https://doi.org/10.1007/s100510050279
Dynamical spin and charge response functions in the doped two-dimensional Hubbard model
Centro Internacional de Física da Matéria Condensada - ICCMP,
Universidade de Brasília,
CEP 70919-970 Brasília-DF, Brazil
Corresponding author: a saikawa@iccmp.br
Received:
25
September
1997
Revised:
19
December
1997
Accepted:
9
January
1998
Published online: 15 May 1998
Dynamical properties of the spin and charge response functions in the doped two-dimensional Hubbard model are calculated by taking into account the drastic separation of the single-particle spectral function into the low-energy coherent and high-energy incoherent parts due to the strong Coulomb interaction. We show that this evolution of the electronic states is the origin of the broad and structureless feature in the charge response function. In the weak coupling regime the low-energy enhancement of the spin excitation is produced which can be explained within the random phase approximation. However, for the larger interaction close to the antiferromagnetic Stoner condition, the low-energy intensity of the spin excitation is suppressed.
PACS: 71.27.+a – Strongly correlated electron systems; heavy fermions / 75.40.Gb – Dynamic properties (dynamic susceptibility, spin waves, spin diffusion, dynamic scaling, etc.) / 71.10.Fd – Lattice fermion models (Hubbard model, etc.)
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 1998
