A NEW UNIVERSALITY CLASS FOR THE METAL-INSULATOR-TRANSITION PROBLEM

A new scenario is proposed for a class of disordered interacting electronic systems undergoing a metal-insulator transition. The scenario applies in the absence of spin-flip mechanisms to systems that are not nearly ferromagnetic. At the phase transition both the spin susceptibility and the coefficient of the linear tem in the specific heat diverge with identical exponents, and the electrical conductivity vanishes continuously with a different exponent. Approximate values am given for the critical exponents of transport and thermodynamic properties in three-dimensional systems.