  Modeling the qubit by a two-level semiclassical detector coupled to a
massless scalar field, we investigate how the Unruh effect affects the
nonlocality and entanglement of two-qubit and three-qubit states when one of
the entangled qubits is accelerated. Two distinct differences with the results
of free field model in non-inertial frames are (i) for the two-qubit state, the
CHSH inequality can not be violated for sufficiently large but finite
acceleration, furthermore, the concurrence will experience "sudden death"; and
(ii) for the three-qubit state, not only the entanglement vanishes in the
infinite acceleration limit, but also the Svetlichny inequality can not be
violated in the case of large acceleration.
