Wave-vector filtering and spin filtering in a magnetic double-barrier and double-well structure

Abstract

We investigate wave-vector filtering and spin filtering for electrons tunneling through a magnetic double-barrier and double-well quantum structure in the presence of an external electric field, where the double magnetic wells are within or outside the double magnetic barriers. It is shown that electronic resonant tunneling shows strong wave-vector-dependent enhancement and suppression as the applied bias increases. It is also shown that although the current density decreases with the strength of the inhomogeneous magnetic field increasing, the degree of spin polarization is generally enhanced and shows a more wider and nearly 100% spin polarization plateau in small external bias range. The general rules for relations between wave-vector filtering and the magnetic configuration as well as between spin filtering and the magnetic configuration are summarized and explained.