The research goal of this award is the parallel development of theoretical and computational methods for modeling and analyzing the collective behavior of arrays of Spin Torque Nano-Oscillators (STNOs). These types of nano-oscillators consist of at least two layers of ferromagnetic materials separated by a nonmagnetic metal layer. A spin-polarized current applied through the layers can facilitate a local torque, thus exciting steady oscillations and small microwave voltage signals. The research will result in general methods to study complex systems in science and engineering, and, in particular, to model, design and fabricate arrays of STNOs with larger microwave power output. The research approach progresses from the analysis of the underlying bifurcations that lead to synchronized oscillations to the design and fabrication of a nano-scale microwave signal generator. Deliverables include modeling and bifurcation analysis tools, hardware prototype, research reports, math and engineering research experience and education for students.
The results of this project have the potential to lead to the fabrication of a nano-scale microwave signal generator that should be tuneable over a broad frequency band, about 40 GHz. Such frequency range will render the microwave device ideal for many applications, including telecommunications ( e.g., wireless systems), radar( e.g. air traffic control, weather forecasting), antennas and navigation systems. The theoretical foundation for fabricating such device lies on the conjecture by various research groups that a possible solution to increase microwave power output is to synchronize several STNOs so that a coherent signal with a common frequency and phase can be extracted from the ensemble. Graduate and undergraduate engineering, math, and physics students, will be recruited for classroom instruction and to participate in research activities. Dissemination and outreach activities at various venues will be conducted.
