TUTCRIS - Tampereen teknillinen yliopisto

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Resolving unoccupied electronic states with laser ARPES in bismuth-based cuprate superconductors

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Yksityiskohdat

AlkuperäiskieliEnglanti
Artikkeli085109
Sivumäärä5
JulkaisuPhysical Review B
Vuosikerta91
Numero8
DOI - pysyväislinkit
TilaJulkaistu - 13 helmikuuta 2015
OKM-julkaisutyyppiA1 Alkuperäisartikkeli

Tiivistelmä

Angle-resolved photoemission spectroscopy (ARPES) is typically used to study only the occupied electronic band structure of a material. Here we use laser-based ARPES to observe a feature in bismuth-based superconductors that, in contrast, is related to the unoccupied states. Specifically, we observe a dispersive suppression of intensity cutting across the valence band, which, when compared with relativistic one-step calculations, can be traced to two final-state gaps in the bands 6 eV above the Fermi level. This finding opens up possibilities to bring the ultrahigh momentum resolution of existing laser-ARPES instruments to the unoccupied electron states. For cases where the final-state gap is not the object of study, we find that its effects can be made to vanish under certain experimental conditions.

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