Spin-dependent resonant tunneling was investigated in fully epitaxial Cr(001)/ultrathin Fe(001)/MgO(001)/Fe(001) pseudo double-barrier magnetic tunnel junctions (MTJs) by varying structural coherence of the MgO barrier through postdeposition annealing and Mg layer insertion. It was clearly demonstrated that not only the flatness of the Fe quantum-well layer, but also the structural coherence of the MgO barrier caused the appearance of sharp resonant conductance peaks which were not obtained for spin-dependent resonant tunneling in amorphous AlO-barrier MTJs. The symmetry-selective transport via MgO barrier plays a crucial role for the resonant tunneling as well as large tunneling magnetoresistance.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)