Double-bracket quantum algorithms for high-fidelity ground state preparation

Journal article

Matteo Robbiati, Edoardo Pedicillo, Andrea Pasquale, Xiaoyue Li, Oriel Kiss, Andrew Wright, Renato M. S. Farias, Khanh Uyen Giang, Jeongrak Son, Johannes Knörzer, Siong Thye Goh, Jun Yong Khoo, Nelly H.Y. Ng, Zoë Holmes, Stefano Carrazza, Marek Gluza
arXiv, 2408.03987, 2025 Nov

DOI: https://doi.org/10.48550/arXiv.2408.03987

arXiv

Cite

APA Click to copy
Robbiati, M., Pedicillo, E., Pasquale, A., Li, X., Kiss, O., Wright, A., … Gluza, M. (2025). Double-bracket quantum algorithms for high-fidelity ground state preparation. ArXiv, 2408.03987. https://doi.org/ https://doi.org/10.48550/arXiv.2408.03987

Chicago/Turabian Click to copy
Robbiati, Matteo, Edoardo Pedicillo, Andrea Pasquale, Xiaoyue Li, Oriel Kiss, Andrew Wright, Renato M. S. Farias, et al. “Double-Bracket Quantum Algorithms for High-Fidelity Ground State Preparation.” arXiv 2408.03987 (November 2025).

MLA Click to copy
Robbiati, Matteo, et al. “Double-Bracket Quantum Algorithms for High-Fidelity Ground State Preparation.” ArXiv, vol. 2408.03987, Nov. 2025, doi: https://doi.org/10.48550/arXiv.2408.03987.

BibTeX Click to copy

@article{matteo2025a,
  title = {Double-bracket quantum algorithms for high-fidelity ground state preparation},
  year = {2025},
  month = nov,
  journal = {arXiv},
  volume = {2408.03987},
  doi = { 	 https://doi.org/10.48550/arXiv.2408.03987},
  author = {Robbiati, Matteo and Pedicillo, Edoardo and Pasquale, Andrea and Li, Xiaoyue and Kiss, Oriel and Wright, Andrew and Farias, Renato M. S. and Giang, Khanh Uyen and Son, Jeongrak and Knörzer, Johannes and Goh, Siong Thye and Khoo, Jun Yong and Ng, Nelly H.Y. and Holmes, Zoë and Carrazza, Stefano and Gluza, Marek},
  month_numeric = {11}
}

Ground state preparation is a central application for quantum computers but remains challenging in practice. In this work, we quantitatively investigate the performance and gate counts of double-bracket quantum algorithms (DBQAs) for ground state preparation. We propose a practical strategy in which DBQAs refine initial state preparation circuits, and we compile them for Heisenberg chains using controlled-Z and single-qubit gates. Warm-started DBQAs consistently improve both the energy and ground-state fidelity relative to the initial states provided by variational ansätze, indicating that DBQAs offer an effective unitary synthesis method. To demonstrate compatibility with near-term hardware, we executed a proof-of-concept example on IBM devices. With error mitigation, we observed a statistically significant improvement over the corresponding warm-start circuit. Furthermore, numerical emulations for the same system size indicate that executing DBQAs on Quantinuum's hardware could achieve similar cost-function gains without requiring error mitigation. These findings suggest that DBQAs are a promising approach for enhancing ground-state approximations on near-term quantum devices.