Ch. Pao et Ne. Bickers, RENORMALIZATION-GROUP ACCELERATION OF SELF-CONSISTENT-FIELD SOLUTIONS- 2-DIMENSIONAL HUBBARD-MODEL, Physical review. B, Condensed matter, 49(3), 1994, pp. 1586-1599
Momentum- and frequency-dependent self-consistent field theories provi
de a potentially powerful tool for analyzing condensed-matter models f
or interacting electrons. Such theories generally require the solution
of multidimensional integral equations. Solutions are limited by dema
nds on computational time and storage, which increase rapidly for calc
ulation of low-temperature properties. A renormalization-group techniq
ue which allows the sequential elimination of regions of high frequenc
y and momentum is presented in detail, and is then applied to the solu
tion of the fluctuation exchange approximation for the two-dimensional
Hubbard model. Effective meshes with as many as 10(4) frequencies and
512(2) k points can be analyzed on a vector supercomputer using this
approach. As a sample application, it is demonstrated that the fluctua
tion exchange approximation exhibits non-Fermi liquid behavior near ha
lf filling for sufficiently large interaction strengths.