CitationΒΆ
If you use QuGrad please cite the accompanying paper:
Long, C.K., Mayhall, N.J., Economou, S.E. et al. Minimal state-preparation times for silicon spin qubits. npj Quantum Inf 11, 113 (2025). https://doi.org/10.1038/s41534-025-01027-8
@Article{Long2025,
author={Long, Christopher K.
and Mayhall, Nicholas J.
and Economou, Sophia E.
and Barnes, Edwin
and Barnes, Crispin H. W.
and Martins, Frederico
and Arvidsson-Shukur, David R. M.
and Mertig, Normann},
title={Minimal state-preparation times for silicon spin qubits},
journal={npj Quantum Information},
year={2025},
month={Jul},
day={05},
volume={11},
number={1},
pages={113},
abstract={Efficient preparation of quantum states on noisy intermediate-scale quantum processors remains a significant challenge to achieve quantum advantage. While gate-based methods have been the traditional approach, pulse-based algorithms offer promising alternatives with finer control and potentially reduced overheads. Here, we leverage the concept of minimum evolution time (MET) as a fundamental metric for evaluating and benchmarking quantum-state-preparation efficiency. Using numerical modeling, we investigate METs achievable through optimized microwave and exchange pulse sequences on silicon quantum hardware. We focus our investigations on molecular ground states and arbitrary state transitions. Our results demonstrate remarkably low METs: 2.3 ns for H2, 4.6 ns for HeH+, and 27 ns for LiH. METs consistently remain below 50 ns for arbitrary four-qubit state transitions, outperforming gate-based methods. We perform further analyses, revealing the impact of silicon device parameters on MET performance. Notably, increasing the maximal exchange amplitude from 10 MHz to 1 GHz significantly reduces METs, while higher maximal microwave drive amplitudes lead to faster state transitions. These findings surpass results reported for other quantum architectures. Our numerical analysis also demonstrates reasonable robustness of pulse-based state preparation to device imperfections and leakage. Our study contributes to developing efficient quantum-simulation techniques and provides insights into the strengths of silicon quantum hardware.},
issn={2056-6387},
doi={10.1038/s41534-025-01027-8},
url={https://doi.org/10.1038/s41534-025-01027-8}
}
TY - JOUR
AU - Long, Christopher K.
AU - Mayhall, Nicholas J.
AU - Economou, Sophia E.
AU - Barnes, Edwin
AU - Barnes, Crispin H. W.
AU - Martins, Frederico
AU - Arvidsson-Shukur, David R. M.
AU - Mertig, Normann
PY - 2025
DA - 2025/07/05
TI - Minimal state-preparation times for silicon spin qubits
JO - npj Quantum Information
SP - 113
VL - 11
IS - 1
AB - Efficient preparation of quantum states on noisy intermediate-scale quantum processors remains a significant challenge to achieve quantum advantage. While gate-based methods have been the traditional approach, pulse-based algorithms offer promising alternatives with finer control and potentially reduced overheads. Here, we leverage the concept of minimum evolution time (MET) as a fundamental metric for evaluating and benchmarking quantum-state-preparation efficiency. Using numerical modeling, we investigate METs achievable through optimized microwave and exchange pulse sequences on silicon quantum hardware. We focus our investigations on molecular ground states and arbitrary state transitions. Our results demonstrate remarkably low METs: 2.3 ns for H2, 4.6 ns for HeH+, and 27 ns for LiH. METs consistently remain below 50 ns for arbitrary four-qubit state transitions, outperforming gate-based methods. We perform further analyses, revealing the impact of silicon device parameters on MET performance. Notably, increasing the maximal exchange amplitude from 10 MHz to 1 GHz significantly reduces METs, while higher maximal microwave drive amplitudes lead to faster state transitions. These findings surpass results reported for other quantum architectures. Our numerical analysis also demonstrates reasonable robustness of pulse-based state preparation to device imperfections and leakage. Our study contributes to developing efficient quantum-simulation techniques and provides insights into the strengths of silicon quantum hardware.
SN - 2056-6387
UR - https://doi.org/10.1038/s41534-025-01027-8
DO - 10.1038/s41534-025-01027-8
ID - Long2025
ER -
Additionally, you can reference this code base specifically with the following citation:
Long C.K., Barnes C.H.W., Mertig N. (2025). QuGrad (version 1.0.2). DOI: 10.5281/zenodo.17116721 URL: https://github.com/Christopher-K-Long/QuGrad
@misc{YourReferenceHere,
author = {Long, Christopher K. and Barnes, Crispin H. W. and Mertig, Normann},
doi = {10.5281/zenodo.17116721},
month = {10},
title = {QuGrad},
url = {https://github.com/Christopher-K-Long/QuGrad},
year = {2025}
}
TY - GEN
AB - A Python package for quantum optimal control.
AU - Long, Christopher K.
AU - Barnes, Crispin H. W.
AU - Mertig, Normann
DA - 2025-10-19
DO - 10.5281/zenodo.17116721
KW - quantum
KW - optimal
KW - control
PY - 2025
TI - QuGrad
UR - https://github.com/Christopher-K-Long/QuGrad
ER
%0 Generic
%A Long, Christopher K.
%A Barnes, Crispin H. W.
%A Mertig, Normann
%D 2025
%K quantum
%K optimal
%K control
%R 10.5281/zenodo.17116721
%T QuGrad
%U https://github.com/Christopher-K-Long/QuGrad
{
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"legalName": "University of Cambridge and Hitachi Cambridge Laboratory"
},
"familyName": "Long",
"givenName": "Christopher K."
},
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"givenName": "Crispin H. W."
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"identifier": "https://doi.org/10.5281/zenodo.17116721",
"keywords": [
"quantum",
"optimal",
"control"
],
"license": "https://spdx.org/licenses/Apache-2.0",
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"version": "1.0.2"
}
cff-version: 1.2.0
title: QuGrad
message: >-
If you use QuGrad, please cite the accompanying paper:
Long, C.K., Mayhall, N.J., Economou, S.E. et al. Minimal state-preparation
times for silicon spin qubits. npj Quantum Inf 11, 113 (2025).
https://doi.org/10.1038/s41534-025-01027-8
Additionally, you can reference this code base using this CFF file.
type: software
authors:
- given-names: Christopher K.
family-names: Long
email: ckl45@cam.ac.uk
affiliation: University of Cambridge and Hitachi Cambridge Laboratory
orcid: 'https://orcid.org/0009-0001-3230-942X'
- given-names: Crispin H. W.
family-names: Barnes
affiliation: University of Cambridge
orcid: 'https://orcid.org/0000-0001-7337-7245'
- given-names: Normann
family-names: Mertig
affiliation: Hitachi Cambridge Laboratory
orcid: 'https://orcid.org/0000-0003-3025-7141'
repository-code: 'https://github.com/Christopher-K-Long/QuGrad'
url: 'https://github.com/Christopher-K-Long/QuGrad'
abstract: A Python package for quantum optimal control.
keywords:
- quantum
- optimal
- control
identifiers:
- description: Archives of each released version
type: doi
value: "10.5281/zenodo.17116721"
license: Apache-2.0
version: 1.0.2
date-released: '2025-10-19'