Theoretical description of charge excitations in low-dimensional undoped cuprates

Abstract

We investigate Cu 2p 3/2 X-ray photoemission spectra of low-dimensional undoped cuprates within a multi-band Hubbard model, using a cumulant projection technique. This method makes the treatment of infinite systems possible while still allowing for a clear interpretation of final states. Delocalization processes and multiplet splitting are described within one framework. The results are compared to those of exact diagonalization calculations and to experimental spectra of Bi2CuO4 and Sr2CuO3. For both compounds the calculations are in good agreement with the experiment. The charge-transfer energy ∆ for Sr2CuO3 is found to be smaller than in other cuprates.

Dynamics of a hole in aCuO4plaquette: Electron energy-loss spectroscopy ofLi2Atzkern1, Knupfer2, Golden3 et al. 2000Phys. Rev. B363260View full textAdd to dashboardCite

“…As explained in Ref. 20 In Figs. 3͑b͒ and 5 the theoretical results are compared to the experimental EELS and XPS spectra.…”

Core-hole screening response in two-dimensional cuprates: A high-resolution x-ray photoemission study

“…Several theoretical approaches have been able to describe satisfactorily the spectra of zero-dimensional and one-dimensional cuprates, but have failed to describe the data from the two-dimensional cuprate Sr 2 CuO 2 Cl 2 correctly. 10,16,17 The main line of this compound is comprised of two components, whereby the leading structure is very broad. The theories, however, predict this low-energy component to be rather narrow.…”

“…The goal of this joint experimental and theoretical investigation of two-dimensional cuprates is to determine and understand the typical situation for the twodimensional cuprates, as has been successfully carried out in the zero-and one-dimensional cases. 10,12,17 The organization of the paper is as follows. In Sec.…”

Cu-O network-dependent core-hole screening in low-dimensional cuprates: A theoretical analysis

“…These results have already been described elsewhere. 26 Here, we therefore discuss only those aspects which are relevant for the influence of dimensionality and lattice geometry.…”

“…We compare our calculations with the experimental spectra of three materials which consist of different Cu-O networks: Bi In the case of zero-dimensional edge-shared or separated plaquettes (like Bi 2 CuO 4 ) the main line consists of a single feature which is explained by a local process in which the valence hole moves from the core-hole site to the surrounding O sites. 19,26 For one-dimensional zigzag or linear chains (like Sr 2 CuO 3 ) two features contribute to the main line. In the case of two-dimensional planar systems (like Sr 2 CuO 2 Cl 2 ) the main line is composed of at least three features.…”