Low-Temperature Relaxation in Spin Glasses

摘要: We analyze the mechanism governing long-time, low-temperature relaxation of thermoremanent magnetization (σTRM) in metallic spin glasses. Ideas quantum tunneling and “screening” local magnetic moments are employed to explain existence a hierarchy times. This results time decay which is described by anenhanced power law: $$\sigma _{TRM} = \sigma _0 \exp - A[\ln (\omega t)]^y t)^{ t)]y 1} $$ withy≧1. A crossover predicted below most parameters become temperature-independent.