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arXiv · 2006.11860

High-fidelity, high-scalability two-qubit gate scheme for superconducting qubits

Yuan Xu·Ji Chu·Jiahao Yuan·Jiawei Qiu·Yuxuan Zhou·Libo Zhang·Xinsheng Tan·Yang Yu·Song Liu·Jian Li·Fei Yan·Dapeng Yu
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Abstract

High-quality two-qubit gate operations are crucial for scalable quantum information processing. Often, the gate fidelity is compromised when the system becomes more integrated. Therefore, a low-error-rate, easy-to-scale two-qubit gate scheme is highly desirable. Here, we experimentally demonstrate a new two-qubit gate scheme that exploits fixed-frequency qubits and a tunable coupler in a superconducting quantum circuit. The scheme requires less control lines, reduces crosstalk effect, simplifies calibration procedures, yet produces a controlled-Z gate in 30ns with a high fidelity of 99.5%, derived from the interleaved randomized benchmarking method. Error analysis shows that gate errors are mostly coherence limited. Our demonstration paves the way for large-scale implementation of high-fidelity quantum operations.

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Yuan Xu, Ji Chu, Jiahao Yuan, Jiawei Qiu, Yuxuan Zhou, Libo Zhang, Xinsheng Tan, Yang Yu, Song Liu, Jian Li, Fei Yan, Dapeng Yu. 2020-06-21. High-fidelity, high-scalability two-qubit gate scheme for superconducting qubits. https://doi.org/10.1103/physrevlett.125.240503

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