Shot noise in strongly correlated double quantum dots

Article Article scientifique Article Shot noise in strongly correlated double quantum dots eng 2004 author Lopez Pedrosa Rosa Carmen 80911 author Aguado Ramón author Platero Gloria 10.1103/PhysRevB.69.235305 1098-0121 We have investigated theoretically the shot noise of strongly correlated double quantum dot systems in the regime where the Kondo effect and the interdot antiferromagnetic exchange do compete. Our calculations are based on a generalization to nonequilibrium transport of the two-impurity Anderson Hamiltonian which is solved by the slave-boson mean-field theory. This mean-field approach together with nonequilibrium Green's-function techniques allow us to obtain closed formulas for the shot noise in the strong-coupling regime. Two configurations are considered: series and parallel. When the two quantum dots are in series, we obtain at low voltages, a nonmonotonic behavior of the Fano factor, as a function of the interdot tunneling coupling. When the competition between the Kondo effect and the interdot antiferromagnetic exchange starts to play a role this picture is strongly modified. In a parallel configuration, the functional form of the Fano factor as a function of the applied voltage V dc changes abruptly, depending on whether the ratio between the antiferromagnetic exchange constant J and the Kondo temperature T K is below or above (J∕T K )c ≃2.5 . Below (J∕T K ) c , the Fano factor behaves as in the single quantum dot case (monotonic dependence which saturates at large voltages). Above (J∕T K ) c , the Fano factor exhibits a nonmonotonic dependence on voltage, with a kink at eV dc =J . Dewey 500.2 37 Département de physique théorique 133 false Physical review. B, Condensed matter and materials physics 69 23 6b94faed-c30c-42b4-a532-cf386310f2b8 Article (Published version) Restricted Ramón Aguado.pdf 488861 application/pdf restrictedAccess Faculté des sciences / Section de physique / Département de physique théorique

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Shot noise in strongly correlated double quantum dots	Physical review. B, Condensed matter and materials physics			2004	499	0

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Lopez Pedrosa, Rosa Carmen