Ab initio theory of electron-phonon mediated ultrafast spin relaxation of laser-excited hot electrons in transition-metal ferromagnets
2013 (English)In: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 87, no 18, 184425- p.Article in journal (Refereed) Published
We report a computational theoretical investigation of electron spin-flip scattering induced by the electron-phonon interaction in the transition-metal ferromagnets bcc Fe, fcc Co, and fcc Ni. The Elliott-Yafet electron-phonon spin-flip scattering is computed from first principles, employing a generalized spin-flip Eliashberg function as well as ab initio computed phonon dispersions. Aiming at investigating the amount of electron-phonon mediated demagnetization in femtosecond laser-excited ferromagnets, the formalism is extended to treat laser-created thermalized as well as nonequilibrium, nonthermal hot electron distributions. Using the developed formalism we compute the phonon-induced spin lifetimes of hot electrons in Fe, Co, and Ni. The electron-phonon mediated demagnetization rate is evaluated for laser-created thermalized and nonequilibrium electron distributions. Nonthermal distributions are found to lead to a stronger demagnetization rate than hot, thermalized distributions, yet their demagnetizing effect is not enough to explain the experimentally observed demagnetization occurring in the subpicosecond regime.
Place, publisher, year, edition, pages
2013. Vol. 87, no 18, 184425- p.
IdentifiersURN: urn:nbn:se:uu:diva-203293DOI: 10.1103/PhysRevB.87.184425ISI: 000319280800002OAI: oai:DiVA.org:uu-203293DiVA: diva2:636185