Parametric Resonance of Magnetization Excited by Electric Field

This thesis describes the experiments that demonstrate the ability to efficiently excite magnetization parametrically by electric field. The experiments are done with nanoscale magnetic tunnel junctions, which are multilayer thin film devices patterned into nanopillar shape. One of the layers possesses strong perpendicular magnetic anisotropy and exhibits strong voltage-controlled magnetic anisotropy. This magneto-electric effect allows one to modulate the perpendicular magnetic anisotropy of the layer and parametrically excite large-amplitude oscillations of the magnetization. The results of this experiment show that it is possible to parametrically excite resonance in a magnetic nanostructure using electric field and that the threshold voltage for this process is low: it is found to be well below 1Volt. This paves the way towards developing energy-efficient spintronic devices based on parametric excitation of magnetization by electric field