info:eu-repo/semantics/article
Quantum entanglementin elliptical quantum corrals
Fecha
2009-10Registro en:
Nizama Mendoza, Marco Alfredo; Frustaglia, D.; Hallberg, Karen Astrid; Quantum entanglementin elliptical quantum corrals; Elsevier Science; Physica B: Condensed Matter; 404; 18; 10-2009; 2819-2821
0921-4526
CONICET Digital
CONICET
Autor
Nizama Mendoza, Marco Alfredo
Frustaglia, D.
Hallberg, Karen Astrid
Resumen
Quantum corrals present interesting properties due to the combination of confinement and, in the case of elliptical corrals, to their focalizing properties. We study the case when two magnetic impurities are added to the non-interacting corral, where they interact via a superexchange AF interaction J with the surface electrons in the ellipse. Previous results showed that, when both impurities are located at the foci of the system, they experience an enhanced magnetic interaction, as compared to the one they would have in an open surface. For small J and even filling, they are locked in a singlet state, which weakens for larger values of this parameter. When J is much larger than the hopping parameter of the electrons in the ellipse, both spins decorrelate while forming a local singlet with the electrons of the ellipse, thus presenting a confined RKKY-Kondo transition. We interpret this behaviour by means of the von Neumann entropy between the localized impurities and the itinerant electrons of the ellipse: for small J the entropy is nearly zero while for large J it is maximum. In addition, the local density of states provides us with a concrete experimental tool for detecting the Kondo regime.