Spin chirality fluctuations and anomalous Hall effect in itinerant ferromagnets.
The anomalous Hall effect due to the spin chirality order and fluctuation is studied theoretically in a Kondo lattice model without the relativistic spin-orbit interaction. Even without the correlations of the localized spins, sigma(xy) can emerge depending on the lattice structure and the spin anisotropy. We reveal the condition for this chirality-fluctuation driven mechanism for sigma(xy). Our semiquantitative estimates for a pyrochlore oxide Nd2Mo2O7 give a finite sigma(xy) approximately equal 10 Omega(-1) cm(-1) together with a high resistivity rho(xx) approximately equal 10(-4)-10(-3) Omega cm, in agreement with experiments.
Onoda
Shigeki
S
Tokura Spin Superstructure Project, ERATO, Japan Science and Technology Corporation, c/o Department of Applied Physics, University of Tokyo, Tokyo 113-8656, Japan.
Nagaosa
Naoto
N