Protecting Entanglement via Quantum Error Correction

Entanglement lies at the heart of quantum information science because it represents the most essential resource for quantum communication, quantum computing, quantum sensing, etc. However, this correlation between separated subsystems is fragile due to the decoherence of each subsystem, which creates the obstacle to entanglement-assisted or entanglement-enhanced quantum information processing in practice. Therefore, protecting entanglement is essential for future quantum applications. In this talk, we will introduce our recent experimental efforts on the protection of entanglement via quantum error correction (QEC). We first demonstrate the entanglement protection between two logical qubits based on separated bosonic modes by repetitively implementing QEC on each logical qubit. Then, inspired by previous experiments of entanglement purification, we also purify the entanglement through error detecting and post-selecting trajectories of logical qubits with no error. Thus, better entanglement of logical qubits has been realized by such error detection and post-selection.