Uncovering and Circumventing Noise in Quantum Algorithms via Metastability

Abstract

The presence of noise is the primary challenge in realizing fault-tolerant quantum computers. In this work, we introduce and experimentally validate a novel strategy to circumvent noise by exploiting the phenomenon of metastability, where a dynamical system exhibits long-lived intermediate states. We demonstrate that if quantum hardware noise exhibits metastability, both digital and analog algorithms can be designed in a noise-aware fashion to achieve intrinsic resilience. We develop a general theoretical framework and introduce an efficiently computable noise resilience metric that avoids the need for full classical simulation of the quantum algorithm. We illustrate the use of our framework with applications to variational quantum algorithms and analog adiabatic state preparation. Crucially, we provide experimental evidence supporting the presence of metastable noise in gate-model quantum processors as well as quantum annealing devices. Thus, we establish that the intrinsic nature of noise in near-term quantum hardware can be leveraged to inform practical implementation strategies, enabling the preparation of final noisy states that more closely approximate the ideal ones.