Current-driven excitations in symmetric magnetic nanopillars

A detail measurement of the current-induced excitations in symmetric multilayer nanopillars was presented. The features of symmetric pillars was to test various models of current-induced excitations. It was observed that only one layer was excited in multilayer but currents of opposite polarities excite different layers. The study suggests an energy threshold for the excitation that could be qulaitatively explained on the basis of spin accumulation in symmetric trilayer structures, where currents of different polarities excite different magnetic layers.