Attractive Hubbard model and single-particle pseudogap caused by classical pairing fluctuations in two-dimensions
|Titre||Attractive Hubbard model and single-particle pseudogap caused by classical pairing fluctuations in two-dimensions|
|Type de publication||Journal Article|
|Auteurs||Vilk YM, Allen S, Touchette H, Moukouri S, Chen L, Tremblay A-MS|
|Journal||Journal of Physics and Chemistry of Solids|
It is shown that in the two-dimensional attractive Hubbard model, the mean-field phase transition is replaced by a renormalized classical regime of fluctuations where a pseudogap opens up in the single-particle spectral weight. It is argued that this pseudogap and precursors of the ordered state quasiparticles can occur only in strongly anisotropic quasi-two-dimensional materials. This precursor phenomenon differs from preformed local pairs. Further, while critical antiferromagnetic fluctuations would also lead to a pseudogap in the repulsive model, there are some important differences with thr superconducting case. (C) 1998 Elsevier Science Ltd. All rights reserved.