Nonlocal correlation effects in fermionic many-body systems: Overcoming the noncausality problem
Nonlocal correlation effects in fermionic many-body systems: Overcoming the noncausality problem
复制标题
费米多体系统中的非局域相关效应：克服非因果问题
DOI：
10.1103/physrevb.105.245115
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发表时间：
2020
影响因子：
3.7
通讯作者：
S. Biermann
中科院分区：
文献类型：
--
作者：
S. Backes;Jae;S. Biermann
受准二维费米子系统（如高温超导氧化物、层状过渡金属硫族化物或表面或界面系统）的有趣物理特性的激励，面向包括局域和非局域电子相关的多体计算方法的发展已成为一个快速发展的领域。然而，人们已经认识到，这些方法的成功可能会受到有关有效量或可观察量中出现的非因果特征的阻碍。在这里，我们提出了一种将局部多体技术如动态平均场理论（DMFT）扩展到非局部相关的新方法，它保留了因果关系并具有物理上的直观解释。我们的策略对dmft启发的一般类型的多体方法具有启示意义，并且可以以最小的努力适应于簇，双玻色子或双费米子技术。
Motivated by the intriguing physics of quasi-2d fermionic systems, such as high-temperature superconducting oxides, layered transition metal chalcogenides or surface or interface systems, the development of many-body computational methods geared at including both local and non-local electronic correlations has become a rapidly evolving field. It has been realized, however, that the success of such methods can be hampered by the emergence of noncausal features in the effective or observable quantities involved. Here, we present a new approach of extending local many-body techniques such as dynamical mean field theory (DMFT) to nonlocal correlations, which preserves causality and has a physically intuitive interpretation. Our strategy has implications for the general class of DMFT-inspired many-body methods, and can be adapted to cluster, dual boson or dual fermion techniques with minimal effort.