LONGITUDINAL FIELD µSR IN CuMn SPIN GLASSES BELOW Tf

We report on longitudinal field muon spin relaxation measurements in CuMn spin glasses below the freezing temperature Tf. The dynamic relaxation rate λd varies with field as λd ~ B-αwith a temperature dependent exponent α. This confirms a power law decay for the local field autocorrelation function Sd (t) ~ t-γ, but the temperature dependence of the exponent γ is not in agreement with theoretical mean field calculations