Spin Entanglement of Three qubit GHZ and W states in Gravitational field

IICQI 2012

Entanglement degradation caused by gravitational field is studied for a system of three massive spin 1/2 particles described by a wave packet with Gaussian momentum distribution and a spin part in the form of GHZ or W states. The fidelity for particles moving around the Schwarzschild spacetime. Both the acceleration of the system and the curvature of the spacetime cause to produce a wigner rotation acting on the wave packet as it moves along a path in the curved spacetme. For considered circular paths, the spin fidelity of initial and final state is obtained as a function of angular velocity , elapsed proper time and radius of circular paths. Using a numerical approach, the behavior of the spin fidelity in terms of the sngular velocity, as well as the radius of paths is described for both GHZ and W states.