Effects of collisional decoherence on multipartite entanglement: How entanglement might not be relatively common

Abstract

We consider the collision model of Ziman and study the robustness of N -qubit Greenberger-Horne-Zeilinger (GHZ), W, and linear cluster states. Our results show that N -qubit entanglement of GHZ states would be extremely fragile under collisional decoherence, and that of W states could be more robust than that of linear cluster states. We indicate that the collision model of Ziman could provide a physical mechanism for some known results in this area of investigation. More importantly, we show that it could give a clue as to how N -partite distillable entanglement would be relatively rare in our macroscopic classical world. © 2006 The American Physical Society.