Premium
Role of inter‐dot Coulomb repulsion and exchange interactions on transport in double quantum dot
Author(s) -
Michałek Grzegorz,
Bułka Bogdan R.
Publication year - 2006
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.200562424
Subject(s) - quantum dot , quantum tunnelling , condensed matter physics , kondo effect , coupling (piping) , physics , slave boson , coulomb , electron , conductance , resonance (particle physics) , coulomb blockade , quantum mechanics , voltage , materials science , superconductivity , transistor , metallurgy , hubbard model
Effects of inter‐dot many‐body electronic correlations on the coherent transport through double quantum dots (DQD) connected in series are studied. Conductance as well as another physical quantities are calculated by means of Green's functions. The many‐body electronic correlations are treated in the slave‐boson (SB) mean‐field approach, developed by Kotliar and Ruckenstein. The conductance in the model is characterized by competition between the dot–dot tunnelling coupling and the level broadening (dot–lead coupling). In the case, when the inter‐dot coupling is weaker than the dot–lead coupling each dot accommodates one electron and forms the Kondo resonant state with conducting electrons in a lead. In the opposite limits, when the inter‐dot coupling exceeds level broadening, the conductance vanishes for sufficiently low gate voltages, which means the Kondo effect disappeared. The resonance region is broadened with increasing inter‐dot Coulomb repulsion as well as with decreasing exchange interactions. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)