Naslov
Third-order perturbation theory for 2-D Hubbard model. Physical Review B (2001)

Autori
Zlatić, Veljko ; Horvatić, Berislav ; Dolički, Branimir ; Grabowski, Stefan ; Entel, Peter

Izvornik
Physical review. B. (2469-9950) 63 (2001);

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
Hubbard model; spectral properties

Sažetak
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~=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.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

POVEZANOST RADA