Physical review. B, Condensed matter
Localization in the three-dimensional Hubbard model at finite temperature
Fa-jian Shi, Tsung-han Lin
Abstract
With the aid of functional-integral technique, we show that the strongly correlated electron system described by the Hubbard model at finite temperature is approximately equivalent to the dynamically disordered electron system. For larger Coulomb interaction U, we show that it has localized states in the middle region of the band. Thus, the system exhibits a continuous metal-insulator transition, in which the activation energy for conduction is continuous, caused purely by the electron-electron interaction near half filling.