Quantum transport through a quantum well in the presence of a finite-rangetime-modulated potential

We have studied the transport of electrons through a quantum well within wh ich a time-modulated potential of amplitude V-2, range a, and frequency w i s applied. Our results show that, as the chemical potential mu increases, t he de conductance G exhibits Fano-structures when mu is at m (h) over bar w above the bound state energy in the well. As V-2 increases, the Fano-struc tures are broadened, and higher m (h) over bar w processes emerge. These fe atures are identified as the formation of quasi-bound states. For a fixed b ut large potential strength V-1 = aV(2), the Fano-structures are broadened and are shifted toward lower electron energies, as a decreases. The depende nce of the Fano-structure to the location of the time-modulated potential i s also studied.