Spin transfer nano-oscillators

Spin transfer nano-oscillator (STO), a new class of nano-sized microwave device based on giant magnetoresistance and spin transfer torque effect, has aroused tremendous and continuous research interest due to its potential applications in wireless communications system as either microwave source or detectors. The key features of STOs are simple structure, nanoscale size, frequency tunability, broad working temperature, low operating voltage and easy integration with standard silicon technology. In this review paper, we give an overview of the working principle of STOs, recent developments and breakthroughs. Challenges and perspectives of the STOs that might be productive topics for future research are also briefly discussed.