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oai:ynu.repo.nii.ac.jp:02000121 2025-04-02T01:47:32Z 1006:1009

Deterministic Bell state measurement with a single quantum memory Kamimaki, Akira 0000-0001-5465-2352 Wakamatsu, Keidai 0009-0000-8917-2527 Mikata, Kosuke Sekiguchi, Yuhei 0000-0002-8850-4646 Kosaka, Hideo 0000-0002-3778-7236 20361199 Quantum information, Quantum optics Entanglements serve as a resource for any quantum information system and are deterministically generated or swapped by a joint measurement called complete Bell state measurement (BSM). The determinism arises from a quantum nondemolition measurement of two coupled qubits with the help of readout ancilla, which inevitably requires extra physical qubits. We here demonstrate a deterministic and complete BSM with only a nitrogen atom in a nitrogen-vacancy (NV) center in diamond as a quantum memory without relying on any carbon isotopes, which are the extra qubits, by exploiting electron‒nitrogen (14N) double qutrits at a zero magnetic field. The degenerate logical qubits within the subspace of qutrits on the electron and nitrogen spins are holonomically controlled by arbitrarily polarized microwave and radiofrequency pulses via zero-field-split states as the ancilla, thus enabling the complete BSM deterministically. Since the system works under an isotope-free and field-free environment, the demonstration paves the way to realize high-fidelity quantum repeaters for long-haul quantum networks and quantum interfaces for large-scale distributed quantum computers. journal article Springer Nature 2023-10-16 VoR application/pdf npj Quantum Information 9 20566387 https://ynu.repo.nii.ac.jp/record/2000121/files/20231016_Deterministic Bell state measurement with a single quantum.pdf http://hdl.handle.net/10131/0002000121 https://ynu.repo.nii.ac.jp/records/2000121 eng https://doi.org/10.1038/s41534-023-00771-z Creative Commons Attribution 4.0 International open access