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Spin-flip processes and ultrafast magnetization dynamics in Co - unifying the microscopic and macroscopic view of femtosecond magnetism

M. Cinchetti·M. Sánchez Albaneda·D. Hoffmann·T. Roth·J. -P. Wüstenberg·M. Krauß·O. Andreyev·H. C. Schneider·M. Bauer·M. Aeschlimann
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Abstract

The femtosecond magnetization dynamics of a thin cobalt film excited with ultrashort laser pulses has been studied using two complementary pump-probe techniques, namely spin-, energy- and time-resolved photoemission and time-resolved magneto-optical Kerr effect. Combining the two methods it is possible to identify the microscopic electron spin-flip mechanisms responsible for the ultrafast macroscopic magnetization dynamics of the cobalt film. In particular, we show that electron-magnon excitation does not affect the overall magnetization even though it is an efficient spin-flip channel on the sub-200 fs timescale. Instead we find experimental evidence for the relevance of Elliott-Yafet type spin-flip processes for the ultrafast demagnetization taking place on a time scale of 300 fs.

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M. Cinchetti, M. Sánchez Albaneda, D. Hoffmann, T. Roth, J. -P. Wüstenberg, M. Krauß, O. Andreyev, H. C. Schneider, M. Bauer, M. Aeschlimann. 2006-10-03. Spin-flip processes and ultrafast magnetization dynamics in Co - unifying the microscopic and macroscopic view of femtosecond magnetism. https://doi.org/10.1103/physrevlett.97.177201

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