Local and non-local electron dynamics of Au/Fe/MgO(001) heterostructures analyzed by time-resolved two-photon photoemission spectroscopy

Autor: Beyazit, Yasin, Beckord, Jan, Zhou, Ping, Meyburg, Jan, Diesing, Detlef, Ligges, Manuel, Bovensiepen, Uwe
Rok vydání: 2019
Předmět:
Zdroj: Phys. Rev. Lett. 125, 076803 (2020)
Druh dokumentu: Working Paper
DOI: 10.1103/PhysRevLett.125.076803
Popis: Employing femtosecond laser pulses in front and back side pumping of Au/Fe/MgO(001) combined with detection in two-photon photoelectron emission spectroscopy we analyze local relaxation dynamics of excited electrons in buried Fe, injection into Au across the Fe-Au interface, and electron transport across the Au layer at 0.6 to 2.0 eV above the Fermi energy. By analysis as a function of Au film thickness we obtain the electron lifetimes of bulk Au and Fe and distinguish the relaxation in the heterostructure's constituents. We also show that the excited electrons propagate through Au in a superdiffusive regime and conclude further that electron injection across the epitaxial interface proceeds ballistically by electron wavepacket propagation.
Comment: 5 pages, 4 figures
Databáze: arXiv