2017/11/30 by Andrej Pustogow, Ying Li, Ievgen Voloshenko +7 · 21 citations
Materials Science · Physics and Astronomy · #Ab initio #Advanced Condensed Matter Physics #Band gap #Charge (physics) #Condensed matter physics #Coulomb #Cuprate #Density functional theory #Dipole #Doping #Electron #Hubbard model #Lattice (music) #Magnetic and transport properties of perovskites and related materials #Mott insulator #Optical conductivity #Physics #Physics of Superconductivity and Magnetism #Quantum mechanics #Strongly correlated material #Superconductivity #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.96.241114
published in Physical review. B./Physical review. B 96(24) (American Physical Society) · 5 pages, 5 figures, Supplemental Material
arxiv created 2017/11/30 · openalex publication_date 2017/12/29 · arxiv updated 2018/01/10 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Optical conductivity measurements are combined with density functional theory calculations in order to understand the electrodynamic response of the frustrated Mott insulators herbertsmithite ZnCu3(OH)6Cl2 and the closely related kagome-lattice compound Y3Cu9(OH)19Cl8. We identify these materials as charge-transfer rather than Mott-Hubbard insulators, similar to the high-Tc cuprate parent compounds. The band edge is at 3.3 and 3.6 eV, respectively, establishing the insulating nature of these compounds. Inside the gap, we observe dipole-forbidden local electronic transitions between the Cu 3d orbitals in the range 1--2 eV. With the help of ab initio calculations we demonstrate that the electrodynamic response in these systems is directly related to the role of on-site Coulomb repulsion: While charge-transfer processes have their origin on transitions between the ligand band and the Cu 3d upper Hubbard band, local d\text\ensuremath-d excitations remain rather unaffected by correlations.