Evaluating Energy Differences on a Quantum Computer with Robust Phase Estimation

Journal Article · 24 May 2021 · Physical Review Letters

DOI:https://doi.org/10.1103/physrevlett.126.210501· OSTI ID:1787512

Russo, Antonio E. ^[1]; Rudinger, Kenneth Michael ^[1]; Morrison, Benjamin C. A. ^[2]; Baczewski, Andrew David ^[2]

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1. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
2. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Univ. of New Mexico, Albuquerque, NM (United States)

Here, we adapt the robust phase estimation algorithm to the evaluation of energy differences between two eigenstates using a quantum computer. This approach does not require controlled unitaries between auxiliary and system registers or even a single auxiliary qubit. As a proof of concept, we calculate the energies of the ground state and low-lying electronic excitations of a hydrogen molecule in a minimal basis on a cloud quantum computer. The denominative robustness of our approach is then quantified in terms of a high tolerance to coherent errors in the state preparation and measurement. Conceptually, we note that all quantum phase estimation algorithms ultimately evaluate eigenvalue differences.

• Research Organization: Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA); USDOE Office of Science (SC), Advanced Scientific Computing Research (ASCR)
• Grant/Contract Number: AC04-94AL85000; NA0003525
• OSTI ID: 1787512
• Report Number(s): SAND--2020-7209J; 687368
• Journal Information: Physical Review Letters, Journal Name: Physical Review Letters Journal Issue: 21 Vol. 126; ISSN 0031-9007
• Publisher: American Physical Society (APS)
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
quantum algorithms
quantum simulation