Complete logic Bell-state analysis assisted with photonic Faraday rotation

Abstract

The logic Bell-state which encodes many physical qubits in a logic qubit has great application potential in the future quantum communication field, for it is robust to the decoherence in a noisy environment. In this paper, we propose a complete logic Bell-state analysis (LBSA) with the help of the auxiliary single atoms trapped in the low-quality cavity. We construct the parity-check measurement gate based on the photonic Faraday rotation effect and complete the task combined with the Hadamard operation and single-qubit measurement. The number of physical qubits encoded in each logic qubit does not affect the analysis. We also discuss the application of this LBSA in the fields of quantum teleportation and logic-qubit entanglement swapping. Our LBSA protocol may have practical application in future long-distance quantum communication.