Dynamics of coupled two-dimensional Cu(Mn) spin-glass films

Time-dependent susceptibility measurements have been performed on multilayered two-dimensional (2D) 40-{}-wide Cu0.865{Mn}0.135$ spin-glass films, separated by Cu interlayers of width 10${w}ᵢₗ1200 . It is found that samples with{w}ᵢₗ30 display 3D dynamic behavior. For 30{w}ᵢₗ600 a gradual decoupling of the spin-glass layers occurs, and for{w}ᵢₗ${≥}600 {} typical 2D behavior is observed. The effect of a finite interlayer coupling on the dynamic susceptibility is a distinct crossover from 2D dynamic behavior at short observation times to 3D dynamic behavior at long times. A clear influence on the spin-glass dynamics is still observable for interlayer thicknesses of order 500 {}; i.e., multilayered spin-glass films are extremely sensitive probes of the effective range of Ruderman-Kittel-Kasuya-Yosida interaction mediated via metallic interlayers. The results also yield information on the relation between time scale and length scale in relaxation experiments, a fundamental concept of domain theories of the spin-glass phase.