  Effect of decoherence and correlated noise on the entanglement of X-type
state of the Dirac fields in the non-inertial frame is investigated. A two
qubit X-state is considered to be shared between the partners where Alice is in
inertial frame and Rob in an accelerated frame. The concurrence is used to
quantify the entanglement of the X-state system influenced by time correlated
amplitude damping, depolarizing and bit flip channels. It is seen that
amplitude damping and bit flip channels heavily influence the entanglement of
the system as compared to the depolarizing channel. It is found possible to
avoid entanglement sudden death (ESD) for all the channels under consideration
for {\mu}>0.75 for any type of initial state. No ESD behaviour is seen for
depolarizing channel in the presence of correlated noise for entire range of
decoherence parameter p and Rob's acceleration r. It is also seen that the
effect of environment is much stronger than that of acceleration of the
accelerated partner. Furthermore, it is investigated that correlated noise
compensates the loss of entanglement caused by the Unruh effect.

Quantum Physics