Dresden 2009 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 6: Postersession Correlated Electrons: (General) Theory, Low-Dimensional Systems, Kondo Physics, Heavy Fermions, Quantum-Critical Phenomena

TT 6.20: Poster

Montag, 23. März 2009, 13:00–16:45, P1A

Collective two-particle excitations in cuprates and manganites: Resonant inelastic x-ray scattering and electron energy loss spectroscopy — •Jochen Geck¹, Roberto Krauss¹, Roman Schuster¹, Martin Knupfer¹, Patrick Ribeiro¹, Bernd Büchner¹, Pieter Glatzel², Javier Herrero-Martin², Joaquin Garcia-Ruiz³, Diego Casa⁴, Thomas Gog⁴, Hiroki Wadati⁵, and George A. Sawatzky⁵ — ¹IFW Dresden, Germany — ²European Synchrotron Radiation Facility, France — ³Universidad de Zaragoza, Spain — ⁴Advanced Photon Source, USA — ⁵University of British Columbia, Canada

The two-particle charge excitations of Sr₂CuO₃, which contains one-dimensional corner-sharing CuO₂-chains, were studied by Resonant Inelastic X-ray Scattering (RIXS) at the Cu K-edge. At the center of the Brillouin zone, the dependence of the various charge-transfer excitations on the incident photon energy E_i was studied in detail. The different charge transfer excitations resonate for different intermediate states, i.e., different E_i, which allows to draw conclusions about the symmetry of the created excitations. Further, the RIXS results are discussed in comparison to previous Electron Energy Loss Spectroscopy (EELS) studies. A similar approach was then used to investigate the two-particle excitations (La,Sr)₂MnO₄. Surprisingly, the excitations observed for the doped manganite materials share similar traits with the ones observed for the doped cuprates.