Magnetic excitations of the frustrated ferromagnetic chain LiCuSbO₄

J₁ - J₂ one-dimensional frustrated spin-1/2 chains with ferromagnetic J₁ are believed to host novel states such as vector chiral orders, spin nematic states and spin density wave states. Especially the competition between spin nematic states and spin density wave states in external magnetic field has been drawing much attention. With a feasible saturation field H_sat ~ 12 T, LiCuSbO₄ serves as a good experimental candidate. Recent NMR and μSR studies have found evidence for a multipolar nematic phase at certain field range. In our work, we measured detailed ineslatic neutron scattering spectra on powder sample at low temperature in various magnetic fields. The results, along with recent theoretical studies, help us narrow down the detailed Hamiltonian and explore the possible phases in the system, in particular, in light of possible dimerization of the J₁ exchange.