Fano resonance in a quantum wire with a side-coupled quantum dot

Abstract

We report a transport experiment on the Fano effect in a quantum connecting wire with a side-coupled quantum dot (QD). The Fano resonance occurs between the QD and the “T-shaped” junction in the wire, and the transport detects antiresonance or a forward-scattered part of the wave function. While it is more difficult to tune the shape of the resonance in this geometry than in the previously reported Aharonov-Bohm-ring-type interferometer, the resonance purely consists of the coherent part of transport. Utilizing this advantage, we have quantitatively analyzed the temperature dependence of the Fano effect by including the thermal broadening and the decoherence. We have also proven that this geometry can be a useful interferometer for measuring the phase evolution of electrons at a QD.