English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

Understanding the microscopic spatio-temporal dynamics of nonequilibriumcharge carriers in heterosystems promises optimization of process and devicedesign towards desired energy transfer. Hot electron transport is governed byscattering with other electrons, defects, and bosonic excitations. Analysis ofthe energy dependence of scattering pathways and identification of diffusive,super-diffusive, and ballistic transport regimes are current challenges. Wedetermine in femtosecond time-resolved two-photon photoelectron emissionspectroscopy the energy-dependent change of the electron propagation timethrough epitaxial Au/Fe(001) heteostructures as a function of Au layerthickness for energies of 0.5 to \unit[2.0]{eV} above the Fermi energy. Wedescribe the laser-induced nonequilibrium electron excitation and injectionacross the Fe/Au interface using real-time time-dependent density functionaltheory and analyze the electron propagation through the Au layer by microscopicelectron transport simulations. We identify ballistic transport of minorityelectrons at energies with a nascent, optically excited electron populationwhich is determined by the combination of photon energy and the specificelectronic structure of the material. At lower energy, super-diffusivetransport with 1 to 4 scattering events dominates. The effective electronvelocity accelerates from 0.3 to \unit[1]{nm/fs} with an increase in the Aulayer thickness from 10 to 100~nm. This phenomenon is explained by electrontransport that becomes preferentially aligned with the interface normal forthicker Au layers, which facilitates electron momentum / energy selection bychoice of the propagation layer thickness.

Spatio-Temporal Electron Propagation Dynamics in Au/Fe/MgO(001) in nonequilibrium: Revealing Single Scattering Events and the Ballistic Limit