Berlin 2008 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe

TT: Fachverband Tiefe Temperaturen

TT 13: Correlated Electrons: Low-dimensional Systems - Materials 1

TT 13.1: Vortrag

Dienstag, 26. Februar 2008, 09:30–09:45, H 2053

Resonant inelastic soft x-ray scattering on the spin-ladder/spin-chain system Sr₁₄Cu₂₄O₄₁ — •Justina Schlappa¹, T. Schmitt¹, A. Bendounan¹, X. Wang², A. Piazzalunga³, V. Strocov¹, B. Delley¹, B. Thielemann^1,4, H. Ronnow², G. Ghiringhelli³, M. Grioni³, L. Braicovich³, C. Dallera³, J. Mesot^1,4, and L. Patthey¹ — ¹Paul Scherrer Institut, Switzerland — ²Ecole Polytechnique Fédérale Lausanne, Switzerland — ³Politecnico di Milano, Italy — ⁴ETH Zürich, Switzerland

The layered system (Sr,Ca)₁₄Cu₂₄O₄₁, is a low-dimensional cuprate system that has been studied recently with large interest [1]. It is mixed-valent and built up of two different cupper-oxygen layers: 1-dim CuO₂ chains and quasi 1-dim Cu₂O₃ 2-leg ladders. When cooling below 200 K a full range of interresting phenomena is observed, as structural changes, formation of charge order and formation of AF-dimers on the chains.

We investigated the electronic structure of Sr₁₄Cu₂₄O₄₁ by inelastic x-ray scattering (RIXS) [2] at the Cu M_2,3 edge (3p → 3d transition). The spectra show well-pronounced inelastic signal in the constant energy loss of 1.5-2.5 eV, which originates from crystal field excitations. Differences between the different crystallographic directions and between the high- and low-temperature phase are revealed.

[1] T. Vuletic et al., Physics Reports 428, 169 (2006).

[2] A. Kotani and S. Shin, Rev. Mod. Phys. 73, 203 (2001).