Wigner rotation of a spin 1/2 particle near the event horizon of a Schwarzschild black hole

The effects of Wigner rotation on a particle with spin 1/2 near the event horizon of a Schwarzschild black hole are studied in the Kruskal spacetime. The curvature of spacetime is found to cause a Winger rotation on spin of the particle in the curved spacetime. This implies that, from a quantum information processing point of view, any quantum information encoded in the spin will be dissipated near the black hole. The gravitational field around the black hole, thus, acts like a dissipative quantum channel.