1999/10/31 by R. Knorren, K. H. Bennemann, R. Burgermeister +2 · 176 citations
Materials Science · Physics and Astronomy · #Advanced Chemical Physics Studies #Atomic physics #Condensed matter physics #Electron #Electron and X-Ray Spectroscopy Techniques #Excited state #Ferromagnetism #Magnetic properties of thin films #Photoexcitation #Physics #Quantum mechanics #Relaxation (psychology) #cond-mat
paper · pdf · doi:10.1103/physrevb.61.9427
published in Physical review. B, Condensed matter 61(14), 9427-9440 (American Physical Society) · 23 pages, 11 figures, added a figure and an appendix, updated references
arxiv created 2000/02/19 · openalex publication_date 2000/04/01 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Both theoretical and experimental results for the dynamics of photoexcited electrons at surfaces of Cu and the ferromagnetic transition metals Fe, Co, and Ni are presented. A model for the dynamics of excited electrons is developed, which is based on the Boltzmann equation and includes effects of photoexcitation, electron-electron scattering, secondary electrons (cascade and Auger electrons), and transport of excited carriers out of the detection region. From this we determine the time-resolved two-photon photoemission (TR-2PPE). Thus a direct comparison of calculated relaxation times with experimental results by means of TR-2PPE becomes possible. The comparison indicates that the magnitudes of the spin-averaged relaxation time \ensuremathτ and of the ratio \ensuremathτ_\ensuremath\uparrow/\ensuremathτ_\ensuremath\downarrow of majority and minority relaxation times for the different ferromagnetic transition metals result not only from density-of-states effects, but also from different Coulomb matrix elements M. Taking MFe>MCu>MNi=MCo we get reasonable agreement with experiments.