 $$\begin{aligned} \left(\begin{array}{c}\phi_{0}\\\phi_{0} \end{array}\right)_x&=& U\left(\begin{array}{c} \phi_{0}\\\phi_{0} \end{array}\right),\quad U=\frac{0}{0}\left( \begin{array}{cc} -\alpha & \lambda m\\  -\lambda  