Tunneling magnetoresistance oscillations due to charging effects in MgO double barrier magnetic tunnel junctions

We observe single-electron tunneling effect and tunneling magnetoresistance (TMR) oscillations in MgO double barrier magnetic tunnel junctions patterned with electron beam lithography and argon ion milling. The TMR oscillations are induced by the interplay of single charge effect and spin-dependent tunneling. The oscillations and its period can be well-controlled by properly engineering the thickness of MgO tunnel barriers and the size of the tunnel junctions. © 2012 American Institute of Physics.