Early Stages of Ultrafast Spin Dynamics in a 3d Ferromagnet
| Autor: | A.W. Fognini, Thomas Michlmayr, Nadja Hartmann, Rafael Gort, Gerard Salvatella, C. Stieger, Yannik Zemp, Kevin Bühlmann, T. Bahler, Simon Däster, Yves Acremann, Stefan Holenstein, Andreas Vaterlaus |
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| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
Physics
Spin polarization Condensed matter physics Spins General Physics and Astronomy Physics::Optics Fermi energy 02 engineering and technology 021001 nanoscience & nanotechnology 01 natural sciences Magnetization Ferromagnetism Lattice (order) 0103 physical sciences Femtosecond Condensed Matter::Strongly Correlated Electrons 010306 general physics 0210 nano-technology Fermi gas |
| Zdroj: | Physical Review Letters, 121(8) Physical Review Letters, 121 (8) |
| ISSN: | 0031-9007 |
| Popis: | Prior to the development of pulsed lasers, one assigned a single local temperature to the lattice, the electron gas, and the spins. With the availability of ultrafast laser sources, one can now drive the temperature of these reservoirs out of equilibrium. Thus, the solid shows new internal degrees of freedom characterized by individual temperatures of the electron gas ${T}_{e}$, the lattice ${T}_{l}$ and the spins ${T}_{s}$. We demonstrate an analogous behavior in the spin polarization of a ferromagnet in an ultrafast demagnetization experiment: At the Fermi energy, the polarization is reduced faster than at deeper in the valence band. Therefore, on the femtosecond time scale, the magnetization as a macroscopic quantity does not provide the full picture of the spin dynamics: The spin polarization separates into different parts similar to how the single temperature paradigm changed with the development of ultrafast lasers. |
| Databáze: | OpenAIRE |
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