Figure 4
From: Injection locking of multiple auto-oscillation modes in a tapered nanowire spin Hall oscillator
Injection locking of the SHO. Microwave frequencies are applied in the range between 4.5 and 6.2 GHz at a nominal ac output power of 0.06 mW and a driving current of Idc = 2.5 mA. Measurement position on bullet A at x = 500 nm. The frequencies (a,b), amplitudes (c) and FWHM (d) are shown for bullet A (blue hollow squares) and the SSW mode (black dots). The black and blue solid lines serve as a guide to the eye. The estimated locking intervals of about 100 MHz width centered around the auto-oscillation frequencies of 5.2 and 5.57 GHz are marked by light-blue and grey boxes, respectively. Within these windows, frequency locking, amplitude enhancement/suppression, and linewidth reduction (detection limit marked by a red line in c) are observed.
