Tunneling processes in asymmetric double barrier magnetic tunnel junctions with a thin top MgO layer

Abstract

Dynamic conductance dI/dV and inelastic electron tunneling spectroscopy (IETS) d 2 I/dV 2 have been measured at different temperatures for double barrier magnetic tunnel junctions with a thin top MgO layer. The resistance in the antiparallel state exhibits a normal tunnel-like behavior, while the resistance in the parallel state shows metallic-like transport, indicating the presence of pinholes in the thin top MgO layer. Three IETS peaks are the zero-bias anomaly, interface magnons, and barrier phonons in both the parallel and antiparallel states. The zero-bias anomaly is the strongest peak in the parallel state and its intensity decreases with temperature. The magnon has the largest intensity in the antiparallel state and its intensity also decreases with temperature. The origins of the dips and peaks in the dI/dV-V curve are also discussed. V C 2013 AIP Publishing LLC.

Temperature dependence of shot noise in double barrier magnetic tunnel junctions

“…MTJs based on symmetrypreserved tunneling have been used for read heads of hard disk drives and data storage such as STT-MRAM 10 . Double barrier magnetic tunnel junctions(DBMTJs) have potential advantages over single barrier magnetic tunnel junctions(SBMTJs) due to their better signal to noise ratio [11][12][13][14][15] . DBMTJ can generate a larger output voltage at the relevant operating voltage, which can improve the signal to noise ratio 16,17 .…”

Low frequency noise in asymmetric double barrier magnetic tunnel junctions with a top thin MgO layer

“…[2,3] Recently double barrier magnetic tunnel junctions (DBMTJs) have also drawn attention for possible advantages over SBMTJs. [4][5][6][7][8][9] In the simplest case, they can be regarded as two SBMTJs in series, [10,11] so larger output voltage can be generated, which improves signal noise ratio.…”