Magnetic impurity effects on the entanglement of three-qubit Heisenberg XY chain with intrinsic decoherence

We investigate a three-qubit Heisenberg XY chain with magnetic impurity in the model of Milburn's intrinsic decoherence and the pairwise entanglement is calculated by making use of the concurrence. It is shown that the nearest neighbor pairwise entanglement rapidly decay due to intrinsic decoherence, but next to nearest neighbor qubits finally stay in a entangled stationary state in the case without the magnetic impurity. The magnetic impurity in the central qubit can protect the nearest neighbor pairwise entanglement from being completely destroyed by the intrinsic decoherence.