Persistent currents in diffusive metallic cavities: Large values and anomalous scaling with disorder

The effect of disorder on confined metallic cavities with an Aharonov-Bohm flux line is addressed. We find that, even deep in the diffusive regime, large values of persistent currents may arise for a wide variety of geometries. We present numerical results supporting an anomalous scaling law of the average typical current $< I_{typ}>$ with the strength of disorder $w$, $< I_{typ}> \sim w^{- \gamma}$ with $\gamma < 2$. This is contrasted with previously reported results obtained for cylindrical samples where a scaling $< I_{typ}> \sim w^{-2}$ has been found. Possible links to, up to date, unexplained experimental data are finally discussed.