Renormalization Group Approach to Self-Consistent-Field Approximation for the Interacting Electrons

C.-H. Pao

Chinese Journal of Physics

38卷2S期（2000 / 04 / 01）

375 - 379

英文

Due to the retarded nature of the phonon-mediated electron-electron interaction, neither fast Fourier transform (FFT) nor previously developed NRG methods for Hubbard-type purely electronic models are applicable, while brute-force solutions are limited by the demands on computational time and storage which increase rapidly at low temperature T. A new numerical renormalization group (NRG) approach to the solution of self-consistent-field equations for correlated lattice electrons is illustrated for the two-dimensional Hubbard-type model. This approach allows us to handle the fermion frequency matrix inversions in the FLEX equations efficiently. Several orders of magnitude of CPU time and storage can be saved at the temperature scales relevant to electronic phase transitions.