Experimental evidence for magnetic two level systems in spin glasses (invited)

摘要: We report about low temperature measurements of susceptibility, magnetization, and time dependence the thermoremanent magnetization on amorphous magnetic alloys (PdCuSi) with transition metals Mn, Fe, Co in a concentration x=5 to 20 at. %. Alloys concentrations show single peak spin‐glass behavior. The more concentrated samples double transitions, an upper at Tc into ferromagnetic state, followed by lower Tg state which has spin‐ or cluster‐glass character. Evidence for this comes from onset irreversibility remanence, features are absent above Tg. results can be interpreted thermal relaxation cluster moments over anisotropy barriers, equivalent picture existence two‐level systems (MTLS). Direct evidence MTLS investigations phonon conductivity κPh(T) studied as function field. En...