Dyakonov-Perel spin relaxation near the metal-insulator transition and in hopping transport

In a heavily doped semiconductor with weak spin-orbital interaction the Dyakonov-Perel spin relaxation rate is known to be proportional to the Drude conductivity. We argue that in the case of weak spin-orbital interaction this proportionality goes beyond the Drude mechanism: At low temperatures it stays valid through the metal-insulator transition and in the range of exponentially small hopping conductivity.