Fig. 3: Nonmonotonic variation of oscillation frequency with the oscillator spacing.
From: Nonlinear dynamics of directly coupled skyrmions in ferrimagnetic spin torque nano-oscillators
a FFT spectra of rcx,1 (open symbols) and rcx,2 (solid symbols), b temporal-averaged orbit radius rc,i and c azimuthal component Fjθ,i of current-induced forces, with different oscillator spacings d12. The color bars in a represent the amplitude in Fourier transformation. The light yellow and green backgrounds indicate the synchronization and non-synchronization regions, respectively. The curves in a are the plots of Eq. (2), while the symbols in a–c represent the results of the Thiele’ s equation with the same parameters as those used in Fig. 1.
