Anderson localization in copper benzoate at low temperatures?

Anderson localization is a general phenomenon of wave physics, which was originally proposed for electrons in a crystal, but later was also observed for light, microwaves, ultrasound, and ultracold atoms. Actually, in a crystal, besides electrons there may exist other quasiparticles such as magnons and spinons. However the search for Anderson localization of these magnetic excitations is rare so far. Recently, spinon was shown by neutron scattering specific heat measurements, it is remarkable that the spinon thermal conductivity κs only manifests a linear temperature dependence down to 300 mK. Below 300 mK, κs/T decreases rapidly and vanishes at about 100 mK. This could be an evidence of Anderson localization. We propose to perform muon spin relaxation (MuSR) experiments to check this issue, since MuSR has the advantage that it is spin sensitive.