IFIR   05409
INSTITUTO DE FISICA DE ROSARIO
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Influence of spin correlations in the transport properties of a double quantum dot system
Autor/es:
I. J. HAMAD; L. COSTA RIBEIRO; G. CHIAPPE; E. V. ANDA
Lugar:
Baltimore
Reunión:
Congreso; APS March Meeting 2013; 2013
Institución organizadora:
American Physical Society
Resumen:
In this work we study the influence of spin
correlations in the transport properties of a system consisting of two
quantum dots (QDs) with high Coulomb interaction U which are
interconnected through a chain of N non-interacting sites and
individually coupled to two metallic leads. Using both the finite U
slave boson mean field approach (FUSBMFA) and the
Logarithmic-discretization-embedded-cluster approximation (LDECA) we
studied the system in different regions of the parameter space for which
we calculate many physical quantities, namely local density of states,
conductance, total spin, spin correlations, in addition to the
renormalization parameters associated with the FUSBMFA. The results
reveled a very rich physical scenario which is manifested by at least
two different Kondo regimes, the well-known spin s = 1/2 and some other
type of Kondo effect which appears as a result of the coupling between
the QDs and the non-interacting central sites. We also consider the
possibility of accessing some kind of Kondo box effect due to the
discrete nature of the central chain and study how this regime is
affected by the magnetic interaction between the local spins of the QD's
and by the interaction between these spins and the spins of the
conduction electros in the leads.