arXiv:cond-mat/9506083 · Physical review. B, Condensed matter
Influence of next-nearest-neighbor electron hopping on the static and dynamical properties of the two-dimensional Hubbard model
Daniel Duffy, Adriana Moreo
Abstract
Comparing experimental data for high-${\mathit{T}}_{\mathit{c}}$ cuprate superconductors with numerical results for electronic models, it is becoming apparent that a hopping along the plaquette diagonals has to be included to obtain quantitative agreement. However, the values for ${\mathit{t}}^{\ensuremath{'}}$ discussed in the literature were obtained comparing theoretical results in the weak-coupling limit with photoemission data and band-structure calculations. The goal of this paper is to study how ${\mathit{t}}^{\ensuremath{'}}$ gets renormalized as the interaction between electrons, U, increases. For this purpose, the effect of adding a bare diagonal hopping ${\mathit{t}}^{\ensuremath{'}}$ to the two-dimensional Hubbard model Hamiltonian is investigated using numerical techniques. Spin-spin correlations, n(k), 〈n〉 vs \ensuremath{\mu}, and local magnetic moments are studied for several values of U/t and the electronic density. The spectral function A(k,\ensuremath{\omega}) is also discussed. We introduce a criterion to determine probable locations of Fermi surfaces at zero temperature. In general, we conclude that it is very dangerous to extract a bare parameter of the Hamiltonian (${\mathit{t}}^{\ensuremath{'}}$) from photoemission spectroscopy data where renormalized parameters play the important role.