305 research outputs found
Anomalous Hall effect and weak localization corrections in a ferromagnet
In this paper, we report results on the anomalous Hall effect. First, we
summarize analytical calculations based on the Kubo formalism : explicit
expressions for both skew-scattering and side-jump are derived and
weak-localization corrections are discussed. Next, we present numerical
calculations of the anomalous Hall resistivity based on the Dirac equation.
Qualitative agreement with experiments is obtained.Comment: Proceeding JEMS'0
Spin relaxation related to the edge scattering in graphene
We discuss the role of spin-flip scattering of electrons from the magnetized
edges in graphene nanoribbons. The spin-flip scattering is associated with
strong fluctuations of the magnetic moments at the edge. Using the Boltzmann
equation approach, which is valid for not too narrow nanoribbons, we calculate
the spin relaxation time in the case of Berry-Mondragon and zigzag graphene
edges. We also consider the case of ballistic nanoribbons characterized by very
long momentum relaxation time in the bulk, when the main source of momentum and
spin relaxation is the spin-dependent scattering at the edges. We found that in
the case of zigzag edges, an anomalous spin diffusion is possible, which is
related to very weak spin-flip scattering of electrons gliding along the
nanoribbon edge.Comment: 9 pages, 7 figure
Anomalous Hall effect in ferromagnetic disordered metals
The anomalous Hall effect in disordered band ferromagnets is considered in
the framework of quantum transport theory. A microscopic model of electrons in
a random potential of identical impurities including spin-orbit coupling is
used. The Hall conductivity is calculated from the Kubo formula for both, the
skew scattering and the side-jump mechanisms. The recently discussed Berry
phase induced Hall current is also evaluated within the model. The effect of
strong impurity scattering is analyzed and it is found to affect the ratio of
the non-diagonal (Hall) and diagonal components of the conductivity as well as
the relative importance of different mechanisms.Comment: Invited paper for Ann. Physik commemorating Paul Drud
- …