SPIN-ORBIT CONTRIBUTION TO THE HALL-COEFFICIENT APPROACHING THE METAL-INSULATOR-TRANSITION - AN EXPLANATION FOR THE CRITICAL-BEHAVIOR OF GE-SB

It is demonstrated that the band spin-orbit contribution to the Hall conductivity yx can qualitatively explain the critical behavior of the Hall coefficient RH for Ge:Sb reported by Field and Rosenbaum. The spin-orbit contribution to yx for n-type Ge has been experimentally determined by Chazalviel and leads to an RH-1 versus (n/nc-1) dependence that is consistent with the Ge:Sb data. This result demonstrates a significant extraordinary contribution to RH for some very weakly paramagnetic metal-insulator systems when closely approaching the critical density nc. © 1990 The American Physical Society.