Perturbation expansion for 2-D Hubbard model

Abstract

We develop an efficient method to calculate the third-order corrections to the self-energy of the hole-doped two-dimensional Hubbard model in space-time representation. Using the Dyson equation we evaluate the renormalized spectral function in various parts of the Brillouin zone and find significant modifications with respect to the second-order theory even for rather small values of the coupling constant U. The spectral function becomes unphysical for $U\simeq W$, where W is the half-width of the conduction band. Close to the Fermi surface and for U<W, the single-particle spectral weight is reduced in a finite energy interval around the Fermi energy. The increase of U opens a gap between the occupied and unoccupied parts of the spectral function.

17 pages, 11 Postscript figures, Phys. Rev. B, accepted

Cited by in corpus (10)

• ARPES Spectra of the Hubbard model
• Nonequilibrium magnetotransport through a quantum dot: An interpolative perturbative approach
• Optimal grouping of arbitrary diagrammatic expansions via analytic pole structure
• Algorithmic approach to diagrammatic expansions for real-frequency evaluation of susceptibility functions
• Kohn-Luttinger instability of the t-t' Hubbard model in two dimensions: variational approach
• Pairing Fluctuations in The Attractive Hubbard Model in the Atomic Limit
• Fourth-Order Perturbation Expansion for Hubbard Model on a Two-Dimensional Square Lattice
• Nonlocal Excitation Spectra in 2D Doped Hubbard Model
• Analyzing the success of T-matrix diagrammatic theories in representing a modified Hubbard model
• Phase diagrams of correlated electrons: systematic corrections to the mean field theory