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

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 ultra-high 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.

5 pages, 4 figures

References in corpus (5)

• Development of a Vacuum Ultra-Violet Laser-Based Angle-Resolved Photoemission System with a Super-High Energy Resolution Better Than 1 meV
• Identification of a New Form of Electron Coupling in Bi2Sr2CaCu2O8 Superconductor by Laser-Based Angle-Resolved Photoemission
• Experimental setup for low-energy laser-based angle resolved photoemission spectroscopy
• Unmasking the nodal quasiparticle dynamics in cuprate superconductors using low-energy photoemission
• Structure of BSCCO supermodulation from ab initio calculations

Cited by in corpus (2)

• Revealing the Coulomb interaction strength in a cuprate superconductor
• Time-resolved ARPES on cuprates: Tracking the low-energy electrodynamics in the time domain