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arXiv · 2403.06894

Multi-qubit DC gates over an inhomogeneous array of quantum dots

Jiaan Qi·Zhi-Hai Liu·Hongqi Xu
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Abstract

The prospect of large-scale quantum computation with an integrated chip of spin qubits is imminent as technology improves. This invites us to think beyond the traditional 2-qubit-gate framework and consider a naturally supported ``instruction set'' of multi-qubit gates. In this work, we systematically study such a family of multi-qubit gates implementable over an array of quantum dots by DC evolution. A useful representation of the computational Hamiltonian is proposed for a dot-array with strong spin-orbit coupling effects, distinctive $g$-factor tensors and varying interdot couplings. Adopting a perturbative treatment, we model a multi-qubit DC gate by the first-order dynamics in the qubit frame and develop a detailed formalism for decomposing the resulting gate, estimating and optimizing the coherent gate errors with appropriate local phase shifts for arbitrary array connectivity. Examples of such multi-qubit gates and their applications in quantum error correction and quantum algorithms are also explored, demonstrating their potential advantage in accelerating complex tasks and reducing overall errors.

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Jiaan Qi, Zhi-Hai Liu, Hongqi Xu. 2024-03-11. Multi-qubit DC gates over an inhomogeneous array of quantum dots. https://doi.org/10.1088/1367-2630%2Fae1635

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