Interference in a quantum dot molecule embedded in a ring interferometer

Interference experiments are presented involving electronic quantum transport through an artificial quantum dot molecule in the Coulomb blockade regime embedded in a ring interferometer. Full tunability and the high stability of the structure allowed the transmission phase through this system, spin-related interference phenomena, and Fano-type interference to be studied. When a part of the interferometer is itself tuned into the Coulomb blockade regime, a phase-coherently coupled triple dot system can be investigated. The experiments demonstrate the feasibility of complex quantum circuits with a high degree of phase-coherence.