论文标题
通用采样下限以减轻量子误差
Universal Sampling Lower Bounds for Quantum Error Mitigation
论文作者
论文摘要
已经提出了许多量子误差协议，这是出于抑制对中等规模量子设备的噪声影响的迫切需要的动机。然而，它们的一般潜力和局限性仍然难以捉摸。特别是，要了解减轻量子误差的最终可行性，表征基本抽样成本至关重要 - 任意缓解协议必须运行嘈杂的量子设备多少次。在这里，我们建立了缓解量子误差的采样成本的通用下限，以高概率达到所需的准确性。我们的界限适用于一般缓解协议，包括涉及非线性后处理的协议以及尚未发现的协议。结果表明，用于减轻错误的广泛协议所需的采样成本必须在各种噪声模型的电路深度中成倍增长，从而揭示了有用的噪声近期量子设备可扩展性的基本障碍。
Numerous quantum error-mitigation protocols have been proposed, motivated by the critical need to suppress noise effects on intermediate-scale quantum devices. Yet, their general potential and limitations remain elusive. In particular, to understand the ultimate feasibility of quantum error mitigation, it is crucial to characterize the fundamental sampling cost -- how many times an arbitrary mitigation protocol must run a noisy quantum device. Here, we establish universal lower bounds on the sampling cost for quantum error mitigation to achieve the desired accuracy with high probability. Our bounds apply to general mitigation protocols, including the ones involving nonlinear postprocessing and those yet-to-be-discovered. The results imply that the sampling cost required for a wide class of protocols to mitigate errors must grow exponentially with the circuit depth for various noise models, revealing the fundamental obstacles in the scalability of useful noisy near-term quantum devices.
