Abstract-Sub-100-ps dynamics of the anomalous Hall effect at terahertz frequencies

T. J. Huisman, R. V. Mikhaylovskiy, Th. Rasing, A. V. Kimel, A. Tsukamoto, B. de Ronde, L. Ma, W. J. Fan, and S. M. Zhou

Phys. Rev. B 95, 094418 – Published 13 March 2017

https://journals.aps.org/prb/abstract/10.1103/PhysRevB.95.094418

We report about the anomalous Hall effect in $4f3d$ metallic alloys measured using terahertz time-domain spectroscopy. In this way, we succeeded in revealing ultrafast dynamics of the anomalous Hall effect which accompanies the sub-100-ps 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.

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Abstract-Simultaneous measurements of terahertz emission spectroscopy and magneto-optical Kerr effect for resolving ultrafast laser-induced demagnetization dynamics

Phys. Rev. B

T. J. Huisman, R. V. Mikhaylovskiy, A. Tsukamoto, Th. Rasing, and A. V. Kimel

http://journals.aps.org/prb/accepted/30073YdcM281a444f2e17ea6e5e5e22915021bb26

Simultaneous detection of THz emission and transient magneto-optical response is employed to study ultrafast laser-induced magnetization dynamics in three different types of amorphous metallic alloys: Co, GdFeCo and NdFeCo. A satisfactory agreement between the dynamics revealed with the help of these two techniques is obtained for Co and GdFeCo. For NdFeCo the THz emission indicates faster dynamics than the magneto-optical response. This observation indicates that in addition to spin dynamics of Fe, ultrafast laser excitation of NdFeCo triggers faster magnetization dynamics of Nd originating from its orbital momentum.