QUANTUM HALL-EFFECT IN 3-DIMENSIONAL LAYERED SYSTEMS

Using a mapping of a layered three-dimensional system with significant interlayer tunneling onto a spin Hamiltonian, the phase diagram in th e strong magnetic-field limit is obtained in the semiclassical approxi mation. This phase diagram, which exhibits a metallic phase for a fini te range of energies and magnetic fields, and the calculated associate d critical exponent v=4/3 agree excellently with existing numerical ca lculations. The implication of this work for the quantum Hall effect i n three dimensions is discussed.