One-dimensional large-U Hubbard model in strong coupling

A.G Izergin, A.G Pronko, N.I Abarenkova

Zheng-Yu Weng, D. N. Sheng, C. S. Ting

A path-integral formalism of the Hubbard model is used to study the one-dimensional large-U case. It is shown that the bare electron (hole) becomes a composite particle of two decoupled excitations, holon and spinon, together with the non-local string fields. Various correlation functions are analytically derived. The results strongly suggest a U*=∞ fixed point of Hubbard model which is distinct from the weak coupling case.

Ian P. McCulloch, M. Gulácsi

Alberto Parola, Sandro Sorella

The large-distance behavior of the spin-spin correlation function of the one-dimensional repulsive Hubbard model is evaluated analytically in the strong-coupling regime at quarter filling. In this case, its power-law decay is characterized by an exponent \ensuremath{\gamma}=3/2. We have found that this behavior is generally valid at any nonzero doping, although our argument is not mathematically rigorous away from quarter filling. These results strongly suggest that the renormalization-group scaling to the Tomonaga-Luttinger model is exact in the U\ensuremath{\rightarrow}\ensuremath{\infty} Hubbard model.

Alain Messager, Сергей Анатольевич Пирогов, Yuri Suhov

G. Uimin, С. В. Фомичев