dc conductivity of strong and weak electron spin-orbit scattering materials near the metal-insulator transition

Abstract

A detailed comparison of two disordered alloys, ${\mathrm{Ge}}_{\mathrm{x}}$ ${\mathrm{Au}}_{1\mathrm{-}\mathrm{x}}$ and ${\mathrm{B}}_{\mathrm{x}}$ ${\mathrm{Cu}}_{1\mathrm{-}\mathrm{x}}$, is carried out near their metal-insulator transition in zero magnetic field. ${\mathrm{Ge}}_{\mathrm{x}}$ ${\mathrm{Au}}_{1\mathrm{-}\mathrm{x}}$, a high-Z material, has been shown to exhibit strong spin-orbit effects in a magnetic field, while ${\mathrm{B}}_{\mathrm{x}}$ ${\mathrm{Cu}}_{1\mathrm{-}\mathrm{x}}$, a low-Z material, has been shown to exhibit weak spin-orbit effects. Both materials have similar temperature-dependent dc conductivity behavior in zero field and approximately linear mobility edges.