  We make use of the tools of quantum information theory to shed light on the
Unruh effect. A modal qubit appears as if subjected to quantum noise that
degrades quantum information, as observed in the accelerated reference frame.
The Unruh effect experienced by a mode of a free Dirac field, as seen by a
relativistically accelerated observer, is treated as a noise channel, which we
term the Unruh channel. We characterize this channel by providing its
operator-sum representation, and study various facets of quantum correlations,
such as, Bell inequality violations, entanglement, teleportation and
measurement-induced decoherence under the effect. We compare and contrast this
channel from conventional noise due to environmental decoherence. We show that
the Unruh effect produces an amplitude-damping-like channel, associated with
zero temperature, even though the Unruh effect is associated with a non-zero
temperature. Asymptotically, the Bloch sphere subjected to the channel does not
converge to a point, as would be expected by fluctuation-dissipation arguments,
but contracts by a finite factor. We construct for the Unruh effect the inverse
channel, a non-completely-positive map, that formally reverses the effect, and
offer some physical interpretation.
