Concepts and conditions for error suppression through randomized compiling

TL;DR

Randomized compiling transforms various error types in quantum computing into stochastic Pauli noise, reducing error accumulation, variability, and improving overall performance, as demonstrated through theoretical analysis and IBM quantum experiments.

Contribution

This paper extends randomized compiling to non-Markovian errors, providing a comprehensive analysis and experimental validation of its error mitigation capabilities.

Findings

Prevents coherent error accumulation across gate cycles

Converts errors into local stochastic Pauli noise

Reduces variability in noisy quantum devices

Abstract

Randomized compiling reduces the effects of errors on quantum computers by tailoring arbitrary Markovian errors into stochastic Pauli noise. Here we prove that randomized compiling also tailors non-Markovian errors into local stochastic Pauli noise and investigate the technique's limitations. We show through analysis and numerical results that randomized compiling alters errors in three distinct helpful ways. First, it prevents the coherent accumulation of errors (including hard to remove crosstalk effects) across gate cycles by destroying intercycle coherent correlations. Second, it converts individual gate cycle errors into Pauli noise. Finally, randomized compiling reduces the variability inherent to noisy devices. We confirm these theoretical predictions with the IBM Quantum Experience platform and describe experimental data that illustrates a drastic performance improvement across public devices. These results cement the importance of randomized compiling in near- and long-term quantum information processing.