The materials and concepts of spin electronics can bring new solutions for the realization of microwave nano-devices. The phenomenon of spin momentum transfer, playing the role of a negative resistance, allows one to induce large angle steady state magnetization oscillations, that induce a large microwave voltage signal in magneto-resistive nano-devices (<100nm).

Since 2004, our laboratory SPINTEC in collaboration with LETI, another institute of CEA Grenoble, is active in the domain, developing such spintronics oscillators. An important progress has been made, regarding the understanding of spin momentum transfer, the control of the magnetisation dynamics, the phase and amplitude noise analysis, this for different magnetic heterostructures stacks.

In order to stabilize the frequency, in this thesis new concepts for an active feedback system will be explored using specific properties of spintronics oscillators. This is the first step to realize a phase locked loop (patent LETI/SPINTEC).

The thesis is essentially experimental, but the results will be compared to existing models and to numerical simulations. The student will contribute to the development of the devices using our clean room facilities and will realize the magnetic and microwave characterisation. Then comparison between experimental results and numerical modelisation will lead the understanding of the observed phenomena.