A non-crossing approximation for the study of intersite correlations
A non-crossing approximation for the study of intersite correlations
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用于研究位点间相关性的非交叉近似
DOI：
10.1007/s100510050077
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发表时间：
1999
期刊：
影响因子：
--
通讯作者：
J. Keller
中科院分区：
文献类型：
--
作者：
T. Maier;M. Jarrell;T. Pruschke;J. Keller
针对最近发展起来的动态团簇近似(DCA)中的有效团簇问题，我们提出了一种非交叉近似(NCA)。DCA技术通过将格子问题映射到大小为自洽嵌入的周期性簇上来包括短程相关性。该簇的大小为\Docentclass[12pt]{Minimum}\usepackage{amsath}\usepackage{wa ysym}\usepackage{amsfonts}\usepackage{amssymb}\usepackage{amsbsy}\usepackage{mathsfs}\usepackage{upgreek}\setLength{\oddsidemargin}{-69pt}\Begin{Document}\end{Document}。它是对全格问题的一种完全因果和系统的近似，在两个维度上，修正\Documentclass[12pt]{Minimum}\usepackage{amsath}\usepackage{wa ysym}\usepackage{amsfonts}\usepackage{amsbsy}\usepackage{matrsfs}\usepackage{upgreek}\setlong{\oddsidemarin}{-69pt}\Begin{Document}\end{Document}。我们开发的NCA是一个系统的近似值，其中包含以下更正：\Documentclass[12pt]{minimum}\usepackage{amsath}\usepackage{wa ysym}\usepackage{amsfonts}\usepackage{amssymb}\usepackage{amsbsy}\usepackage{mathsfs}\usepackage{upgreek}\setlong{\oddsidemargin}{-69pt}\Begin{Document}\end{Document}。我们将详细讨论这一方法，并给出Hubbard模型的单粒子性质的结果。在接近半填充的情况下，光谱表现出明显的特征，包括伪隙和由于短程反铁磁关联而产生的非费米液体行为。
We develop a Non-Crossing Approximation (NCA) for the effective cluster problem of the recently developed Dynamical Cluster Approximation (DCA). The DCA technique includes short-ranged correlations by mapping the lattice problem onto a self-consistently embedded periodic cluster of size \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}\end{document}. It is a fully causal and systematic approximation to the full lattice problem, with corrections \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}\end{document} in two dimensions. The NCA we develop is a systematic approximation with corrections \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}\end{document}. The method will be discussed in detail and results for the one-particle properties of the Hubbard model are shown. Near half filling, the spectra display pronounced features including a pseudogap and non-Fermi-liquid behavior due to short-ranged antiferromagnetic correlations.