February 2024 | Jialun Li, Zhihao Xie, Yachen Li, Yansen Liang, Zhenhua Li, and Tao Li
This article presents a heralded protocol for generating distributed entanglement between two nonlocal error-protected logical qubits, which is essential for fault-tolerant distributed quantum computing. The protocol uses a high-dimensional single photon to evolve physical qubits into a logical qubit that entangles with the photon. The logical qubit-photon entanglement is then converted into entanglement between two logical qubits when the photon state is properly tuned and an effective photon-spin interface is exploited. The success of the entanglement generation is heralded by the detection of the photon, and the corresponding efficiency can, in principle, approach unity. These features make the protocol highly appealing for future large-scale quantum technologies.
Quantum error correction is essential for achieving reliable quantum information processing tasks, as it can mitigate the detrimental effects of noise by encoding single-qubit information into a larger quantum system. However, the generation of distributed entanglement between logical qubits located within two spatially separated nodes presents a significant resource-intensive challenge. The protocol proposed here is distinct from existing ones because it directly prepares photon-logical-qubit entanglement and then converts it into entanglement between two spatially separated logical qubits. The protocol shows a significant reduction in the number of quantum entangling gates needed to map the logical qubit state onto the physical qubits. Furthermore, the heralded property of the protocol has the potential to create a significant improvement in the scalability of quantum networks by reducing the possibility of error accumulation and simplifying the error correction process. These properties and advantages make the protocol highly appealing for realizing future fault-tolerant quantum networks and distributed quantum computing.This article presents a heralded protocol for generating distributed entanglement between two nonlocal error-protected logical qubits, which is essential for fault-tolerant distributed quantum computing. The protocol uses a high-dimensional single photon to evolve physical qubits into a logical qubit that entangles with the photon. The logical qubit-photon entanglement is then converted into entanglement between two logical qubits when the photon state is properly tuned and an effective photon-spin interface is exploited. The success of the entanglement generation is heralded by the detection of the photon, and the corresponding efficiency can, in principle, approach unity. These features make the protocol highly appealing for future large-scale quantum technologies.
Quantum error correction is essential for achieving reliable quantum information processing tasks, as it can mitigate the detrimental effects of noise by encoding single-qubit information into a larger quantum system. However, the generation of distributed entanglement between logical qubits located within two spatially separated nodes presents a significant resource-intensive challenge. The protocol proposed here is distinct from existing ones because it directly prepares photon-logical-qubit entanglement and then converts it into entanglement between two spatially separated logical qubits. The protocol shows a significant reduction in the number of quantum entangling gates needed to map the logical qubit state onto the physical qubits. Furthermore, the heralded property of the protocol has the potential to create a significant improvement in the scalability of quantum networks by reducing the possibility of error accumulation and simplifying the error correction process. These properties and advantages make the protocol highly appealing for realizing future fault-tolerant quantum networks and distributed quantum computing.