Speaker
Description
Magnetization reversal, spin transfer torque, giant magnetoresistance [1] and the emission of terahertz (THz) radiation [2] are intriguing spintronic applications. They all require controlled generation and manipulation of spin currents. Promising candidates to generate spin currents for high speed spin information processing are the anomalous and spin Hall effects (AHE, SHE), whose inverse were demonstrated recently up to THz frequencies [3]. However, no direct observation of AHE-related ultrafast spin accumulation at sample interfaces has been reported so far.
In this contribution, the interaction of ultrashort intense Pulses of THz radiation with metallic thin film samples is studied. A strong THz electric field (up to ~0.5 MV/cm) is used to drive ultrafast charge currents in the plane of the sample. By means of the magnetooptic Kerr effect, we investigate the ultrafast spin and charge redistribution in thin films due to such excitation and the AHE currents.
References
[1] C. Chappert, A. Fert, Frédéric Nguyen Van Dau, Nature Materials 6, 813-823 (2007).
[2] T. Kampfrath et al., Nature Nanotech. 8, 256 (2013).
[3] T. Seifert, M. Wolf, T. Kampfrath et al., Nature Photon. 10, 483 (2016).