Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden, Germany and Max Planck Institute for the Physics of Complex Systems, Nöthnitzer Straße 38, 01187 Dresden, Germany and Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, USA.
Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, USA.
Phys Rev Lett. 2014 Jun 6;112(22):226401. doi: 10.1103/PhysRevLett.112.226401. Epub 2014 Jun 4.
Self-consistent dynamical approximations for strongly correlated fermion systems are particularly successful in capturing the dynamical competition of local correlations. In these, the effect of spatially extended degrees of freedom is usually only taken into account in a mean field fashion or as a secondary effect. As a result, critical exponents associated with phase transitions have a mean field character. Here we demonstrate that diagrammatic multiscale methods anchored around local approximations are indeed capable of capturing the non-mean-field nature of the critical point of the lattice model encoded in a nonvanishing anomalous dimension and of correctly describing the transition to mean-field-like behavior as the number of spatial dimensions increases.
自洽动力学近似在捕捉强关联费米子系统的局域相关动力学竞争方面特别成功。在这些近似中，空间扩展自由度的影响通常仅以平均场方式或作为次要效应考虑。因此，与相变相关的临界指数具有平均场特征。在这里，我们证明了以局域近似为基础的图表多尺度方法确实能够捕捉到晶格模型中临界点的非平均场性质，通过非零异常维度来表示，并在增加空间维度时正确描述向平均场行为的转变。
