Figure 1

(Color online) (a) Inset: representative power spectral density normalized by $I_{dc}^2$, obtained for $I_{dc}=1\text{mA}$ and $H=110\text{Oe}$ at $T=300\text{K}$. Two large peaks are observed labeled low frequency (LF) and high frequency (HF) modes. Main panel: variation of the frequency of the LF mode (black squares) with $I_{dc}$ for $H=110\text{Oe}$ at $T=300\text{K}$. The lines are linear fits corresponding to the two regimes discussed in the text. (b) Left axis: black squares represent the linewidth of the LF mode as a function of $I_{dc}$ for $H=110\text{Oe}$ and $T=300\text{K}$. Right axis: evolution of the calculated nonlinear amplification factor $A_{NL}$ (red triangles) with. $I_{dc}$ (c) Left axis: dependence of the calculated $p_n=\Delta f{p}_0/A_{NL}{\Gamma }_g$ (black squares) on $I_{dc}$. Right axis: relative variation with $I_{dc}$ of the normalized background noise level (red triangles).Reuse & Permissions

Figure 2

(Color online) Variation of the linewidth with $I_{dc}$ for $T=20$, 180 and 300 K and $H=205\text{Oe}$. Inset: variation of the frequency with $I_{dc}$ for $H=205\text{Oe}$ and $T=20\text{K}$.Reuse & Permissions

Figure 3

(Color online) (a) Temperature dependence of the calculated noise level $p_n$ for $I_{dc}=1$, 1.4, and 1.7 mA for $H=205\text{Oe}$. (b) Left axis: temperature variation of linewidth for $I_{dc}=0.5\text{mA}$. Right axis: temperature variation of the nonlinear amplification parameter $A_{NL}$ calculated for $I_{dc}=0.5\text{mA}$ and $H=205\text{Oe}$.Reuse & Permissions