Numerical study of finite size effects in the one-dimensional two-impurity Anderson model

S. COSTAMAGNA; J. A. RIERA

PHYSICAL REVIEW B - CONDENSED MATTER AND MATERIALS PHYSICS

Año: 2008 vol. 77 p. 1 - 5

0163-1829

   We study the two-impurity Anderson model on finite chains using numerical techniques. We discuss thedeparture of magnetic correlations as a function of the interimpurity distance from a pure 2kF oscillation dueto open boundary conditions. We observe qualitatively different behaviors in the interimpurity spin correlationsand in transport properties at different values of the impurity couplings. We relate these different behaviors toa change in the relative dominance between the Kondo effect and the Ruderman-Kittel-Kasuya-Yoshida RKKY interaction. We also observe that when RKKY dominates, there is a definite relation between inter-impurity magnetic correlations and transport properties. In this case, there is a recovery of 2kF periodicitywhen the on-site Coulomb repulsion on the chain is increased at quarter filling. The present results could berelevant for electronic nanodevices implementing a nonlocal control between two quantum dots that could belocated at variable distance along a wire.