For quantum computers to successfully solve real-world problems, it is necessary to tackle the challenge of noise: the errors that occur in elementary physical components due to unwanted or imperfect interactions. The theory of quantum fault tolerance can provide an answer in the long term, but in the coming era of noisy intermediate-scale quantum machines one must seek to mitigate errors rather than completely eliminate them. This review surveys the diverse methods that have been proposed for quantum error mitigation, assesses their in-principle efficacy, and describes the hardware demonstrations achieved to date. Commonalities and limitations among the methods are identified, while mention is made of how mitigation methods can be chosen according to the primary type of noise present, including algorithmic errors. Open problems in the field are identified, and the prospects for realizing mitigation-based devices that can deliver a quantum advantage with an impact on science and business are discussed.

中文翻译：

---

量子误差缓解

为了使量子计算机成功解决现实世界的问题，有必要解决噪声的挑战：由于不需要的或不完美的相互作用而在基本物理组件中出现的错误。从长远来看，量子容错理论可以提供一个答案，但在即将到来的嘈杂的中型量子机器时代，我们必须寻求减轻错误，而不是完全消除错误。本综述调查了为缓解量子错误而提出的各种方法，评估了其原则上的功效，并描述了迄今为止实现的硬件演示。确定了这些方法之间的共性和局限性，同时提到了如何根据存在的主要噪声类型（包括算法错误）选择缓解方法。确定了该领域的未决问题，并讨论了实现基于缓解的设备的前景，这些设备可以提供量子优势，对科学和商业产生影响。