Phase rigidity and avoided level crossings in the complex energy plane

E. N. Bulgakov, I. Rotter, A. F. Sadreev

We consider the effective Hamiltonian of an open quantum system, its biorthogonal eigenfunctions ${\varphi }_{\lambda }$ and define the value $r_{\lambda }=({\varphi }_{\lambda }|{\varphi }_{\lambda })/<{\varphi }_{\lambda }|{\varphi }_{\lambda }>$ that characterizes the phase…