  In this work, we report that the Hawking radiation effect on fermions is
fundamentally different from the case of scalar particles. Intrinsic properties
of fermions (exclusion principle and spin) affect strongly the interaction of
fermions with both Hawking radiation and metric of the spacetime. In particular
we have found the following: first, while the fermion vacuum state seen by the
Rindler observer is an entangled state in which the right and left Rindler
wedge states appear in correlated pairs as in the case of the scalar particles,
the entanglement disappears in the excited state due to the exclusion
principle; second, the spin of the fermion experiences the Winger rotation
under a uniform acceleration; and third, the quantum information of fermions
encoded in spin (entangled state is composed of different spin states but with
the same mode function) is dissipated not by the Hawking radiation but by the
Wigner rotation as the pair approaches the event horizon.
