Improving quantum gate fidelities by using a qubit to measure microwave pulse distortions.
Improving quantum gate fidelities by using a qubit to measure microwave pulse distortions.
复制标题
DOI：
10.1103/physrevlett.110.040502
复制
发表时间：
2012-11
影响因子：
8.6
通讯作者：
S. Gustavsson;O. Zwier;J. Bylander;F. Yan;F. Yoshihara;Yasunobu Nakamura;T. Orlando;W. Oliver
中科院分区：
文献类型：
--
作者：
S. Gustavsson;O. Zwier;J. Bylander;F. Yan;F. Yoshihara;Yasunobu Nakamura;T. Orlando;W. Oliver
我们提出了一种确定脉冲缺陷和提高超导量子比特单门保真度的新方法。通过施加连续的正负π脉冲，我们放大了由于微波脉冲畸变引起的量子比特演化，这导致量子比特状态围绕垂直于预期旋转轴的轴旋转。测量这些旋转作为脉冲周期的函数使我们能够重建到达样品的微波脉冲的形状。使用提取的响应来预扭曲输入信号，我们能够将每个门的平均误差降低37%，这使我们能够达到高于0.998的平均单量子比特门保真度。
We present a new method for determining pulse imperfections and improving the single-gate fidelity in a superconducting qubit. By applying consecutive positive and negative π pulses, we amplify the qubit evolution due to microwave pulse distortions, which causes the qubit state to rotate around an axis perpendicular to the intended rotation axis. Measuring these rotations as a function of pulse period allows us to reconstruct the shape of the microwave pulse arriving at the sample. Using the extracted response to predistort the input signal, we are able to reduce the average error per gate by 37%, which enables us to reach an average single-qubit gate fidelity higher than 0.998.