  Linear magnetoresistance occurs in semiconductors as a consequence of strong
electrical disorder and is characterized by nonsaturating magnetoresistance
that is proportional to the applied magnetic field. By investigating a
disordered MnAs-GaAs composite material, it is found that the magnitude of the
linear magnetoresistance (LMR) is numerically equal to the carrier mobility
over a wide range and is independent of carrier density. This behavior is
complementary to the Hall effect that is independent of the mobility and
dependent on the carrier density. Moreover, the LMR appears to be insensitive
to the details of the disorder and points to a universal explanation of
classical LMR that can be applied to other material systems.
