The conventional circuit paradigm, utilizing a small set of gates to construct arbitrary quantum circuits, is hindered by significant noise. In the quantum Fourier transform, for instance, the standard gate paradigm employs two CNOT gates for the partial CPhase. In contrast, some quantum computers can directly implement such operations using their native interaction, resulting in less noisy gates. Unfortunately, coherent errors degrade the performance of these gates. In Clifford gates such as the CNOT, these errors can be addressed through randomized compiling (RC). However, RC does not apply to the non-Clifford multi-qubit native implementations described above. The present work introduces and experimentally demonstrates a technique called ‘Pseudo Twirling’ (PST) to address coherent errors. We demonstrate experimentally that integrating PST with the ‘Adaptive KIK’ quantum error mitigation method enables the simultaneous mitigation of noise and coherent errors in multi-qubit non-Clifford gates.

传统的电路范式利用一小部分门来构建任意量子电路，受到大量噪声的阻碍。例如，在量子傅里叶变换中，标准门范式对部分 CPhase 使用两个 CNOT 门。相比之下，一些量子计算机可以使用其原生交互直接实现此类操作，从而减少门的噪声。不幸的是，相干误差会降低这些门的性能。在 CNOT 等 Clifford 门中，这些错误可以通过随机编译 （RC） 来解决。但是，RC 不适用于上述非 Clifford 多量子比特本机实现。这项工作介绍并实验演示了一种称为“伪旋转”（PST） 的技术来解决相干错误。我们通过实验证明，将 PST 与“自适应 KIK”量子误差缓解方法集成可以同时缓解多量子比特非 Clifford 门中的噪声和相干误差。