Universal Sampling Lower Bounds for Quantum Error Mitigation
Abstract
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.
Cite
@article{arxiv.2208.09178,
title = {Universal Sampling Lower Bounds for Quantum Error Mitigation},
author = {Ryuji Takagi and Hiroyasu Tajima and Mile Gu},
journal= {arXiv preprint arXiv:2208.09178},
year = {2023}
}
Comments
5+15 pages, 4 figures, published version; See also a related work by Tsubouchi et al., which appeared in the same arXiv posting as arXiv:2208.09385