一句话：提出脉冲与调度协同优化框架，可扩展地抑制超导量子比特 ZZ 串扰，无需特殊硬件。
噪声是量子计算的主要障碍，ZZ 串扰是超导量子比特中最具破坏性的噪声之一。既有方法依赖特殊芯片设计，或使用脉冲优化但时间和内存随比特数指数增长，难以扩展。本文提出脉冲与调度协同优化：先优化脉冲，使单个门附近具备抑制 ZZ 串扰的能力，再设计调度策略将这一能力扩展到整个电路。该方法不依赖特殊硬件，并实现为兼容不同脉冲优化方法的通用框架。作者通过仿真和真实量子计算机进行评估：仿真中 4~12 比特保真度最高提升 81 倍（平均 11 倍），真实机器上的 Ramsey 实验也表明可大幅消除 ZZ 串扰影响。
Noise is a significant obstacle to quantum computing, and ZZ crosstalk is one of the most destructive types of noise affecting superconducting qubits. Previous approaches to suppressing ZZ crosstalk have mainly relied on specific chip design that can complicate chip fabrication and aggravate decoherence. To some extent, special chip design can be avoided by relying on pulse optimization to suppress ZZ crosstalk. However, existing approaches are non-scalable, as their required time and memory grow exponentially with the number of qubits involved. To address the above problems, we propose a scalable approach by co-optimizing pulses and scheduling. We optimize pulses to offer an ability to suppress ZZ crosstalk surrounding a gate, and then design scheduling strategies to exploit this ability and achieve suppression across the whole circuit. A main advantage of such co-optimization is that it does not require special hardware support. Besides, we implement our approach as a general framework that is compatible with different pulse optimization methods. We have conducted extensive evaluations by simulation and on a real quantum computer. Simulation results show that our proposal can improve the fidelity of quantum computing on 4∼12 qubits by up to 81× (11× on average). Ramsey experiments on a real quantum computer also demonstrate that our method can eliminate the effect of ZZ crosstalk to a great extent.
DOI 原文 · arXiv · PDF（开放获取） · DBLP
@inproceedings{XieZZAZZ22,
title = {Suppressing ZZ crosstalk of Quantum computers through pulse and scheduling co-optimization},
author = {Lei Xie and Jidong Zhai and ZhenXing Zhang and Jonathan Allcock and Shengyu Zhang and Yi-Cong Zheng},
booktitle = {ASPLOS},
year = {2022},
doi = {10.1145/3503222.3507761}
}