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

Article

关键词: ULTRAVIOLET PHOTOEMISSION;    REFLECTION;    ENERGY;    TRANSMISSION;    SPECTRA;    RU(001);    SURFACE;   

DOI  :  10.1103/PhysRevB.91.085109

来源: SCIE

【 摘 要 】

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.

【 授权许可】

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