Hall effect at the magnetic-field-tuned superconductor-insulator transition

The Hall effect for disordered superconducting films in magnetic field is discussed, with special focus on the vicinity of the magnetic field-tuned superconductor-insulator transition. Evidence is presented that upon ensemble averaging this transition possesses a "hidden" particle/hole symmetry. This symmetry implies that right at the transition the Hall resistance vanishes. Relevance to recent experiments is discussed briefly. © 1991.