Giant negative magnetoresistance in semiconductors doped by multiply charged deep impurities

Abstract

A giant negative magnetoresistance has been observed in bulk germanium doped with multiply charged deep impurities. Applying a magnetic field the resistance may decrease exponentially at any orientation of the field. A drop of the resistance as much as about 10 000% has been measured at 6 T. The effect is attributed to the spin splitting of impurity ground state with a very large g factor in the order of several tens depending on impurity.