Magnetic excitations in stripe-ordered La1.875Ba0.125CuO4 studied using resonant inelastic x-ray scattering

The charge and spin correlations in La1.875Ba0.125CuO4 (LBCO 1/8) are studied using Cu L3 edge resonant inelastic x-ray scattering (RIXS). The static charge order (CO) is observed at a wave vector of (0.24,0) and its charge nature confirmed by measuring the dependence of this peak on the incident x-ray polarization. The damped spin excitation or "paramagnon" in LBCO 1/8 is then measured as it disperses through the CO wave vector. Within the experimental uncertainty no changes are observed in the paramagnon at that wave vector and the paramagnon seems to be similar to that measured in other cuprates, which have no static CO. Given that the stripe correlation modulates both the charge and spin degrees of freedom, it is likely that subtle changes do occur in the paramagnon due to CO. Consequently, we propose that future RIXS measurements, realized with higher-energy resolution and sensitivity, should be performed to test for these effects.