1. Deterministic multi-qubit entanglement in a quantum network
- Author
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Zhong, Youpeng, Chang, Hung-Shen, Bienfait, Audrey, Dumur, Étienne, Chou, Ming-Han, Conner, Christopher R., Grebel, Joel, Povey, Rhys G., Yan, Haoxiong, Schuster, David I., and Cleland, Andrew N.
- Subjects
Quantum theory -- Research ,Quantum computing -- Research ,Environmental issues ,Science and technology ,Zoology and wildlife conservation - Abstract
The generation of high-fidelity distributed multi-qubit entanglement is a challenging task for large-scale quantum communication and computational networks.sup.1-4. The deterministic entanglement of two remote qubits has recently been demonstrated with both photons.sup.5-10 and phonons.sup.11. However, the deterministic generation and transmission of multi-qubit entanglement has not been demonstrated, primarily owing to limited state-transfer fidelities. Here we report a quantum network comprising two superconducting quantum nodes connected by a one-metre-long superconducting coaxial cable, where each node includes three interconnected qubits. By directly connecting the cable to one qubit in each node, we transfer quantum states between the nodes with a process fidelity of 0.911 [plus or minus] 0.008. We also prepare a three-qubit Greenberger-Horne-Zeilinger (GHZ) state.sup.12-14 in one node and deterministically transfer this state to the other node, with a transferred-state fidelity of 0.656 [plus or minus] 0.014. We further use this system to deterministically generate a globally distributed two-node, six-qubit GHZ state with a state fidelity of 0.722 [plus or minus] 0.021. The GHZ state fidelities are clearly above the threshold of 1/2 for genuine multipartite entanglement.sup.15, showing that this architecture can be used to coherently link together multiple superconducting quantum processors, providing a modular approach for building large-scale quantum computers.sup.16,17. High-fidelity deterministic quantum state transfer and multi-qubit entanglement are demonstrated in a quantum network comprising two superconducting quantum nodes one metre apart, with each node including three interconnected qubits., Author(s): Youpeng Zhong [sup.1] [sup.4] , Hung-Shen Chang [sup.1] , Audrey Bienfait [sup.1] [sup.5] , Étienne Dumur [sup.1] [sup.2] [sup.6] , Ming-Han Chou [sup.1] [sup.3] , Christopher R. Conner [sup.1] [...]
- Published
- 2021
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