Lapse of transmission phase and electron molecules in quantum dots

The puzzling behavior of the transition phase through a quantum dot can be understood in a natural way via formation of the electron molecule in the quantum dot. In this case, the resonance tunneling takes place through the quasistationary (doorway) state, which emerges when the number of electrons occupying,the dot reaches a certain "critical" value, N-cr. Our estimation of this quantity agrees with the experimental data. The dependence of N-cr on the dot's size is predicted as well.