Work

Characterizing correlated noise with single-qubit operations

Year: 2025

Type: article

Abstract: Spatially correlated noise poses a significant challenge to fault-tolerant quantum computation by breaking the assumption of independent errors. Existing methods such as cycle benchmarking and quantum process tomography can characterize noise correlations but require substantial resources. We propose straightforward and efficient techniques to detect and quantify these correlations by leveraging collective phenomena arising from environmental correlations in a qubit register. In these techniques, single-qubit state preparations, single-qubit gates, and single-qubit measurements, combined with classical postprocessing, suffice to uncover correlated relaxation and dephasing. Specifically, we use that correlated relaxation is connected to the superradiance effect, which we show to be accessible by single-qubit measurements. Analogously, the established parity oscillation protocol can be refined to quantify correlated dephasing without requiring the preparation of complex and entangled states.

Source: Physical Review Research

DOI: 10.1103/k2lx-vfqp

Authors: Balázs Gulácsi, Joris Kattemölle, Guido Burkard

Institution: University of Konstanz

Language: English

Topic: Quantum Computing Algorithms and Architecture

Subfield: Artificial Intelligence

Field: Computer Science

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $2,625

Funders: Deutsche Forschungsgemeinschaft, Ministerium für Wirtschaft, Arbeit und Wohnungsbau Baden-Württemberg