Two-dimensional electrons in modulated magnetic fields

Abstract

New systems are proposed in which the electron motion in a two-dimensional electron gas (2DEG) is altered by the presence of a non-homogeneous magnetic field. We show that an array of ferromagnetic strips leads to magnetic minibands in the 2D electron spectrum. A random array of ferromagnetic disks results into a Hall resistance which is not determined by the average magnetic field. The third system we studied consists of a superconducting disk on top of the 2DEG which leads to magnetic confinement for the electrons and discrete filling of the magnetic dot.