The past, present and future of error mitigation

Decoherence and gate errors lead to faulty quantum computation. While quantum error correction is widely regarded as the only known path to realizing the full potential of quantum computing, it has yet to be implemented at scale on current hardware platforms. This raises a central question: What can one achieve with existing, noisy quantum processors before the advent of fault tolerance? I will discuss how this question motivated the development and implementation of error mitigation techniques to perform reliable quantum computation on current processors. I will present the historical development of these experiments, the current state and impact of these techniques, and their relevance as devices advance toward the fault-tolerant era.