Self-consistent theory of cusps in the susceptibility of spin glasses

We show that the self-consistent mean-random-molecular-field method gives a spin-glass transition at temperature $T_c$. The magnetic susceptibility is proportional to $T^{-1\mathrm{}}$ for $T>\mathrm{}{T}_c$ and exhibits a cusp at $T=T_c$, where $T_c\propto c^{\alpha }$, where $0.5<\mathrm{}\alpha <0.66\mathrm{}$. The slope of the susceptibility near the cusp is found to be a simple function of the moments of the probability distribution of internal fields at zero temperature.