Particle-hole asymmetry in the dynamical spin and charge responses of corner-shared 1D cuprates

It has been debated for a long time whether the single-band Hubbard can describe the low-energy physics of the cuprate or not. This talk will present the results of the multi-orbital pd-model and the single-band Hubbard model for the corner-shared 1D cuprates. Here, we focus on the doping-dependent dynamical spin and charge structure factors, which can be measured in relevant experiments. We find many interesting results that cannot be captured by the single-band Hubbard model. For example, we find that the weight of the collective spin excitations between Cu and O orbitals is comparable to the weight of the spin excitations between two Cu orbitals. Importantly, we find a particle-hole asymmetry in the orbital-resolved charge excitations, which cannot be described by the single-band Hubbard model and is relevant to resonant inelastic X-ray scattering experiments. Our results imply that the explicit inclusion of the oxygen degrees of freedom may be required to understand experimental observations.