Specific heat of a non-local attractive Hubbard model

Abstract

The specific heat of an attractive (interaction $G<0$) non-local Hubbard model is investigated. We use a two-pole approximation which leads to a set of correlation functions. In particular, the correlation function $<{\vec{S}}_i\cdot {\vec{S}}_j>$ plays an important role as a source of anomalies in the normal state of the model. Our results show that for a giving range of $G$ and $\delta$ where $\delta =1-n_T$ ($n_T=n_{\uparrow }+n_{\downarrow }$), the specific heat as a function of the temperature presents a two peak structure. Nevertehelesss, the presence of a pseudogap on the anti-nodal points $(0,\pm \pi )$ and $(\pm \pi ,0)$ eliminates the two peak structure, the low temperature peak remaining. The effects of the second nearest neighbor hopping on the specific heat are also investigated.

5 pages, 7 figures

References in corpus (3)

• Scattering and Pairing in Cuprate Superconductors
• Spectral Function of a $d-p$ Hubbard Model
• Superconductivity in an extended Hubbard model with attractive interaction