  We investigate the entanglement dynamics of two uniformly accelerated atoms
with the same acceleration perpendicular to their separation. The two-atom
system is treated as an open system coupled with fluctuating electromagnetic
fields in the Minkowski vacuum, and in the Born-Markov approximation the master
equation that describes the completely positive time evolution of the two-atom
system is derived. In particular, we investigate the phenomena of entanglement
degradation, generation, revival and enhancement. As opposed to the
scalar-field case, the entanglement dynamics is crucially dependent on the
polarization directions of the atoms. For the two-atom system with certain
acceleration and separation, the polarization directions of the atoms may
determine whether entanglement generation, revival or enhancement happens,
while for entanglement degradation, they affect the decay rate of entanglement.
A comparison between the entanglement evolution of accelerated atoms and that
of static ones immersed in a thermal bath at the Unruh temperature shows that
they are the same only when the acceleration is extremely small.
