2018/01/31 by Cheng‐Tai Kuo, Cheng-Tai Kuo, Shih‐Chieh Lin +27 · 1 citation
Chemistry · Physics and Astronomy · #Advanced Chemical Physics Studies #Advanced Condensed Matter Physics #Angle-resolved photoemission spectroscopy #Atomic physics #Chemistry #Condensed matter physics #Crystallography #Cuprate #Electronic structure #Excitation #Materials science #Physics #Physics of Superconductivity and Magnetism #Quantum mechanics #Superconductivity #Valence (chemistry) #cond-mat.mtrl-sci #cond-mat.str-el #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevb.98.155133
published as Phys. Rev. B 98, 155133 (2018) · 22 pages, 5 figures, plus Supplemental Material (15 pages)
arxiv created 2018/09/24 · openalex publication_date 2018/10/19 · arxiv updated 2018/10/22 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
A major remaining challenge in the superconducting cuprates is the unambiguous differentiation of the composition and electronic structure of the CuO2 layers and those of the intermediate layers. The large c axis for these materials permits employing soft x-ray (930.3 eV) standing wave (SW) excitation in photoemission that yields atomic layer-by-layer depth resolution of these properties. Applying SW photoemission to Bi2Sr2CaCu2O_8+\ensuremathδ yields the depth distribution of atomic composition and the layer-resolved densities of states. We detect significant Ca presence in the SrO layers and oxygen bonding to three different cations. The layer-resolved valence electronic structure is found to be strongly influenced by the atomic supermodulation structure, as determined by comparison to density functional theory calculations, by Ca-Sr intermixing, and by correlation effects associated with the Cu 3d\text\ensuremath-3d Coulomb interaction, further clarifying the complex interactions in this prototypical cuprate. Measurements of this type for other quasi-two-dimensional materials with large c represent a promising future direction.