SCALING OF THE CONDUCTIVITY OF SI-B - ANOMALOUS CROSSOVER IN A MAGNETIC-FIELD

The zero-temperature conductivity of Si:B with dopant concentrations n ear the metal-insulator transition exhibits scaling as a function of m agnetic field with an anomalously large crossover exponent. The large value of delta is associated with unusual behavior of the magnetocondu ctance, which vanishes as a power law approaching the transition. This demonstrates that Si:B, which has an anomalous critical conductivity exponent in zero field, also exhibits unusual behavior in response to a magnetic field.