Fano resonances in electronic transport through a quantum ring with impurities

Electron transport in a two-terminal Aaronov - Bohm ring with a number of short-range scatterers on it is investigated. An analytical expression for the conductance as a function of the electron Fermi energy is obtained using the zero-range potential theory. The dependence of the conductance on magnetic flux and positions of scatterers is studied. We have found that the conductance exhibits asymmetric Fano resonances at certain energies. The dependence of Fano resonances on magnetic field and positions of impurities is investigated. It is found that collapse of the Fano resonances appears at certain conditions.