Realization of adiabatic and diabatic CZ gates in superconducting qubits coupled with a tunable coupler*
Realization of adiabatic and diabatic CZ gates in superconducting qubits coupled with a tunable coupler*
复制标题
DOI：
10.1088/1674-1056/abf03a
复制
发表时间：
2020-10
期刊：
影响因子：
--
通讯作者：
Huikai Xu;Weiyang Liu;Zhiyuan Li;Jiaxiu Han;Jingning Zhang;Kehuan Linghu;Yongchao Li;Mo Chen;Zhen Yang-;Junhua Wang;Teng Ma;G. Xue;Yirong Jin;Haifeng Yu
中科院分区：
文献类型：
--
作者：
Huikai Xu;Weiyang Liu;Zhiyuan Li;Jiaxiu Han;Jingning Zhang;Kehuan Linghu;Yongchao Li;Mo Chen;Zhen Yang-;Junhua Wang;Teng Ma;G. Xue;Yirong Jin;Haifeng Yu
高保真双量子比特门是放大超导数的基础。我们使用两个量子比特通过一个频率可调的耦合器耦合，可以调整耦合强度，并演示了CZ门使用两种不同的方案，绝热和双绝热方法。基于Clifford的随机基准（RB）方法被用来评估和优化CZ门保真度。绝热和双绝热CZ门的保真度分别为99.53（8）%和98.72（2）%。分析了退相干引起的误差，对于绝热CZ门，退相干引起的误差占总误差的92%，对于双绝热CZ门，退相干引起的误差占总误差的46%。绝热格式对运算误差具有较强的鲁棒性。但双绝热方案对纯度和操作误差比较敏感。与绝热CZ门的30 ns持续时间相比，双绝热CZ门的持续时间为19 ns，显示出比$r '_{\rm{incoherent，Clfford}}$ = 0.0197（5）更低的非相干误差$r'_{\rm{incoherent，Clfford}}$ = 0.0223（3）。
High fidelity two-qubit gates are fundamental for scaling up the superconducting number. We use two qubits coupled via a frequency-tunable coupler which can adjust the coupling strength, and demonstrate the CZ gate using two different schemes, adiabatic and di-adiabatic methods. The Clifford based Randomized Benchmarking (RB) method is used to assess and optimize the CZ gate fidelity. The fidelity of adiabatic and di-adiabatic CZ gates are 99.53(8)% and 98.72(2)%, respectively. We also analyze the errors induced by the decoherence, which are 92% of total for adiabatic CZ gate and 46% of total for di-adiabatic CZ gates. The adiabatic scheme is robust against the operation error. But the di-adiabatic scheme is sensitive to the purity and operation errors. Comparing to 30 ns duration time of adiabatic CZ gate, the duration time of di-adiabatic CZ gate is 19 ns, revealing lower incoherence error $r_{\rm{incoherent, Clfford}}$ = 0.0197(5) than $r'_{\rm{incoherent, Clfford}}$ = 0.0223(3).