Sub 100-ps dynamics of the anomalous Hall effect at THz frequencies
  We report about the anomalous Hall effect in 4f 3d metallic alloys measured using terahertz time-domain spectroscopy. The strength of the observed terahertz spin-dependent transport phenomenon is in good agreement with expectations based on electronic transport measurements. Employing this effect, we succeeded to reveal ultrafast dynamics of the anomalous Hall effect which accompanies the sub-100 picosecond optically induced magnetization reversal in a GdFeCo alloy. The experiments demonstrate the ability to control currents at terahertz frequencies in spintronic devices magnetically and ultrafast. 
T. J. Huisman, R. V. Mikhaylovskiy, A. Tsukamoto, L. Ma, W. J. Fan, S.   M. Zhou, Th. Rasing and A. V. Kimel
cond-mat.mes-hall cond-mat.mtrl-sci physics.optics