Dynamical vertex approximation in its parquet implementation: Application to Hubbard nanorings

作者:Valli A*; Schaefer T; Thunstroem P; Rohringer G; Andergassen S; Sangiovanni G; Held K; Toschi A
来源:Physical Review B, 2015, 91(11): 115115.
DOI:10.1103/PhysRevB.91.115115

摘要

We have implemented the dynamical vertex approximation (D Gamma A) in its full parquet-based version to include spatial correlations on all length scales and in all scattering channels. The algorithm is applied to study the electronic self-energies and the spectral properties of finite-size one-dimensional Hubbard models with periodic boundary conditions (nanoscopic Hubbard rings). From a methodological point of view, our calculations and their comparison to the results obtained within dynamical mean-field theory, plain parquet approximation, and the exact numerical solution allow us to evaluate the performance of the D Gamma A algorithm in the most challenging situation of low dimensions. From a physical perspective, our results unveil how nonlocal correlations affect the spectral properties of nanoscopic systems of various sizes in different regimes of interaction strength.

  • 出版日期2015-3-6