Berlin 2018 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 46: Magnonics II

MA 46.10: Vortrag

Donnerstag, 15. März 2018, 17:30–17:45, H 0110

Phonon-pulse-induced magnetization dynamics in magnetic tunnel junctions — •Hangfu Yang, Xiukun Hu, Sibylle Sievers, Mark Bieler, and Hans W. Schumacher — Physikalisch-Technische Bundesanstalt, Bundesallee 100, 38116 Braunschweig, Germany.

Manipulating the angular momentum of spins with external stimulus is a key issue in the field of spintronic with the aim to boost logic and memory applications. Here, we report time-domain measurements of magnetization dynamics in magnetic tunnel junctions (MTJs) driven by femtosecond-laser-induced phonon pulses through the inverse magnetostriction effect. The precession frequency is strongly dependent on amplitude and angle of the applied magnetic field. We find that the phonon-induced precession frequency differs from the precession frequency triggered by spin transfer torque. Most likely this is due to a spatially nonuniform precession mode excitation of the MTJ by the phonon pulses. Furthermore, we demonstrate coherent control of magnetization precession using two laser pulses at various magnetic fields and heating positions.