Possible Role of Incipient Anderson Localization in the Resistivities of Highly Disordered Metals

The scaling theory of Anderson localization by Abrahams et al. is used for dirty conductors just above the Anderson transition. When the inelastic mean free path, $l_{\mathrm{ph}}$, is smaller than the coherence length, $\xi$, in the extended phase, the conductivity increases with temperature like ${l_{\mathrm{ph}}}^{-1\mathrm{}}$. This may be related to the quite general correlation between large resistances and their negative temperature derivatives found by Mooij. $l_{\mathrm{ph}}>\xi$ is required to distinguish between the extended and localized regimes.