The European Physical Journal B

, Volume 67, Issue 2, pp 231–238 | Cite as

Fano effect in a double T-shaped interferometer

Mesoscopic and Nanoscale Systems

Abstract

We study the coherent transport in a one-dimensional lead with two side-coupled quantum dots using the Keldysh’s Green function formalism.The effect of the interdot Coulomb interaction is taken into account by computing the firstand second order contributions to the self-energy.We show that the Fano interference due to the resonance of one dotis strongly affected by the fixed parameters that characterize the second dot. If the second dot is tuned close to resonance an additionalpeak develops between the peak and dip of the Fano line shape of the current. In contrast, when the second dotis off-resonance and its occupation number is close to unity the interdot Coulomb interaction merely shifts the Fano line and no other maxima appear.The system we consider is more general than the single-dot interferometer studied experimentally by Kobayashi et al. [Phys. Rev. B 70, 035319 (2004)] and may be used for controlling quantum interference and studying decoherence effects in mesoscopic transport.

PACS

73.23.Hk Coulomb blockade; single-electron tunneling 85.35.Ds Quantum interference devices 85.35.Be Quantum well devices 73.21.La Quantum dots 

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Copyright information

© EDP Sciences, SIF, Springer-Verlag Berlin Heidelberg 2009

Authors and Affiliations

  1. 1.National Institute of Materials PhysicsBucharest-MagureleRomania
  2. 2.Department of PhysicsBilkent UniversityAnkaraTurkey

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