Quantized Transport in Two-Dimensional Spin-Ordered Structures

Ilaria Campana (1) , Giancarlo Jug (2) , Klaus Ziegler (3)

1 Physik
2 Mathematics and Physics
3 Physik

We study in detail the transport properties of a model of conducting electrons in the presence of double-exchange between localized spins arranged on a 2D Kagome lattice, as introduced by Ohgushi, Murakami and Nagaosa (2000). The relationship between the canting angle of the spin texture $\theta$ and the Berry phase field flux per triangular plaquette $\phi$ is derived explicitly and we emphasize the similarities between this model and Haldane's honeycomb lattice version of the quantum Hall effect (Haldane, 1988). The quantization of the transverse (Hall) conductivity $\sigma_{xy}$ is derived explicitly from the Kubo formula and a direct calculation of the longitudinal conductivity $\sigma_{xx}$ shows the existence of a metal-insulator transition as a function of the canting angle $\theta$ (or flux density $\phi$). This transition might be linked to that observable in the manganite compounds or in the pyrochlore ones, as the spin ordering changes from ferromagnetic to canted.

Mots clés: Physical Sciences

Ilaria Campana, Giancarlo Jug, Klaus Ziegler. Quantized Transport in Two-Dimensional Spin-Ordered Structures. Philosophical Magazine, 2006, 86 (12), pp.1667-1687. ⟨10.1080/14786430500499363⟩. ⟨hal-00513643⟩