Non-Fermi-liquid behavior in nonequilibrium transport through Co-doped Au chains connected to fourfold symmetric leads

We calculate the differential conductance as a function of temperature and bias voltage, G(T ,V ), through Au monatomic chains with a substitutional Co atom as a magnetic impurity, connected to a fourfold symmetric lead. The system was recently proposed as a possible scenario for observation of the...

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Detalles Bibliográficos
Autores: Di Napoli, Solange Mariel, Roura Bas, Pablo Gines, Weichselbaum, Andreas, Aligia, Armando Ángel
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2014
País:Argentina
Institución:Consejo Nacional de Investigaciones Científicas y Técnicas
Repositorio:CONICET Digital (CONICET)
Idioma:inglés
OAI Identifier:oai:ri.conicet.gov.ar:11336/32854
Acceso en línea:http://hdl.handle.net/11336/32854
Access Level:acceso abierto
Palabra clave:KONDO PHYSICS
NON-EQUILIBRIUM TRANSPORT
NCA
NRG
https://purl.org/becyt/ford/1.3
https://purl.org/becyt/ford/1
Descripción
Sumario:We calculate the differential conductance as a function of temperature and bias voltage, G(T ,V ), through Au monatomic chains with a substitutional Co atom as a magnetic impurity, connected to a fourfold symmetric lead. The system was recently proposed as a possible scenario for observation of the overscreened Kondo physics. Stretching the chain, the system could be tuned through a quantum critical point (QCP) with three different regimes: overscreened, underscreened, and non-Kondo phases. We present calculations of the impurity spectral function by using the numerical renormalization group for the three different regimes characterizing the QCP. Nontrivial behavior of the spectral function is reported near the QCP. Comparison with results using the noncrossing approximation (NCA) shows that the latter is reliable in the overscreened regime, when the anisotropy is larger than the Kondo temperature. For these parameters, which correspond to realistic previous estimates, G(T,V) calculated within NCA exhibits clear signatures of the non-Fermi-liquid behavior within the overscreened regime.