Distant spin entanglement via fast and coherent electron shuttling

• Published in: Nature nanotechnology Vol. 16; no. 5; pp. 570 - 575
• Main Authors: Jadot, Baptiste, Mortemousque, Pierre-André, Chanrion, Emmanuel, Thiney, Vivien, Ludwig, Arne, Wieck, Andreas D., Urdampilleta, Matias, Bäuerle, Christopher, Meunier, Tristan
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.05.2021; Nature Publishing Group
• Subjects: 639/766/119/1000/1017; 639/766/483/2802; 639/925/927/481; Chemistry and Materials Science; Computers; Condensed Matter; Displacement; Electron spin; Materials Science; Mesoscopic Systems and Quantum Hall Effect; Nanotechnology; Nanotechnology and Microengineering; Physics; Quantum computers; Quantum computing; Quantum dots; Quantum entanglement; Qubits (quantum computing); Route selection; Semiconductors; Separation; Surface acoustic waves; Trapping
• ISSN: 1748-3387; 1748-3395
• DOI: 10.1038/s41565-021-00846-y

In the quest for large-scale quantum computing, networked quantum computers offer a natural path towards scalability. While recent experiments have demonstrated nearest neighbour entanglement for electron spin qubits in semiconductors, on-chip long-distance entanglement could bring more versatility to connect quantum core units. Here, we employ the moving trapping potential of a surface acoustic wave to realize the controlled and coherent transfer of a pair of entangled electron spins between two distant quantum dots. The subsequent electron displacement induces coherent spin rotations, which drives spin quantum interferences. We observe high-contrast interference as a signature of the preservation of the entanglement all along the displacement procedure, which includes a separation of the two spins by a distance of 6 μm. This work opens the route towards fast on-chip deterministic interconnection of remote quantum bits in semiconductor quantum circuits. On-chip, long-distance entanglement of spin qubits in semiconductors could enable connectivity of quantum core units for networked quantum computing. The moving trapping potential of a surface acoustic wave can subsequently displace two entangled spins while preserving entanglement over a separation of 6 μm.