论文标题
用工程ZZ抑制的固定频率传输的高保真CNOT的演示
Demonstration of a High-Fidelity CNOT for Fixed-Frequency Transmons with Engineered ZZ Suppression
论文作者
论文摘要
提高两分门的性能和抑制串扰是主要但经常竞争的挑战，这是实现可扩展量子计算的挑战。特别是，增加耦合以实现更快的大门的耦合与增强的串扰，这是由于在哈密顿量中不必要的两分项术语而与增强的串扰联系在一起。在这里，我们展示了一种新型的耦合体系结构，用于跨越量子位，该结构规避了所需的相互作用速率和不希望的相互作用速率之间的标准关系。使用两个固定的频率耦合元件来调整穿着的水平间距，我们展示了对静态$ ZZ $的内在抑制，同时保持了较大的有效耦合速率。我们的体系结构没有发现量子相干性的可观察到的降解（$ t_1，t_2> 100〜μs $），并且在所需的不希望耦合的比率上提高了6倍。使用交叉谐振相互作用，我们证明了一个180 〜ns的单脉冲CNOT门，并通过交织的随机基准测试中测量99.77（2）$ \％$的CNOT保真度。
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 ($T_1,T_2 > 100~μs$) 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.
