Antisymmetric magnetoresistance of the SrTiO3/LaAlO3 interface

The longitudinal resistance R-xx of the SrTiO3/LaAlO3 interface with magnetic fields applied perpendicular to the interface has an antisymmetric term [namely, R-xx(H)not equal R-xx(-H)] which increases with decreasing temperature and increasing field. We argue that the origin of this phenomenon is a nonhomogeneous Hall effect with clear contribution of an extraordinary Hall effect, suggesting the presence of nonuniform field-induced magnetization.