Robustness of multiparty nonlocality to local decoherence

摘要

We investigated the robustness of multiparty nonlocality under local decoherence, acting independently and equally on each subsystems. To be specific, we considered an N-qubit GHZ state under depolarization, dephasing, or dissipation channel, and tested the nonlocality by violation of Mermin-Klyshko inequality, which is one of Bell's inequalities for multi-qubit systems. The results showed that the robustness of nonlocality increases with the number of qubits, and that the nonlocality of an N-qubit GHZ state with even N is extremely robust against dephasing.