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arXiv · 2010.10316

Quantum tomography of an entangled three-spin state in silicon

Kenta Takeda·Akito Noiri·Takashi Nakajima·Jun Yoneda·Takashi Kobayashi·Seigo Tarucha
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Abstract

Quantum entanglement is a fundamental property of coherent quantum states and an essential resource for quantum computing. While two-qubit entanglement has been demonstrated for spins in silicon, creation of multipartite entanglement, a first step toward implementing quantum error correction, has remained challenging due to the difficulties in controlling a multi-qubit array, such as device disorder, magnetic and electrical noises and exacting exchange controls. Here, we show operation of a fully functional three-qubit array in silicon and generation of a three-qubit Greenberger-Horne-Zeilinger (GHZ) state. We obtain a state fidelity of 88.0 percent by quantum state tomography, which witnesses a genuine GHZ-class quantum entanglement that is not biseparable. Our result shows the potential of silicon-based qubit platform for demonstrations of multiqubit quantum algorithms.

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Kenta Takeda, Akito Noiri, Takashi Nakajima, Jun Yoneda, Takashi Kobayashi, Seigo Tarucha. 2020-10-20. Quantum tomography of an entangled three-spin state in silicon. https://doi.org/10.1038/s41565-021-00925-0

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