Large enhancement of the giant magnetoresistance in inhomogeneous semiconductors: Dependence on magnetic field direction

Abstract

In high-mobility Hg1-xCdxTe (x = 0.10), the physical giant magnetoresistance (GMR), due to the orbital motion of the carriers in the applied magnetic field, is apparent at high magnetic field (H > 1/μe). At low field (H<1/μe), this is enhanced by a geometrical GMR associated with conducting inhomogeneities in the semiconductor. In previous work, we have presented a model which accounts quantitatively for the GMR enhancement. Here we report on the dependence of the GMR on the direction of the magnetic field. The transverse GMR shows the low-field boost expected; in the longitudinal case both the physical and the geometrical MR are expected to vanish, and indeed the measured longitudinal GMR is very small. © 1999 American Institute of Physics.