Benchmarking Gate Fidelities in a Si/SiGe Two-Qubit Device
Benchmarking Gate Fidelities in a Si/SiGe Two-Qubit Device
复制标题
DOI：
10.1103/physrevx.9.021011
复制
发表时间：
2019-04-18
影响因子：
12.5
通讯作者：
Vandersypen, L. M. K.
中科院分区：
文献类型：
--
作者：
Xue, X.;Watson, T. F.;Vandersypen, L. M. K.
我们报告了硅基自旋量子位中单量子位和双量子位门保真度的首次完整表征，包括两个量子位之间的串扰和误差相关性。为此，我们结合使用了标准随机基准测试和最近引入的称为字符随机基准测试的方法，该方法可以更可靠地估计该系统中的两个量子位保真度，此处为受控 Z 门提供 92% 的保真度估计。有趣的是，通过字符随机基准测试，可以通过研究仅在单量子位门的参考序列中交错两量子位门引起的额外衰减来获得双量子位门保真度。这项工作为进一步提高硅自旋量子位中所有相关门保真度超越容错量子计算的错误阈值奠定了基础。
We report the first complete characterization of single-qubit and two-qubit gate fidelities in silicon-based spin qubits, including cross talk and error correlations between the two qubits. To do so, we use a combination of standard randomized benchmarking and a recently introduced method called character randomized benchmarking, which allows for more reliable estimates of the two-qubit fidelity in this system, here giving a 92% fidelity estimate for the controlled-Z gate. Interestingly, with character randomized benchmarking, the two-qubit gate fidelity can be obtained by studying the additional decay induced by interleaving the two-qubit gate in a reference sequence of single-qubit gates only. This work sets the stage for further improvements in all the relevant gate fidelities in silicon spin qubits beyond the error threshold for fault-tolerant quantum computation.