Coherent transport through T-shaped electrostatically coupled quantum dots

• Published in: Journal of magnetism and magnetic materials Vol. 310; no. 2; pp. 2423 - 2424
• Main Authors: Lipinski, S., Krychowski, D.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 01.03.2007; Elsevier Science
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Cross-disciplinary physics: materials science; rheology; Electronic transport in condensed matter; Exact sciences and technology; Kondo effect; Magnetic properties and materials; Materials science; Nanoscale materials and structures: fabrication and characterization; Physics; Quantum dot; Quantum dots; Spin polarized transport; 72.15.Qm; Spin polarized transport; Quantum dot; Kondo effect; 73.63.Kv; 72.25.Dc; 75.20.Hr; Fano effect; Voltage dependence; Quantum dots; Open systems; Magnetic field effects; 72.15.Qm; 72.25.Dc; 73.63.Kv; 75.20.Hr; Boson field; Spin polarized transport; Quantum dot; Kondo effect; Equations of motion; Spin filter
• ISSN: 0304-8853
• DOI: 10.1016/j.jmmm.2006.10.811

The Fano–Kondo resonance is studied in a system consisting of a pair of side-coupled double quantum dots attached to quantum wires. The double dots are capacitively coupled. The mean field slave boson approach and the equation of motion method are used. For symmetric dots Kondo effect has two possible sources: spin and charge degeneracies. The conductance as a function of gate voltage is characterized by a Fano asymmetric parameter q. For q=0 a half-reflection is observed. The same value of transmission is expected in the limit q→∞. For intermediate cases transmission line has a general asymmetric Fano-type shape. We show that by tuning the gate voltage or changing magnetic field, the single spin-orbital Kondo channel opens and the system can operate as a spin filter.