Control of bond formation, electron transport, and interference in a biased asymmetric parallel double-dot system

Abstract

We analyze electron transport through a biased asymmetric double-dot system in a parallel arrangement between leads. We show that the imposition of a dot-to-dot bias induces changes in the symmetry of the wave functions associated with the double-dot energy levels, resulting in a dip in the dependence of the lead-to-lead current on dot-to-dot bias. We also demonstrate that when the dot-to-dot bias compensates (energetically) the structure asymmetry, the lead-to-lead current will be an oscillating function of an applied magnetic field in the case in which only one of the double-dot levels is conductive. However, destructive interference between different parts of the same dot gives rise to suppression of current at high magnetic fields.