2011/08/25 by Jamil Tahir-Kheli, Jamil Tahir‐Kheli, William A. Goddard III +1 · 21 citations
Physics and Astronomy · #Advanced Condensed Matter Physics #Condensed matter physics #Cuprate #Dopant #Doping #Electron #Fermi level #Magnetic properties of thin films #Materials science #Pairing #Physics #Physics of Superconductivity and Magnetism #Pseudogap #Quantum mechanics #Superconductivity #cond-mat.mtrl-sci #cond-mat.str-el #cond-mat.supr-con
paper · pdf · doi:10.1021/jz200916t
published in The Journal of Physical Chemistry Letters 2(18), 2326-2330 (American Chemical Society) · 24 pages (4 pages main text plus 20 pages supplement)
openalex publication_date 2011/08/25 · arxiv created 2011/10/13 · arxiv updated 2011/10/14 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Cuprate high-temperature superconductors exhibit a pseudogap in the normal state that decreases monotonically with increasing hole doping and closes at x ≈ 0.19 holes per planar CuO 2 while the superconducting doping range is 0.05 < x < 0.27 with optimal T c at x ≈ 0.16. Using ab initio quantum calculations at the level that leads to accurate band gaps, we found that four-Cu-site plaquettes are created in the vicinity of dopants. At x ≈ 0.05, the plaquettes percolate, so that the Cu d x 2 y 2 /O p σ orbitals inside the plaquettes now form a band of states along the percolating swath. This leads to metallic conductivity and, below T c, to superconductivity. Plaquettes disconnected from the percolating swath are found to have degenerate states at the Fermi level that split and lead to the pseudogap. The pseudogap can be calculated by simply counting the spatial distribution of isolated plaquettes, leading to an excellent fit to experiment. This provides strong evidence in favor of inhomogeneous plaquettes in cuprates.