Efficient quantum circuits based on the quantum natural gradient

Efficient preparation of arbitrary entangled quantum states is crucial for quantum computation. This is particularly important for noisy intermediate-scale quantum simulators relying on variational hybrid quantum-classical algorithms. To that end, we propose symmetry-conserving modified quantum appr...

Full description

Saved in:
Bibliographic Details
Main Authors: Ananda Roy, Sameer Erramilli, Robert M. Konik
Format: Article
Language:English
Published: American Physical Society 2024-11-01
Series:Physical Review Research
Online Access:http://doi.org/10.1103/PhysRevResearch.6.043083
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1850178486026633216
author Ananda Roy
Sameer Erramilli
Robert M. Konik
author_facet Ananda Roy
Sameer Erramilli
Robert M. Konik
author_sort Ananda Roy
collection DOAJ
description Efficient preparation of arbitrary entangled quantum states is crucial for quantum computation. This is particularly important for noisy intermediate-scale quantum simulators relying on variational hybrid quantum-classical algorithms. To that end, we propose symmetry-conserving modified quantum approximate optimization algorithm (SCom-QAOA) circuits. The depths of these circuits depend not only on the desired fidelity to the target state but also on the amount of entanglement the state contains. The parameters of the SCom-QAOA circuits are optimized using the quantum natural gradient method based on the Fubini-Study metric. The SCom-QAOA circuit transforms an unentangled state into a ground state of a gapped one-dimensional Hamiltonian with a circuit depth that depends not on the system size but rather on the finite correlation length. In contrast, the circuit depth grows proportionally to the system size for preparing low-lying states of critical one-dimensional systems. Even in the latter case, SCom-QAOA circuits with depth less than the system size were sufficient to generate states with fidelity in excess of 99%, which is relevant for near-term applications. The proposed scheme enlarges the set of the initial states accessible for variational quantum algorithms and widens the scope of investigation of nonequilibrium phenomena in quantum simulators.
format Article
id doaj-art-1aa28f0d8617407cbd8d585aec4d02c3
institution OA Journals
issn 2643-1564
language English
publishDate 2024-11-01
publisher American Physical Society
record_format Article
series Physical Review Research
spelling doaj-art-1aa28f0d8617407cbd8d585aec4d02c32025-08-20T02:18:43ZengAmerican Physical SocietyPhysical Review Research2643-15642024-11-016404308310.1103/PhysRevResearch.6.043083Efficient quantum circuits based on the quantum natural gradientAnanda RoySameer ErramilliRobert M. KonikEfficient preparation of arbitrary entangled quantum states is crucial for quantum computation. This is particularly important for noisy intermediate-scale quantum simulators relying on variational hybrid quantum-classical algorithms. To that end, we propose symmetry-conserving modified quantum approximate optimization algorithm (SCom-QAOA) circuits. The depths of these circuits depend not only on the desired fidelity to the target state but also on the amount of entanglement the state contains. The parameters of the SCom-QAOA circuits are optimized using the quantum natural gradient method based on the Fubini-Study metric. The SCom-QAOA circuit transforms an unentangled state into a ground state of a gapped one-dimensional Hamiltonian with a circuit depth that depends not on the system size but rather on the finite correlation length. In contrast, the circuit depth grows proportionally to the system size for preparing low-lying states of critical one-dimensional systems. Even in the latter case, SCom-QAOA circuits with depth less than the system size were sufficient to generate states with fidelity in excess of 99%, which is relevant for near-term applications. The proposed scheme enlarges the set of the initial states accessible for variational quantum algorithms and widens the scope of investigation of nonequilibrium phenomena in quantum simulators.http://doi.org/10.1103/PhysRevResearch.6.043083
spellingShingle Ananda Roy
Sameer Erramilli
Robert M. Konik
Efficient quantum circuits based on the quantum natural gradient
Physical Review Research
title Efficient quantum circuits based on the quantum natural gradient
title_full Efficient quantum circuits based on the quantum natural gradient
title_fullStr Efficient quantum circuits based on the quantum natural gradient
title_full_unstemmed Efficient quantum circuits based on the quantum natural gradient
title_short Efficient quantum circuits based on the quantum natural gradient
title_sort efficient quantum circuits based on the quantum natural gradient
url http://doi.org/10.1103/PhysRevResearch.6.043083
work_keys_str_mv AT anandaroy efficientquantumcircuitsbasedonthequantumnaturalgradient
AT sameererramilli efficientquantumcircuitsbasedonthequantumnaturalgradient
AT robertmkonik efficientquantumcircuitsbasedonthequantumnaturalgradient