  The effects of the spin-orbit interaction on the tunneling magnetoresistance
of magnetic tunnel junctions are investigated. A model in which the
experimentally observed two-fold symmetry of the anisotropic tunneling
magnetoresistance (TAMR) originates from the interference between Dresselhaus
and Bychkov-Rashba spin-orbit couplings is formulated. Bias induced changes of
the Bychkov-Rashba spin-orbit coupling strength can result in an inversion of
the TAMR. The theoretical calculations are in good agreement with the TAMR
experimentally observed in epitaxial Fe/GaAs/Au tunnel junctions.
