Transport in Two-Dimensional Electron Gas with Isolated Magnetic Barriers

Abstract

We have studied the transport in two-dimensional electron gas (2DEG) subjected to two different types of magnetic barriers-dipolar and monopolar barriers-using fringing magnetic field from ferromagnetic film on the surface of GaAs/AlGaAs heterostructures. Resistivity of 2DEG increases as the magnetic barriers are turned on. We measured amplitude dependence and temperature dependence of the excess resistivities due to those magnetic barriers. The resistance as a function of the uniform component of the magnetic field exhibits a positive magnetoresistance and a beating pattern of the Shubnikov-de Haas oscillations. They are qualitatively explained by considering the various cyclotron trajectories in the region of the magnetic barriers.