Investigations of magnetically ordered phases on the femtosecond timescale have provided significant insights into the influence of charge and lattice degrees of freedom on the magnetic sub-system. However, short-range magnetic correlations occurring in the absence of long-range order, for example in spin-frustrated systems, are inaccessible to many ultrafast techniques. Here, we show how time-resolved resonant inelastic X-ray scattering (trRIXS) is capable of probing such short-ranged magnetic dynamics in a charge-transfer insulator through the detection of a Zhang–Rice singlet exciton. Utilizing trRIXS measurements at the O K-edge, and in combination with model calculations, we probe the short-range spin correlations in the frustrated spin chain material CuGeO₃ following photo-excitation, revealing a strong coupling between the local lattice and spin sub-systems.

飞秒时间尺度上的磁性有序相的研究为电荷和晶格自由度对磁性子系统的影响提供了重要的见识。但是，在许多情况下，例如在自旋受阻系统中，在没有长距离阶次的情况下发生的短距离磁相关是无法实现的。在这里，我们展示了时间分辨共振非弹性X射线散射（trRIXS）如何通过检测张-米单重态激子来探测电荷转移绝缘子中的这种短距离磁动力学。利用在O K边缘的trRIXS测量，并结合模型计算，我们探究了受挫自旋链材料CuGeO ₃中的短程自旋相关性 光激发后，揭示了局部晶格和自旋子系统之间的强耦合。