Experimental Determination of the Critical Spin Glass Correlation Length

Measuring ThermoRemanent Magnetization (TRM) decays on a single crystal CuMn(6\(\%\)) spin glass sample, we have systematically mapped the rapid decrease of the characteristic timescale \(tw_{eff}\) near \(T_g\). Using \(tw_{eff}\) to determine the length scale of the growth of correlations during the waiting time, \(\xi_{TRM}\), (observed in both numerical studies and experiment), we observe both growth of \(\xi_{TRM}\) in the spin glass phase and then a rapid reduction very close to \(T_g\). We interpret this reduction in \(\xi_{TRM}\), for all waiting times, as being governed by the critical correlation length scale \(\xi_{crit}=a(T-T_c)^{-\nu}\).