Influence of extended interactions on spin dynamics in one-dimensional cuprates

Quasi-one-dimensional (1D) materials provide a unique platform for understanding the influence of extended interactions on the physics of strongly correlated systems because of their relative structural simplicity and the existence of powerful theoretical tools well adapted to one spatial dimension. We will provide an overview of the observation of anomalous features in the single-particle spectral function in 1D cuprate chain compounds, measured by angle-resolved photoemission spectroscopy (ARPES), which were explained by the presence of a long-range attractive interaction. These interactions should leave fingerprints on other observables, notably the dynamical spin structure factor, which can be measured by neutron scattering or resonant inelastic x-ray scattering. Using time-dependent density matrix renormalization group methods, we observe a significant spectral weight redistribution in the spin structure factor across a wide range of doping starting from a simple Hubbard Hamiltonian in 1D and including long-range attractive coupling, directly through an instantaneous Coulomb interaction 𝑉 or retarded electron-phonon (el-ph) coupling. This underscores the significant impact that extended interactions can have on dynamical correlations among particles, and the importance of properly incorporating this influence in modeling. Our results demonstrate that the spin structure factor can provide a sensitive experimental constraint, complementing ARPES measurements, in identifying key interactions in 1D cuprates, beyond the standard Hubbard model.