Resonant and coherent transport through Aharonov-Bohm interferometers with coupled quantum dots

Research paper by V. Moldoveanu, M. Ţolea, A. Aldea, B. Tanatar

Indexed on: 13 Oct '04Published on: 13 Oct '04Published in: Physics - Mesoscopic Systems and Quantum Hall Effect


A detailed description of the tunneling processes within Aharonov-Bohm (AB) rings containing two-dimensional quantum dots is presented. We show that the electronic propagation through the interferometer is controlled by the spectral properties of the embedded dots and by their coupling with the ring. The transmittance of the interferometer is computed by the Landauer-B\"uttiker formula. Numerical results are presented for an AB interferometer containing two coupled dots. The charging diagrams for a double-dot interferometer and the Aharonov Bohm oscillations are obtained, in agreement with the recent experimental results of Holleitner {\it et al}. [Phys. Rev. Lett. {\bf 87}, 256802 (2001)] We identify conditions in which the system shows Fano line shapes. The direction of the asymetric tail depends on the capacitive coupling and on the magnetic field. We discuss our results in connection with the experiments of Kobayashi {\it et al} [Phys. Rev. Lett. {\bf 88}, 256806 (2002)] in the case of a single dot.