Control of spin-wave emission from spin-torque nano-oscillators by microwave pumping

We demonstrate that microwave pumping of a spin-torque nano-oscillator can lead to transfer of the spin-wave energy generated by the oscillator into a mode with frequency given by the difference between the pumping frequency and that of the auto-oscillation. The decay length of spin waves at the combination frequency is significantly increased, while the directionality of emission is preserved. The observed phenomenon provides a route for the implementation of nanosized spin-wave emitters with controllable emission characteristics for applications in next-generation microwave electronic devices.