Logarithmic dynamic scaling in spin-glasses

Abstract

Evidence is presented that "freezing" in spin-glasses is a consequence of anomalous critical slowing down associated with a zero-temperature transition: temperature and field dependences of the relaxation time are compatible with $\ln \tau \propto T^{-\nu z}f\left({\mathrm{HT}}^{-\Delta }\right)$ both for nearest-neighbor ±$J$-Ising models and ${\mathrm{Eu}}_{0.4}$ ${\mathrm{Sr}}_{0.6}$S. The exponents $\nu ,z$, and $\Delta$ are estimated. Also, the nonlinear susceptibility of $\mathrm{Cu}$ Mu 1% is shown to be very similar to that of the $d=3\mathrm{}$, $\pm J$ model, compatible with our description.