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

我们提出了飞秒实验来研究强关联过渡金属氧化物中的超快载流子自旋相互作用，包括高温(高温)铜酸盐超导体。最近的非时间分辨中子散射实验提供了电荷和反铁磁自旋有序的空间和时间起伏的证据，它们对高T_c配对机制的影响目前尚有争议。超快光谱学以前已经证明，通过线性光谱学中无法区分的特征时间特征，可以识别复杂多体系统(例如半导体中)的实质性成分。设计了Cr2O3、La2-xSrxCuO4和YBa2Cu3O7-d的光学实验，实时研究了反铁磁自旋波(磁子)的演化和相互关联，以及掺杂载流子对其动力学的影响。我们提出的实验将使用泵浦-探测和四波混频技术，并首次将时间分辨磁二次谐波光谱扩展到反铁磁材料的研究。

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.