Artículo
Ferromagnetic and underscreened Kondo behavior in quantum dot arrays
Fecha de publicación:
14/10/2015
Editorial:
American Physical Society
Revista:
Physical Review B: Condensed Matter and Materials Physics
ISSN:
0163-1829
e-ISSN:
1098-012
Idioma:
Inglés
Tipo de recurso:
Artículo publicado
Clasificación temática:
Resumen
We analyze the low energy properties of a device with N + 1 quantum dots in a star configuration. A central quantum dot is tunnel coupled to source and drain electrodes and to N quantum dots. Extending previous results for the N = 2 case we show that, in the appropriate parameter regime, the low energy Hamiltonian of the system is a ferromagnetic Kondo model for a S = (N −1)/2 impurity spin. For small enough interdot tunnel coupling, however, a two-stage Kondo effect takes place as the temperature is decreased. The spin 1/2 in the central quantum dot is Kondo screened first and at lower temperatures the antiferromagnetic coupling to the side-coupled quantum dots leads to an underscreened S = N/2 Kondo effect. We present numerical results for the thermodynamic and spectral properties of the system which show a singular behavior at low temperatures and allow to characterize the different strongly correlated regimes of the device.
Palabras clave:
Quantum dot
,
Kondo effect
,
underscreened Kondo
,
Ferromagnetic Kondo
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Articulos(CCT - PATAGONIA NORTE)
Articulos de CTRO.CIENTIFICO TECNOL.CONICET - PATAGONIA NORTE
Articulos de CTRO.CIENTIFICO TECNOL.CONICET - PATAGONIA NORTE
Citación
Andrade Hoyos, Jhon Alejandro; Garcia, Daniel Julio; Cornaglia de la Cruz, Pablo Sebastian; Ferromagnetic and underscreened Kondo behavior in quantum dot arrays; American Physical Society; Physical Review B: Condensed Matter and Materials Physics; 92; 165416; 14-10-2015; 1-8
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