BOUND-STATES NEAR A SHORT-RANGE IMPURITY IN CROSSED MAGNETIC AND ELECTRIC-FIELDS

The problem of quantum scattering of an electron by a short-range impurity in a two-dimensional electron gas in the presence of a perpendicular magnetic field and a longitudinal electric field is solved. It is shown that in addition to the bound state, which exists in the case of zero electric field, there are in an electric field N novel, nondegenerate, quasi-bound states with energies close to the Nth Landau level, irrespective of whether the impurity is attractive or repulsive.