The Critical Exponent $\theta'$ in Spin Glasses

Short-time dynamic scaling behavior of the 3D $\pm J$ Ising spin glass is studied by Monte Carlo methods. Starting the replicas with independent initial configurations with a small pseudo magnetization, the dynamic evolution of the overlap q(t) between two replicas is measured. The initial increase of the overlap q(t) is observed and the corresponding exponent $\theta'$ is obtained. From the scaling relation $\lambda =d/z-\theta'$, the dynamic exponent z is estimated.