Strongly momentum-dependent screening dynamics in La0.5Sr1.5MnO4 observed with resonant inelastic x-ray scattering.

We report strongly momentum-dependent short-ranged charge screening dynamics in CE-type charge, orbital, and spin ordered La0.5Sr1.5MnO4, based on Mn K-edge resonant inelastic x-ray scattering data. Through a comparison with theoretical calculations, we show that the observed momentum dependence reflects highly localized, nearest-neighbor screening of the transient local charge perturbation in this compound with an excitonlike screening cloud, rather than delocalized screening. The size of the screening cloud is estimated to be about 0.4-0.5 interatomic distances. [ABSTRACT FROM AUTHOR]