Abstract
Temperature dependencies of gap energies and magnon lifetimes are measured in the quasi-onedimensional S = 1/2 gapped quantum magnets CH32CHNH3CuCL3 (IPA-CuCl3, where IPA denotes isopropyl ammonium) and Cu2Cl4 D8C4SO2 (Sul-Cu2Cl4) using inelastic neutron scattering. The results are compared to those found in literature for S = 1 Haldane spin chain materials and to theoretical
calculations for the O3- and ON- quantum nonlinear-models. It is found that when the T = 0 energy gap is used as the temperature scale, all experimental and theoretical curves are identical to within system-dependent but temperature-independent scaling factors of the order of unity. This quasiuniversality extends over a surprising broad T range, at least up to kT ~ 1.5.
