Enhanced measurements on quantum computers via the simultaneous probing of non-commuting Pauli operators
- 1Department of Physics and Astronomy, University of Exeter, Stocker Road, Exeter EX4 4QL, UK
- 2Institute for Quantum Computing, University of Waterloo, Waterloo, ON N2L 3G1, Canada
- 3Department of Combinatorics & Optimization, University of Waterloo, Waterloo, ON N2L 3G1, Canada
Abstract
Measuring the state of quantum computers is a highly non-trivial task, with implications for virtually all quantum algorithms. A promising avenue is multi-copy schemes, where identical copies of a quantum state are measured jointly so that all Pauli operators within the considered observable can be simultaneously assessed. Here, we present a first implementation of such a two-copy scheme in a measurement protocol. Based on Bayesian statistics, it accurately estimates not only the average of the desired observable but also the error en route. This enables an adaptive shot-allocation algorithm that preferentially samples the most uncertain Pauli terms. In regimes with many non-commuting Pauli operators, this “double'' scheme can outperform the state-of-the-art measurement protocol in minimizing total shots for a given precision. We also numerically confirm the finding in previous theoretical works that the two-copy scheme incurs an overhead due to the square-root relationship between the variance of measured quantities and the number of measurement shots.
Related
- Simultaneous measurements of enzyme propagation and biopolymer mobility elucidate the directional degradation of a dense biopolymer matrix
- Combinations of measurements that are simultaneous fits of parameters of interest and systematic uncertainties using the BLUE method
- Quantum simultaneous decoding via pretty-good measurements of tilted states
- Simultaneous measurements of N-subjettiness observables in jets from gluons and light-flavour quarks, and in decays of boosted W bosons and top quarks
- Spiral motion enables simultaneous homogenization and enhanced transport in granular pipe flow
BibTeX
@article{simon2026enhanced,
title = {{Enhanced measurements on quantum computers via the simultaneous probing of non-commuting Pauli operators}},
author = {Rick P. A. Simon and Zheng Shi and Charlie Nation and Andrew Jena and Luca Dellantonio},
journal = {Quantum},
year = {2026},
month = oct,
doi = {10.22331/q-2026-10-07-2229},
url = {https://quantum-journal.org/papers/q-2026-10-07-2229/},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Enhanced measurements on quantum computers via the simultaneous probing of non-commuting Pauli operators
AU - Rick P. A. Simon
AU - Zheng Shi
AU - Charlie Nation
AU - Andrew Jena
AU - Luca Dellantonio
PY - 2026
DA - 2026/10/07
JO - Quantum
DO - 10.22331/q-2026-10-07-2229
UR - https://quantum-journal.org/papers/q-2026-10-07-2229/
AB - Measuring the state of quantum computers is a highly non-trivial task, with implications for virtually all quantum algorithms. A promising avenue is multi-copy schemes, where identical copies of a quantum state are measured jointly so that all Pauli operators within the considered observable can be simultaneously assessed. Here, we present a first implementation of such a two-copy scheme in a measurement protocol. Based on Bayesian statistics, it accurately estimates not only the average of the desired observable but also the error en route. This enables an adaptive shot-allocation algorithm that preferentially samples the most uncertain Pauli terms. In regimes with many non-commuting Pauli operators, this “double'' scheme can outperform the state-of-the-art measurement protocol in minimizing total shots for a given precision. We also numerically confirm the finding in previous theoretical works that the two-copy scheme incurs an overhead due to the square-root relationship between the variance of measured quantities and the number of measurement shots.
SN - 2521-327X
ER -