vector ${\bf
  m}$ in the direction of the switching magnet moment. The LLG equation takes the usual form $$\label{llg}
\frac{{\rm d}{\bf m}}{{\rm d}t}+\gamma{\bf m}\times\frac{{\rm d}{\bf m}}{{\rm d}t}={\bm\Gamma}$$ where the reduced total torque ${\bm\Gamma}$ acting on the switching magnet is given by $$\label{Gamma}
{\bm\Gamma}=\left[-\left({\bf H}_{\rm A}+{\bf H}_{\rm
    ext}\right)\times\langle{\bf S}_{\rm tot}\rangle+{\bf
    T}_{\perp}+{\bf T}_{\parallel}\right]/
\left|\langle {\bf S}_{\rm tot}\rangle\right|.$$ Here ${\bf H}_{\rm ext}$ is an external field, in the same frequency units as ${\bf H}_{\rm A}$, and $\gamma$ is the Gilbert damping parameter. Following Sun [@sun], Eq. (\[llg\]) may be written more conveniently as $$\label{Gamma2}
\left(1+\gamma^2\right)\frac{{\rm d}{\bf m}}{{\rm
    d}t}={\bm\Gamma}-\gamma{\bf m}\times{\bm\Gamma}.$$ It is also useful to measure the strengths of all the torques in units of the strength of the uniaxial anisotropy [@sun]. We shall, therefore, write the total reduced torque ${\bm\Gamma}$ in the form $$\label{Gamma3}
{\bm\Gamma}=H_{uo}\left\{({\bf m}\cdot{\bf e}_{z}){\bf m}\times{\bf e}_z-
h_{\rm p}({\bf m}\cdot{\bf e}_{y}){\bf m}\times
{\bf  e}_y+v_{\parallel}(\psi)
{\bf m}\times({\bf p}\times{\bf m})+\left[v_{\perp}(\psi)+h_{\rm ext}\right]
{\bf m}\times{\bf p}\right\}$$ where the relative strength of the easy plane anisotropy $h_{\rm
  p}=H_{\rm p0}/H_{\rm u0}$ and $v_{\parallel}(\psi)=vg_{\parallel}(\psi)$, $v_{\perp}(\psi)=vg_{\perp}(\psi)$ measure the strengths of the torques ${\bf T}_{\parallel}$ and ${\bf T}_{\perp}$. The reduced bias is defined by $v=eV_{\rm b}/(|\langle {\bf S}_{\rm
  tot}\rangle|H_{\rm u0})$ and has the opposite sign from the bias voltage since 