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

Research output: Contribution to journalArticleScientificpeer-review

Details

Original languageEnglish
Article number085109
Number of pages5
JournalPhysical Review B
Volume91
Issue number8
DOIs
Publication statusPublished - 13 Feb 2015
Publication typeA1 Journal article-refereed

Abstract

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.

Publication forum classification

Field of science, Statistics Finland