Ultrafast Spin Dynamics of Ferromagnetic Thin Films Observed by fs Spin-Resolved Two-Photon Photoemission

Autor:	Andreas Scholl, Wolfgang Eberhardt, R. Jacquemin, L. Baumgarten
Rok vydání:	1997
Předmět:	Materials science Condensed matter physics Magnetic moment Spin polarization Scattering Excited state Spinplasmonics General Physics and Astronomy Condensed Matter::Strongly Correlated Electrons Electron Spin (physics) Excitation
Zdroj:	Physical Review Letters. 79:5146-5149
ISSN:	1079-7114 0031-9007
DOI:	10.1103/physrevlett.79.5146
Popis:	Using a ``pump and probe'' technique, the time scale of spin relaxation effects in ferromagnetic thin films is investigated. Samples are excited by a 3 eV ``pump'' laser pulse $(\ensuremath{\tau}\ensuremath{\approx}170\mathrm{fs})$, and electrons are photoemitted by a 6 eV ``probe'' pulse, after delays ranging up to 1 ns. The spin polarization of the photoelectrons is measured using a Mott detector. The time dependence of the spin polarization of thin Ni films on Ag is explained in a local magnetic moment picture with two excitation processes. Stoner excitations are responsible for the reduction of the observed spin polarization on a time scale of 1 ps and phonon-magnon scattering leads to the loss of long range magnetic order on a time scale of 500 ps.
Databáze:	OpenAIRE
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