2021/03/12 by Hsin-Yuan Huang, Richard Kueng, John Preskill · 1 citation
Computer Science · Mathematics · Physics and Astronomy · #Hadron #Mathematical Analysis and Transform Methods #Nuclear physics #Observable #Particle physics #Pauli exclusion principle #Physics #Quantum Computing Algorithms and Architecture #Quantum chaos and dynamical systems #Quantum mechanics #Statistical physics #cs.DS #quant-ph
paper · pdf · doi:10.1103/physrevlett.127.030503
published as Phys. Rev. Lett. 127, 030503 (2021) · 12 pages, 2 figures, 1 table; open-source code available at https://github.com/momohuang/predicting-quantum-properties
arxiv created 2021/03/12 · openalex publication_date 2021/07/16 · arxiv updated 2021/07/21 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06
We consider the problem of jointly estimating expectation values of many Pauli observables, a crucial subroutine in variational quantum algorithms. Starting with randomized measurements, we propose an efficient derandomization procedure that iteratively replaces random single-qubit measurements by fixed Pauli measurements; the resulting deterministic measurement procedure is guaranteed to perform at least as well as the randomized one. In particular, for estimating any L low-weight Pauli observables, a deterministic measurement on only of order log(L) copies of a quantum state suffices. In some cases, for example, when some of the Pauli observables have high weight, the derandomized procedure is substantially better than the randomized one. Specifically, numerical experiments highlight the advantages of our derandomized protocol over various previous methods for estimating the ground-state energies of small molecules.