摘要
Applying a three-band model and the random phase approximation,we theoretically study the spin excitations in nickelate superconductors,which have been newly discovered.The spin excitations were found to be incommensurate in the low energy region.The spin resonance phenomenon emerged as the excitation energy increased.The intensity can be maximized at the incommensurate or commensurate momentum,depending on the out-of-plane momentum.The spin excitations reverted to incommensurate at higher energies.We also discuss the similarities and differences in the spin excitations of nickelate and cuprate superconductors.Our predicted results can be later validated in inelastic neutron scattering experiments.
基金
supported by the National Key Research and Development Program of China(Grant No.2016YFA0301800)
the General Research Fund(GRF)(Grant Nos.HKU 173309/16P,and HKU173057/17P)
the Collaborative Research Fund(CRF)(Grant No.C6005-17G)of Hong Kong。