Magnetic and transport properties of the one-dimensional ferromagnetic Kondo lattice model with an impurity

S. COSTAMAGNA; J. A. RIERA

PHYSICAL REVIEW B - CONDENSED MATTER AND MATERIALS PHYSICS

Año: 2008 vol. 77 p. 1 - 7

0163-1829

   We have studied the ferromagnetic Kondo lattice model FKLM with an Anderson impurity on finite chainswith numerical techniques. We are particularly interested in the metallic ferromagnetic phase of the FKLM.This model could describe either a quantum dot coupled to one-dimensional ferromagnetic leads made withmanganites or a substitutional transition metal impurity in a MnO chain. We determined the region in param-eter space where the impurity is empty, half filled, or doubly occupied and, hence, where it is magnetic ornonmagnetic. The most important result is that we found, for a wide range of impurity parameters and electrondensities where the impurity is magnetic, a singlet phase located between two saturated ferromagnetic phaseswhich correspond approximately to the empty and doubly occupied impurity states. Transport propertiesbehave, in general, as expected as a function of the impurity occupancy, and they provide a test for a recentlydeveloped numerical approach to compute the conductance. The results obtained could be, in principle, repro-duced experimentally in already existent related nanoscopic devices or in impurity doped MnO nanotubes.