DISORDER VS INTERACTION IN THE HUBBARD-MODEL - PHASE-DIAGRAM IN INFINITE DIMENSIONS

The influence of local disorder on the thermodynamics of interacting e lectrons is studied within the infinite-dimensional disordered Hubbard model. Using a finite-temperature quantum Monte Carlo method, the ave raged local moment and staggered susceptibility are calculated and the magnetic phase diagram at half-filling is constructed. From the avera ged compressibility in the paramagnetic and antiferromagnetic phase we determine the metal-insulator transitions of the system. A rich trans ition scenario is revealed. Quite unexpectedly the disorder is found t o stabilize the magnetic order in the strong-coupling limit.