A Dual-Colour Architecture for Pump-Probe Spectroscopy of Ultrafast Magnetization Dynamics in the Sub-10-femtosecond Range

• Tipo: Artigo em Revista Científica Internacional
• Data: 2016

Autores

Goncalves, CS (Autor) Outra; Silva, AS (Autor) Outra; Navas, D (Autor) Outra; Miranda, M (Autor) Outra; Silva, F (Autor) Outra; Crespo, H (Autor) FCUP; Schmool, DS (Autor) Outra

Revista

Título: Scientific Reports

Vol. 6

Página Final: 22872

ISSN: 2045-2322

Editora: Springer Nature

Indexação

ISI Web of Knowledge - 8 Citações

Scopus - 9 Citações

Outras Informações

ID Authenticus: P-00K-B0F

DOI: 10.1038/srep22872

Abstract (EN): 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.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 11