Hybrid quantum-classical algorithms in the noisy intermediate-scale quantum era and beyond
Hybrid quantum-classical algorithms in the noisy intermediate-scale quantum era and beyond
复制标题
噪声中尺度量子时代及以后的混合量子经典算法
DOI：
10.1103/physreva.106.010101
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发表时间：
2022-07-08
影响因子：
2.9
通讯作者：
Chancellor, Nicholas
中科院分区：
文献类型：
--
作者：
Callison, Adam;Chancellor, Nicholas
混合量子经典算法是当前量子计算研究的核心，特别是在考虑噪声中间尺度量子（NISQ）时代时，已经进行了许多实验演示。从这个角度来看，我们讨论了在一个非常广泛的意义上，它意味着一个算法是混合量子经典。我们首先非常直接地探索这个概念，通过建立一个基于抽象表示理论的定义，认为使算法混合的不是它是如何运行的（或者它消耗了多少经典资源），而是经典组件是否对计算的底层模型至关重要。然后，我们采取更广泛的观点，这个问题，回顾了一些混合算法，并讨论是什么使他们的混合，以及他们如何出现的历史和考虑有关的硬件。这导致了对这些算法未来的自然讨论。为了回答这个问题，我们转向经典计算中专用处理器的使用。经典的趋势不是新技术完全取代旧技术，而是增强旧技术。我们认为量子计算的演变不太可能有所不同：混合算法可能会在NISQ时代之后很久，甚至进入完全容错，量子处理器通过执行专门的任务来增强已经强大的经典处理器。
Hybrid quantum-classical algorithms are central to much of the current research in quantum computing, particularly when considering the noisy intermediate-scale quantum (NISQ) era, with a number of experimental demonstrations having already been performed. In this perspective, we discuss in a very broad sense what it means for an algorithm to be hybrid quantum-classical. We first explore this concept very directly, by building a definition based on previous work in abstraction-representation theory, arguing that what makes an algorithm hybrid is not directly how it is run (or how many classical resources it consumes), but whether classical components are crucial to an underlying model of the computation. We then take a broader view of this question, reviewing a number of hybrid algorithms and discussing what makes them hybrid, as well as the history of how they emerged and considerations related to hardware. This leads into a natural discussion of what the future holds for these algorithms. To answer this question, we turn to the use of specialized processors in classical computing. The classical trend is not for new technology to completely replace the old, but to augment it. We argue that the evolution of quantum computing is unlikely to be different: Hybrid algorithms are likely here to stay well past the NISQ era and even into full fault tolerance, with the quantum processors augmenting the already powerful classical processors which exist by performing specialized tasks.