Physical review. B, Condensed matter
Mean-field hopping solution in the Anderson-Hubbard model
R. Allub
Abstract
The tight-binding diagonally disordered Anderson model with on-site Coulomb interaction is solved in the mean-field hopping approach. Phase diagrams of the metal-insulator transition are obtained from the free energy for the half-filled band and the binary-alloy distribution. For attractive interaction (U<0), the Coulomb term gives additional localizing effect and for some values of the microscopic parameters the temperature induced two transitions (insulator to metal to insulator). For U>0 two different types of behavior are distinguished. For small disorder (W\ensuremath{\le}U/2), the metallic phase can be induced by disorder, while for large W, the disorder always destroys the phase of extended states.