Anomalous Behavior of Superconducting-Normal Mesoscopic Structures near $T_c$

We observe a maximum in the conductance of $\mathrm{Al}/n-\mathrm{GaAs}$ junctions at temperatures 20 mK lower than the superconducting transition temperature $\left(T_c\right)$. This is the first observation of a peak in the conductance near the superconducting transition in superconducting-normal $\left(S/N\right)$ junctions. To accommodate this effect we calculate the full temperature dependence of the conductance of these structures, invoking quasiclassical Green's functions in the diffusive limit. In addition to the well-known low-temperature peak at temperatures on the order of the Thouless energy, we find a maximum near $T_c$. This peak has the same origin as the subgap conductance observed in $S/N$ junctions at low temperatures.