Near-term quantum systems tend to be noisy. Crosstalk noise has been recognized as one of several major types of noises in superconducting Noisy Intermediate-Scale Quantum (NISQ) devices. Crosstalk arises from the concurrent execution of two-qubit gates on nearby qubits, such as \texttt{CX}. It might significantly raise the error rate of gates in comparison to running them individually. Crosstalk can be mitigated through scheduling or hardware machine tuning. Prior scientific studies, however, manage crosstalk at a really late phase in the compilation process, usually after hardware mapping is done. It may miss great opportunities of optimizing algorithm logic, routing, and crosstalk at the same time. In this paper, we push the envelope by considering all these factors simultaneously at the very early compilation stage. We propose a crosstalk-aware quantum program compilation framework called CQC that can enhance crosstalk mitigation while achieving satisfactory circuit depth. Moreover, we identify opportunities for translation from intermediate representation to the circuit for application-specific crosstalk mitigation, for instance, the \texttt{CX} ladder construction in variational quantum eigensolvers (VQE). Evaluations through simulation and on real IBM-Q devices show that our framework can significantly reduce the error rate by up to 6$\times$, with only $\sim$60\% circuit depth compared to state-of-the-art gate scheduling approaches. In particular, for VQE, we demonstrate 49\% circuit depth reduction with 9.6\% fidelity improvement over prior art on the H4 molecule using IBMQ Guadalupe. Our CQC framework will be released on GitHub.
翻译:近距离量子系统往往比较吵闹。 交叉听觉噪音被公认为超导中度量子( NISQ) 设备中若干主要类型的噪音之一。 交叉听觉来自同时在附近qubit( 如\ textt{ CX} ) 上同时执行两Q门。 它可能会大大提高门门的误差率, 而不是单独运行门的误差率。 交叉听觉可以通过时间安排或硬件机调控来减轻。 但是, 以前的科学研究, 通常在硬件绘图完成后, 在汇编过程中一个非常晚的阶段管理交叉听觉。 它可能会错过优化算法深度逻辑、 路程和交叉听觉的巨大机会。 在本文中, 我们同时在非常早期的编译阶段同时考虑所有这些因素。 我们提议一个交叉听觉的量程序汇编框架叫做CQC, 它可以在达到令人满意的电路深度的同时加强交叉听觉的缓解。 此外, 我们只能找到从中间代表到应用特定时间流流流流流流的转换机会, 例如, 在硬件 Q Q Q 将比 水平结构结构 降低 我们的校程的变压框架 。