Interference Effect in Multilevel Transport through a Quantum Dot
Journal of the Physical Society of Japan
We present experimental results and a model to solve the problem of "in-phase Coulomb peaks" observed in transport through a quantum dot. In a marginal region between Coulomb-blockade and open-dot, we have observed Fano-type interference through two energy levels inside the dot, which manifest themselves in two overlapped Coulomb-diamond-like structures in the excitation spectrum. One of the two levels is strongly coupled to the leads and the phase of traversing electrons is locked to it. We
... e detected the phase change at the vertices and the centers of the larger diamonds through the sign of the Fano's asymmetric parameters supporting the above deduction.