Photon-assisted electron transport through a three-terminal quantum dot system with nonresonant tunneling channels

We have studied the electron transport through a quantum dot coupled to three leads in the presence of external microwave fields supplied to different parts of the considered mesoscopic system. Additionally, we introduced a possible nonresonant tunneling channels between leads. The quantum dot charge and currents were determined in terms of the appropriate evolution operator matrix elements and under the wide band limit the analytical formulas for time-averaged currents and differential conductance were obtained. We have also examined the response of the considered system on the rectangular-pulse modulation imposed on different quantum dot-leads barriers as well as the time-dependence of currents flowing in response to suddenly removed (or included) connection of a quantum dot with one of the leads.Comment: 34 pages, 12 figure

Influence of microwave fields on the electron transport through a quantum dot in the presence of a direct tunneling between leads

We consider the time-dependent electron transport through a quantum dot coupled to two leads in the presence of the additional over-dot (bridge) tunneling channel. By using the evolution operator method together with the wide-band limit approximation we derived the analytical formulaes for the quantum dot charge and current flowing in the system. The influence of the external microwave field on the time-average quantum dot charge, the current and the derivatives of the average current with respect to the gate and source-drain voltages has been investigated for a wide range of parameters.Comment: 28 Pages, 11 Postscript figure