Mode entanglement of an electron in one-dimensional determined and random potentials

By using the measure of concurrence, mode entanglement of an electron moving in four kinds of one-dimensional determined and random potentials is studied numerically. The extended and local- ized states can be distinguished by mode entanglement. There are sharp transitions in concurrence at mobility edges. It provides that the mode entanglement may be a new index for a metal-insulator transition.