Variational cluster approach to correlated electron systems in low dimensions.
A self-energy-functional approach is applied to construct cluster approximations for correlated lattice models. It turns out that the cluster-perturbation theory [Phys. Rev. Lett. 84, 522 (2000)]] and the cellular dynamical mean-field theory [Phys. Rev. Lett. 87, 186401 (2001)]] are limiting cases of a more general cluster method. The results for the one-dimensional Hubbard model are discussed with regard to boundary conditions, bath degrees of freedom, and cluster size.
Potthoff
M
M
Institut für Theoretische Physik, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.
Aichhorn
M
M
Dahnken
C
C