| 1. |
- Goncąlves, C. S., et al.
(författare)
-
A Dual-Colour Architecture for Pump-Probe Spectroscopy of Ultrafast Magnetization Dynamics in the Sub-10-femtosecond Range
- 2016
-
Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 6
-
Tidskriftsartikel (refereegranskat)abstract
- Current time-resolution-limited dynamic measurements clearly show the need for improved techniques to access processes on the sub-10-femtosecond timescale. To access this regime, we have designed and constructed a state-of-the-art time-resolved magneto-optic Kerr effect apparatus, based on a new dual-color scheme, for the measurement of ultrafast demagnetization and precessional dynamics in magnetic materials. This system can operate well below the current temporal ranges reported in the literature, which typically lie in the region of around 50 fs and above. We have used a dual-colour scheme, based on ultra broadband hollow-core fibre and chirped mirror pulse compression techniques, to obtain unprecedented sub-8-fs pump and probe pulse durations at the sample plane. To demonstrate the capabilities of this system for ultrafast demagnetization and precessional dynamics studies, we have performed measurements in a ferrimagnetic GdFeCo thin film. Our study has shown that the magnetization shows a sudden drop within the first picosecond after the pump pulse, a fast recovery (remagnetization) within a few picoseconds, followed by a clear oscillation or precession during a slower magnetization recovery. Moreover, we have experimentally confirmed for the first time that a sub-10-fs pulse is able to efficiently excite a magnetic system such as GdFeCo.
|
|
| 2. |
- Gonçalves, C. S., et al.
(författare)
-
Ultrafast demagnetisation and precessional dynamics in GdFeCo thin Films using a new pump-probe system in the sub-8 femtosecond range
- 2019
-
Ingår i: Proceedings 2015 European Conference on Lasers and Electro-Optics - European Quantum Electronics Conference, CLEO/Europe-EQEC 2015. - 9781467374750
-
Konferensbidrag (refereegranskat)abstract
- New techniques capable of accessing ultrafast demagnetisation processes on the sub-10 femtosecond timescale are presently in great demand. Achieving a high temporal resolution in pump-probe time-resolved experiments is very important for studying ultrafast processes in matter, providing an ideal platform for understanding interaction mechanisms, such as the spin-orbit coupling, the exchange interaction, the structural anisotropy of the materials and the spin-phonon interaction, among others. These mechanisms are responsible for the modification of the magnetic order in nanostructures which are subject to an external perturbation on the temporal scale that extends from a few femtoseconds to the nanosecond regime
|
|
