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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Spin-polarized conductance in double quantum dots: Interplay of Kondo, Zeeman, and interference effects

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Author(s):
Dias da Silva, Luis G. G. V. [1] ; Vernek, E. [2] ; Ingersent, K. [3] ; Sandler, N. [4, 5, 6, 7] ; Ulloa, S. E. [4, 5, 6, 7]
Total Authors: 5
Affiliation:
[1] Univ Sao Paulo, Inst Fis, BR-05315970 Sao Paulo - Brazil
[2] Univ Fed Uberlandia, Inst Fis, BR-38400902 Uberlandia, MG - Brazil
[3] Univ Florida, Dept Phys, Gainesville, FL 32611 - USA
[4] Ohio Univ, Dept Phys & Astron, Athens, OH 45701 - USA
[5] Ohio Univ, Nanoscale & Quantum Phenomena Inst, Athens, OH 45701 - USA
[6] Free Univ Berlin, Dahlem Ctr Complex Quantum Syst, D-14195 Berlin - Germany
[7] Free Univ Berlin, Fachbereich Phys, D-14195 Berlin - Germany
Total Affiliations: 7
Document type: Journal article
Source: Physical Review B; v. 87, n. 20 MAY 29 2013.
Web of Science Citations: 18
Abstract

We study the effect of a magnetic field in the Kondo regime of a double-quantum-dot system consisting of a strongly correlated dot (the ``side dot{''}) coupled to a second, noninteracting dot that also connects two external leads. We show, using the numerical renormalization group, that application of an in-plane magnetic field sets up a subtle interplay between electronic interference, Kondo physics, and Zeeman splitting with nontrivial-consequences for spectral and transport properties. The value of the side-dot spectral function at the Fermi level exhibits a nonuniversal field dependence that can be understood using a form of the Friedel sum rule that appropriately accounts for the presence of an energy-and spin-dependent hybridization function. The applied field also accentuates the exchange-mediated interdot coupling, which dominates the ground state at intermediate fields leading to the formation of antiparallel magnetic moments on the dots. By tuning gate voltages and the magnetic field, one can achieve complete spin polarization of the linear conductance between the leads, raising the prospect of applications of the device as a highly tunable spin filter. The system's low-energy properties are qualitatively unchanged by the presence of weak on-site Coulomb repulsion within the second dot. (AU)

FAPESP's process: 10/20804-9 - Electronic correlations and real-time dynamics in nanostructures: a computational approach
Grantee:Luis Gregório Godoy de Vasconcellos Dias da Silva
Support type: Regular Research Grants