Myths around quantum computation before full fault tolerance: What no-go theorems rule out and what they don't

TL;DR

This paper critically examines common misconceptions about near-term quantum computing, analyzing no-go theorems, error mitigation, and the transition toward fault-tolerance, emphasizing practical strategies and realistic expectations.

Contribution

It provides a nuanced evaluation of theoretical limitations and practical approaches, clarifying what is achievable with current and near-future quantum technologies.

Findings

No-go theorems limit certain quantum advantages

Error mitigation techniques have practical potential

Synergies between error mitigation and fault-tolerance are promising

Abstract

In this perspective article, we revisit and critically evaluate prevailing viewpoints on the capabilities and limitations of near-term quantum computing and its potential transition toward fully fault-tolerant quantum computing. We examine theoretical no-go results and their implications, addressing misconceptions about the practicality of quantum error mitigation techniques and variational quantum algorithms. By emphasizing the nuances of error scaling, circuit depth, and algorithmic feasibility, we highlight viable near-term applications and synergies between error mitigation and early fault-tolerant architectures. Our discussion explores strategies for addressing current challenges, such as barren plateaus in variational circuits and the integration of quantum error mitigation and quantum error correction techniques. We aim to underscore the importance of continued innovation in hardware and algorithmic design to bridge the gap between theoretical potential and practical utility, paving the way for meaningful quantum advantage in the era of late noisy intermediate scale and early fault-tolerant quantum devices.