Magnetic-field-driven metal-insulator transition in Kondo insulators

We present a scaling theory to describe the magnetic-field-driven metal-ins ulator (MI) transition in Kondo insulators, in the case where both the insu lating and metallic phases are nonmagnetic. Starting from the insulator the uniform magnetic field may drive the system continuously to a metallic sta te. The universality class of this MI transition is identified as that of d ensity-driven transitions for which all critical exponents are known. At th e critical field, where the metal-insulator transition occurs, the system p resents non-Fermi liquid behavior and we determine its thermodynamic proper ties. In two dimensions there is a universal conductivity at the MI transit ion whose value is given. A functional integral approach is used to obtain results in 3d systems. [S0163-1829(99)01027-9].