Fano resonances in electronic transport through a single-electron transistor

We have observed asymmetric Fano resonances in the conductance of a single-electron transistor resulting from interference between a resonant and a nonresonant path through the system. The resonant component shows all the features typical of single-electron addition to the confined droplet within the transistor, but the origin of the nonresonant path is unclear. A feature of this experimental system, compared to others that show Fano line shapes, is that changing the voltages on various gates allows one to alter the interference between the two paths.