Fig. 4: Direct-space and time response functions, χ″(x, t) = − iF [χ″(Q, E)], as a function of temperature.
From: High-temperature quantum coherence of spinons in a rare-earth spin chain
A–D Calculated from inelastic neutron scattering spectra; E–H Calculated from fits to inelastic neutron data; I–L Obtained from DMRG calculations. Dashed black lines mark the edge of the light-cone in the ballistic regime, \(t=\frac{x}{2\pi v}\), while dotted green curves highlight the long-time super-diffusive behavior, t ~ x3/2 54, prominent at high temperatures.
