Kim, Kyung Wan Gu, G. D. 2009-02-24 We investigated excitation spectra of the one-dimensional chain compound Sr₂CuO₃. The small peak at 2.3 eV in the loss function turned out to correspond to the strong charge-transfer transition at 1.8 eV in conductivity. It has the excitonic character expected in one-dimensional extended Hubbard model of the transition from the lower Hubbard band to the Zhang-Rice singlet state. The strongest peak at 2.7 eV in the loss function is attributed to the continuum excitation of the excitonic charge-transfer transition. The spectral weight sum rule is satisfied within these transitions. application/pdf https://folia.unifr.ch/global/documents/301219 https://folia.unifr.ch/documents/301219/files/kim_oes.pdf eng info:eu-repo/semantics/altIdentifier/doi/10.1103/PhysRevB.79.085121 info:eu-repo/semantics/openAccess License undefined Physical Review B. - 2009, vol. 79, no. 8, p. 085121 charge transfer states excitons high-temperature superconductors Hubbard model optical conductivity reflectivity strontium compounds info:eu-repo/classification/udc/53 Optical excitations in Sr₂CuO₃ http://purl.org/coar/resource_type/c_6501