Selective control of vortex polarities by microwave field in two robustly synchronized spin-torque nano-oscillators

摘要

Manipulating operation states of coupled spin-torque nano-oscillators(STNOs), including their synchronization, is essential for applications such ascomplex oscillator networks. In this work we experimentally demonstrateselective control of two coupled vortex STNOs through microwave-assistedswitching of their vortex core polarities. First, the two oscillators are shownto synchronize due to dipolar interaction in a broad frequency range tuned byexternal biasing field. Coherent output is demonstrated along with stronglinewidth reduction. Then, we show individual vortex polarity control of eachoscillator, which leads to synchronization/desynchronization due to accompaniedfrequency shift. Our methods can be easily extended to multiple-element coupledoscillator networks.