We study THz-driven spin dynamics in thin CoPt films with perpendicular magnetic anisotropy. Femtosecond magneto-optical Kerr effect measurements show that demagnetization amplitude of about 1% can be achieved with a peak THz electric field of 300 kV cm-1, and a corresponding peak magnetic field of 0.1 T. The effect is more than an order of magnitude larger than observed in samples with easy-plane anisotropy irradiated with the same field strength. We also utilize finite-element simulations to design a meta-material structure that can enhance the THz magnetic field by more than an order of magnitude, over an area of several tens of square micrometers. Magnetic fields exceeding 1 Tesla, generated in such meta-materials with the available laser-based THz sources, are expected to produce full magnetization reversal via ultrafast ballistic precession driven by the THz radiation. Our results demonstrate the possibility of table-top ultrafast magnetization reversal induced by THz radiation.
Autori: | Bonetti, Stefano (Corresponding) |
Data di pubblicazione: | 2018 |
Titolo: | THz-driven demagnetization with perpendicular magnetic anisotropy: Towards ultrafast ballistic switching |
Rivista: | JOURNAL OF PHYSICS D. APPLIED PHYSICS |
Digital Object Identifier (DOI): | http://dx.doi.org/10.1088/1361-6463/aaa863 |
Volume: | 51 |
Appare nelle tipologie: | 2.1 Articolo su rivista |