2009/09/28 by Y. Matiks, Peter Horsch, P. Horsch +4
Materials Science · Physics and Astronomy · #Condensed matter physics #Copper-based nanomaterials and applications #Coulomb #Electron #Exciton #Hubbard model #Materials science #Mott insulator #Physics #Physics of Superconductivity and Magnetism #Quantum mechanics #Superconductivity #ZnO doping and properties #cond-mat.other #cond-mat.str-el
paper · pdf · doi:10.1103/physrevlett.103.187401
published as Phys. Rev. Lett. 103, 187401 (2009) -- Published October 27, 2009 · 4 pages with 4 figures and EPAPS supplementary online material (3 pages with 4 figures), accepted in Phys. Rev. Lett
arxiv created 2009/09/28 · openalex publication_date 2009/10/27 · arxiv updated 2015/05/14 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Spectroscopic ellipsometry was used to study the dielectric function of LiCuVO4, a compound comprised of chains of edge-sharing CuO4 plaquettes, in the spectral range 0.75-6.5 eV at temperatures 7-300 K. For photon polarization along the chains, the data reveal a weak but well-resolved two-peak structure centered at 2.15 and 2.95 eV whose spectral weight is strongly enhanced upon cooling near the magnetic ordering temperature. We identify these features as an exciton doublet in the Mott-Hubbard gap that emerges as a consequence of the Coulomb interaction between electrons on nearest and next-nearest-neighbor sites along the chains. Our results and methodology can be used to address the role of the long-range Coulomb repulsion for compounds with doped copper-oxide chains and planes.