Year: 2025
Type: article
Abstract: 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 S W A P 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 J and the Zeeman energy difference Δ E z, 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.
Source: Nano Letters
Institutions: University of Science and Technology of China, CAS Key Laboratory of Quantum Information, USTC, Chinese Academy of Sciences, Institute of Microelectronics, Institute of Microelectronics, QuTech, Delft University of Technology, University at Buffalo, State University of New York, University of California System, Origin Quantum Computing Technology Company (China)
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W4408035314