Fundamentale Korrelationen zwischen magnetischer Ordnung und itineranten Ladungsträgern in stark korrelierten Übergangsmetall-Oxiden

• Applicant: Professor Dr. Robert Kaindl
• Subject Area: Experimental Condensed Matter Physics
• Term: from 2000 to 2003
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 5264046

We propose femtosecond experiments to study ultrafast carrierspin interactions in strongly correlated transition-metaloxides, including high-temperature (high-Tc) cuprate superconductors. Recent non-time-resolved neutron scattering experiments provide evidence for spatial and temporal fluctuations of charge and antiferromagnetic spin order, the influence of which on the high-Tc pairing mechanism is currently debated. Ultrafast optical spectroscopy has previously proven the potential to discern substantial ingredients of complex many-body systems (e.g. in semiconductors) by their characteristic temporal signature, undistinguishable in linear spectroscopy. The optical experiments on Cr2O3, La2-xSrxCuO4 and YBa2Cu3O7-d proposed here are designed to study in real-time, with ~ 100 fs time resolution, the evolution and mutual correlations of antiferromagnetic spin waves (magnons) and the influence of doped charge carriers on their dynamics. Our proposed experiments will employ pump-probe and four-wave mixing techniques and extend time-resolved magnetic second-harmonic spectroscopy for the first time to the study of antiferromagnetic materials.

• DFG Programme: Research Fellowships
• International Connection: USA