Mass modification of itinerant carriers in RKKY oscillations induced by finite-range exchange interactions

Abstract

We investigate the Ruderman-Kittel-Kasuya-Yosida oscillations of the itinerant carrier spin density in a system where those oscillations appear only due to a finite distribution of a localized spin. The system represents a half-infinite one-dimensional quantum wire with a magnetic impurity located at its edge. In contrast to the conventional model of a pointlike exchange interaction the itinerant carrier spin-density oscillations in this system exist. We analytically demonstrate that when the radius of the exchange interaction is less than the wavelength of the itinerant carriers living on the Fermi surface, the long-range behavior of the oscillations is identical to the one taking place in the zero-radius limit of the same exchange interaction but for an infinite one-dimensional quantum wire where, in comparison with the original half-infinite system, the mass of the itinerant carriers is strongly modified by the exchange interaction radius. On the basis of our analysis we make a suggestion on directionality of surface Ruderman-Kittel-Kasuya-Yosida interaction shown in recent experiments: we believe that in general the anisotropy of the Ruderman-Kittel-Kasuya-Yosida interaction could result not only from the anisotropy of the Fermi surface of itinerant carriers but also from the anisotropy of the spin carrying atomic orbitals of magnetic impurities.

Evolution of the multiband Ruderman–Kittel–Kasuya–Yosida interaction: application to iron pnictides and chalcogenides

“…The real overlap of the conduction electron and localized 4f electron wave functions and, therefore, I (R − R i ), in general, is non-zero in a finite volume around the 4f site R i . This leads to a damping in the effective intersite coupling energies [39][40][41]. For simplicity, we use here the common approximation of an on-site exchange interaction which can be approximated as…”

Gate-tunable indirect exchange interaction in spin-orbit–coupled mesoscopic rings

“…There are a few studies about the interplay between SOI and the RKKY interaction [12][13][14][15][16][17][18][19][20][21][22][23][24]. We consider a mesoscopic ring formed in the two-dimensional electron gas (2DEG) trapped in a quantum well at the interface of a semiconductor heterojunction.…”