Simulations of the quantum model for CsNiF3

Large-scale simulations are performed for a quantum model of CsNiF3, choosing the competing sets of microscopic parameters known in literature. Both quantum transfer matrix and the finite-chain diagonalization techniques are applied. High resolution data are obtained from a finite-size analysis of the simulation results and are compared with the available static measurements, revealing the best agreement for the values J/k(B) = 20.5 K and A/J = 0.425. In addition, the validity of a theoretical self-consistent harmonic approximation approach is confirmed and a zero-field specific heat experiment, crucial to resolve some remaining ambiguity, is suggested.