High Amplitude Microwave Generation Using Domain Wall Motion in a Nanowire

Microwave generation has been extensively investigated due to their application in telecommunication and promising use in emerging technologies like internet-of-things (IoT) devices. The current approaches to generate microwave using voltage-controlled oscillators have the problem of high power consumption. Spin torque oscillators have been investigated as an alternative, but they suffer from a weak output signal. Hence, there is a need for an alternative approach which overcomes these issues. Here a new approach is reported, which relies on the motion of domain walls to generate microwave with strong signal and lower power consumption. In this study, a magnetic nanowire with a sequence of oppositely magnetized domains in one half of the nanowire is simulated. The domain walls are moved by applying spin-orbit torque to the nanowire. It is proposed to generate microwave by detecting the changes in magnetization value using a magnetic tunnel junction in real application. The oscillating frequency of magnetization is found to be in GHz. It is demonstrated that the frequency can be tuned by varying the applied current density. The outcome of this work promises the application of the reported method to generate microwave in nanoscale devices of the future.