Fyzikální ústav Akademie věd ČR

Seminář Úterý, 15.02.2011 15:00 - 16:00

Přednášející: Pavel Středa (Oddělení polovodičů, Fyzikální ústav AV ČR)
Místo: Na Slovance, main lecture room
Pořadatelé:
   Oddělení teorie kondenzovaných látek
Jazyk: česky

Abstract: A review of general features of the anomalous Hall conductivity observed on ferromagnetic systems followed by a theory (Kubo formula) based on the space distribution of the current densities will be presented. It is argued that intrinsic anomalous conductivity is determined by the Berry phase correction to the orbital momentum of Fermi electrons. It is the part of the momentum responsible for a local charge polarization induced by the applied current. Effect of the disorder is modeled by energy fluctuations of atomic-like orbitals included by the use of the single-site approach. Presented two-band model of a ferromagnetic system gives by the unified way experimentally observed qualitative features of the anomalous Hall conductivity in the regimes showing universal behavior, especially its scaling with longitudinal conductivity. For intrinsic, scattering independent, anomalous Hall conductivity Drude-Zener type formula will be derived.