Quantum periodic cluster methods for strongly correlated electron systems
Abstract
Description
Quantum periodic cluster methods for strongly correlated electron systems are reformulated and developed. The reformulation and development are based on a canonical transformation which periodizes the fermions in the cluster space. The dynamical cluster approximation and the cellular dynamical mean field theory are related each other through the canonical transformation. A cluster perturbation theory with periodic boundary conditions is developed. It is found that the periodic cluster perturbation theory converges rapidly with corrections $\mathcal{O}(1/L_c^2)$, where $L_c$ is the linear size of the clusters, whereas the ordinary cluster perturbation theory converges with corrections $\mathcal{O}(1/L_c)$.
7 pages, 2 figures
7 pages, 2 figures