High-Energy Resolution Inelastic Neutron Scattering Experiment on Magnetic Fracton Dispersion in Near-Percolating Three-Dimensional Heisenberg Antiferromagnet, RbMn_0.4Mg_0.6F₃

抄録

Magnetic fractons in the near-percolating three-dimensional (3D) Heisenberg antiferromagnet, RbMn_0.4Mg_0.6F₃, were studied using inelastic neutron scattering with a high energy resolution (ΔE=17.5 μeV) and at low temperature (T=1.5 K). It was demonstrated that the fractons follow the dispersion relation of q^z (q being the wave number). The observed exponent, z=2.5, was in good agreement with the fractal dimension of the 3D system (D_f=2.48), as predicted by theory.