Dynamical screening and plasmonic replica bands in SrVO 3

Le résumé fourni par la source

SrVO 3 has long been considered a prototype for studying electronic correlations due to its simple electronic structure and coherent t 2 g quasiparticle band. However, the origin of the incoherent satellite at 1.5 eV binding energy seen in photoemission remains enigmatic, having been attributed to Hubbard physics, oxygen vacancies, or plasmonic coupling. Here, we investigate the t 2 g band and satellite feature in epitaxially strained thin films of SrVO 3 using angle-resolved photoemission spectroscopy. We observe an increase in the quasiparticle effective mass due to tensile strain as a result of the narrowing of the corresponding bandwidth. While a low-energy kink at 60 meV indicates additional electron-phonon interactions, no strain-dependent behavior is detected. The increased effective mass coincides with a decrease in the plasma frequency from reported ellipsometry measurements and theoretical calculations. From this, we associate the plasma frequency with the quasiparticle-satellite energy separation that follows the same strain-induced changes. This consistency affirms the identification of the satellite feature as a replica band due to coherent coupling between quasiparticles and low-energy plasmons and emphasizes the role of dynamical screening as a key organizing principle in the electronic structure of correlated oxides.

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