Quenching of Magnetoresistance by Hot Electrons in Magnetic Tunnel Junctions

Abstract

A zero bias anomaly is observed at low temperatures in the current-voltage characteristics of ferromagnetic tunnel junctions; the drop in the junction resistance with increasing bias voltage is greater for antiparallel alignment of the magnetic moments of the magnetic electrodes than for parallel alignment. The resulting decrease in the magnetoresistance of the junction is accounted for by spin excitations localized at the interfaces between the magnetic electrodes and the tunnel barrier.