Dynamical Structure Factor of the Three-Dimensional Quantum Spin Liquid Candidate NaCaNi 2 F 7

摘要: We study the dynamical structure factor of spin-1 pyrochlore material NaCaNi_{2}F_{7}, which is well described by a weakly perturbed nearest-neighbour Heisenberg Hamiltonian, Our three approaches-molecular dynamics simulations, stochastic theory, and linear spin wave theory-reproduce remarkably momentum dependence experimental inelastic neutron scattering intensity as its energy with exception lowest energies. discuss two surprising aspects their implications for quantum liquids in general: complete lack sharp quasiparticle excitations space success theory regime where it would be expected to fail several reasons.