2020/11/13 by A. Kandala, K. X. Wei, S. Srinivasan +6 · 1 citation
Physics and Astronomy · #quant-ph
paper · pdf · doi:10.1103/physrevlett.127.130501
published as Phys. Rev. Lett. 127, 130501 (2021) · 5 pages, 3 figures plus supplement (4 pages, 3 figures)
arxiv created 2020/11/13 · arxiv updated 2021/09/29
Improving two-qubit gate performance and suppressing crosstalk are major, but often competing, challenges to achieving scalable quantum computation. In particular, increasing the coupling to realize faster gates has been intrinsically linked to enhanced crosstalk due to unwanted two-qubit terms in the Hamiltonian. Here, we demonstrate a novel coupling architecture for transmon qubits that circumvents the standard relationship between desired and undesired interaction rates. Using two fixed frequency coupling elements to tune the dressed level spacings, we demonstrate an intrinsic suppression of the static ZZ, while maintaining large effective coupling rates. Our architecture reveals no observable degradation of qubit coherence (T1,T2 > 100~μs) and, over a factor of 6 improvement in the ratio of desired to undesired coupling. Using the cross-resonance interaction we demonstrate a 180~ns single-pulse CNOT gate, and measure a CNOT fidelity of 99.77(2)% from interleaved randomized benchmarking.