Universal Scaling of the Magnetoconductance of Metallic Si:B

Conductivity data for Si:B samples with dopant concentrations 1.01 nc<n<1.22nc at temperatures between 0.07 and 0.5 K in magnetic fields from 0 to 9.0 T collapse onto a single universal curve Δσ0ex0ex=0ex0exKT1/2F(H/T), the form expected for the magnetoconductance due to electron-electron interactions. This suggests that the metal-insulator transition is predominantly driven by electron correlations, and that localization, spin-flip scattering, and spin-orbit scattering are unimportant despite strong spin-orbit effects in Si:B.