Fig. 2
Auto-oscillations vs. field strength: Higher-order Slonczewski modes. a–f PSD vs. applied field strength (θex = 85°), and for currents a Idc = −5 mA, b Idc = −6 mA, c Idc = −7 mA, d Idc = −8 mA, e Idc = −9 mA, and f Idc = −10 mA. The pink, red, brown, and green dashed lines represent the calculated frequencies for the SW bullet (fSWB), the FMR (fFMR), the second-order Slonczewski mode \(\left( {f_{{\mathrm{PSW}}}^{{\mathrm{2nd}}}} \right)\), and the third-order Slonczewski mode \(\left( {f_{{\mathrm{PSW}}}^{{\mathrm{3rd}}}} \right)\), respectively
