SWAP Gate for Spin Qubits Based on Silicon Devices Integrated with a Micromagnet
In our toolbox of quantum gates for spin qubits, the SWAP-family gates based on Heisenberg exchange coupling are quite versatile: the SWAP gate can help solve the connectivity problem by realizing both short- and long-range spin state transfer, while the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msqrt><mml:mrow><mml:mi>S</mml:mi><mml:mi>W</mml:mi><mml:mi>A</mml:mi><mml:mi>P</mml:mi></mml:mrow></mml:msqrt></mml:math> gate is a basic two-qubit entangling gate. Here we demonstrate a SWAP gate in a double quantum dot in isotopically enriched silicon in the presence of a micromagnet. We achieve a two-orders-of-magnitude adjustable ratio between the exchange coupling <i>J</i> and the Zeeman energy difference Δ<i>E</i><sub><i>z</i></sub>, overcoming a major obstacle for a high-fidelity SWAP gate. We also calibrate the single-qubit local phases, evaluate the logical-basis fidelity of the SWAP gate, and further analyze the dominant error sources. These results pave the way for high-fidelity SWAP gates and processes based on them, such as quantum communication on chip and quantum simulation.
Authors
- Gang Cao (ORCID: https://orcid.org/0000-0002-3599-5496)
- Wei-Zhu Liao (ORCID: https://orcid.org/0000-0003-3258-0225)
- Hong-Wen Jiang (ORCID: https://orcid.org/0000-0002-1816-6610)
- Ning Chu (ORCID: https://orcid.org/0000-0003-1514-873X)
- Zhenzhen Kong (ORCID: https://orcid.org/0000-0001-8563-5424)
- Sheng-Kai Zhu
- Hai-Ou Li (ORCID: https://orcid.org/0000-0002-9898-4735)
- Rong-Long Ma
- Guilei Wang (ORCID: https://orcid.org/0000-0002-1311-8863)
- Guo‐Ping Guo (ORCID: https://orcid.org/0000-0002-2179-9507)
- Xiao Xue (ORCID: https://orcid.org/0000-0003-1204-9883)
- Xuedong Hu (ORCID: https://orcid.org/0000-0001-7133-804X)
- Ming Ni (ORCID: https://orcid.org/0000-0003-1357-6263)
- Ao-Ran Li
- Chu Wang
Institutions
- University of Science and Technology of China (CN)
- Chinese Academy of Sciences (CN)
- University of California System (US)
- Hefei University (CN)
- Quantum (Australia) (AU)
- Institute of Microelectronics (CN)
- Kavli Energy NanoScience Institute (US)
- Origin Quantum Computing Technology Company (China) (CN)
- University at Buffalo, State University of New York (US)
- Delft University of Technology (NL)
Publication Details
- Journal
- Nano Letters
- Published
- 2025-02-28
- DOI
- https://doi.org/10.1021/acs.nanolett.4c05540
- Citations
- 2
- Primary Topic
- Quantum and electron transport phenomena
- Type
- article
- Field-Weighted Citation Impact
- 2.49
Funders
- National Natural Science Foundation of China
- Horizon 2020 Framework Programme
- Army Research Office