型描述。受这些观点启发，我们引入局域退相系综（DE）近似，其中通过所有可及局域静态解的热系综描述局域电子结构问题，导致局域电子自能有强烈频率依赖性。我们表明DE能成功恢复强关联莫特系统的标志性特征，在自能以及局域磁矩随时间的持续性方面与DMFT定量一致。通过绕过昂贵的量子蒙特卡罗求解器或大超胞计算，该方法为在第一性原理框架下处理顺磁莫特系统提供了有效途径，突出了强关联物理与无序物理之间更深层次的联系。
英文摘要
Addressing the many-body electronic-structure problem is a central goal of modern condensed-matter physics. Paramagnetic Mott insulators, in particular, have long represented a challenge for standard approaches, such as density-functional theory. Historically, these systems have been tackled either by considering many-body dynamics, as in the case of dynamical mean-field theory (DMFT), or, more recently, by invoking a polymorphous description consisting of large supercells populated with static symmetry-broken motifs whose spatial average restores the paramagnetic state. Inspired by these viewpoints, we introduce the on-site dephased ensemble (DE) approximation, in which the local electronic-structure problem is described by a thermal ensemble of all accessible local static solutions; this gives rise to a strong frequency dependence of the local electronic self-energy, as seen in DMFT or in the coherent-potential approximation of disordered alloys. We show that the DE successfully recovers defining hallmarks of strongly correlated Mott systems, both in terms of the self-energy as well as the persistence of local moments in time, in quantitative agreement with DMFT. By bypassing expensive quantum Monte Carlo solvers or large supercell calculations, this approach offers efficient routes to treating paramagnetic Mott systems in a first-principles setting, and highlights a deeper connection between the physics of strong correlations and that of disorder.
