Real-Time Manifestation of Strongly Coupled Spin and Charge Order Parameters in Stripe-Ordered La1.75Sr0.25NiO4La_{1.75}Sr_{0.25}Ni_{O4} Nickelate Crystals Using Time-Resolved Resonant X-Ray Diffraction

We investigate the order parameter dynamics of the stripe-ordered nickelate, La1.75Sr0.25NiO4, using time-resolved resonant x-ray diffraction. In spite of distinct spin and charge energy scales, the two order parameters’ amplitude dynamics are found to be linked together due to strong coupling. Additionally, the vector nature of the spin sector introduces a longer reorientation time scale which is absent in the charge sector. These findings demonstrate that the correlation linking the symmetry-broken states does not unbind during the nonequilibrium process, and the time scales are not necessarily associated with the characteristic energy scales of individual degrees of freedom