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arxiv: 2604.26861 · v1 · submitted 2026-04-29 · 🪐 quant-ph

Recognition: unknown

Protein folding on a 64 qubit trapped-ion hardware via counterdiabatic quantum optimization

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Pith reviewed 2026-05-07 13:15 UTC · model grok-4.3

classification 🪐 quant-ph
keywords protein foldingquantum optimizationtrapped ionscounterdiabatic evolutionlattice modelspin glasshybrid workflowbias feedback
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The pith

Bias-field counterdiabatic optimization on 64 trapped-ion qubits produces lower-energy lattice protein configurations than random sampling.

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The paper shows that bias-field digitized counterdiabatic quantum optimization run on a 64-qubit trapped-ion processor can shift sampled energies downward for coarse-grained protein folding problems with 14 to 16 residues. These problems are encoded as dense higher-order Hamiltonians on a tetrahedral lattice that must satisfy backbone constraints while favoring residue contacts. Successive rounds feed low-energy samples back as longitudinal bias fields to guide the quantum evolution without variational parameters. A consensus post-processing step then merges the quantum contact signals with geometrically valid backbones to reach classical reference energies in several cases and beat random-seeded versions of the same pipeline. The demonstration establishes that this non-variational feedback loop can supply structured information at hardware scales previously unreported for trapped ions.

Core claim

BF-DCQO uses low-energy samples from each round to define longitudinal fields that steer subsequent quantum evolutions on 46-61 qubit instances of 14-16 residue peptides. The resulting distributions improve over uniform random sampling, most noticeably in the contact variables. When these samples enter a consensus pipeline that enforces feasible backbone geometries, the hybrid workflow reaches the classical reference energy on multiple instances and outperforms the corresponding random-seeded pipeline.

What carries the argument

Bias-field digitized counterdiabatic quantum optimization (BF-DCQO), a non-variational feedback loop in which low-energy samples from one evolution round set longitudinal bias fields for the next round, paired with a consensus post-processing pipeline that combines quantum contact predictions and feasible backbone geometries.

If this is right

  • Raw BF-DCQO samples already concentrate on lower energies than random sampling, particularly among residue-contact variables.
  • The hybrid workflow reaches classical reference energies on multiple 14-16 residue instances encoded with up to five-body terms.
  • Structured samples emerge at trapped-ion scales of 46-61 qubits for Hamiltonians that enforce both contact optimization and backbone constraints.
  • The non-variational bias feedback mechanism avoids parameter optimization while still guiding the evolution toward better regions.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

  • The same bias-feedback pattern could be tested on other dense combinatorial problems whose Hamiltonians contain long-range higher-order terms.
  • Increasing the number of bias rounds might further narrow the sampled distribution before post-processing is applied.
  • Hardware with native all-to-all connectivity, such as the reported barium ions, appears especially suited to the long-range interactions that appear in the lattice protein models.

Load-bearing premise

The consensus post-processing step that merges quantum contact information with feasible backbone geometries does not itself account for the reported energy improvements over random baselines.

What would settle it

Run the identical consensus post-processing pipeline on contact information drawn only from uniform random samples with no quantum data and check whether the final energies still reach the classical reference values reported for the BF-DCQO runs.

Figures

Figures reproduced from arXiv: 2604.26861 by Alejandro Gomez Cadavid, Ananth Kaushik, Claudio Girotto, Enrique Solano, Evgeny Epifanovsky, Hakan Doga, Hanna Linn, Martin Roetteler, Miguel Angel Lopez-Ruiz, Narendra N. Hegade, Panagiotis Kl. Barkoutsos, Pavle Nika\v{c}evi\'c, Pranav Chandarana, Sebasti\'an V. Romero.

Figure 1
Figure 1. Figure 1: Raw energy distributions for LEPFSGKALCSWSIC (53 qubits, high view at source ↗
Figure 3
Figure 3. Figure 3: Split-violin plot of consensus pipeline energy distributions across all 6 sequences (best pruning per sequence). Left half (blue): quantum (BF-DCQO); view at source ↗
Figure 4
Figure 4. Figure 4: Per-sample repair energy distributions for LEPFSGKALCSWSIC view at source ↗
read the original abstract

We report the largest trapped-ion hardware demonstration of lattice protein-folding optimization to date, using bias-field digitized counterdiabatic quantum optimization (BF-DCQO) on a fully connected 64-qubit Barium development system similar to the forthcoming IonQ Tempo line. Six peptide sequences with 14-16 amino-acid residues are encoded using a coarse-grained tetrahedral lattice model, yielding higher-order spin-glass Hamiltonians with long-range interactions involving up to five-body terms and mapped to 46-61 qubits. The resulting instances are demanding for near-term quantum hardware because low-energy configurations must satisfy backbone-geometry constraints while optimizing dense residue-contact interactions. BF-DCQO uses a non-variational bias-feedback mechanism, where low-energy samples from each round define longitudinal fields that guide subsequent quantum evolutions. Across the studied instances, BF-DCQO shifts raw sampled energy distributions toward lower energies than uniform random sampling, with the strongest improvements appearing in residue-contact variables. To preserve this signal, we introduce a consensus-based post-processing pipeline that combines quantum-learned contact information with feasible backbone geometries. The resulting hybrid workflow reaches the classical reference energy in multiple instances and improves over the corresponding random-seeded pipeline. These results show that BF-DCQO can generate structured samples for dense protein-folding Hamiltonians at previously unexplored trapped-ion scales.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Referee Report

2 major / 2 minor

Summary. The manuscript reports the largest trapped-ion hardware demonstration to date of lattice protein-folding optimization, using bias-field digitized counterdiabatic quantum optimization (BF-DCQO) on a 64-qubit Barium system. Six 14-16 residue peptides are encoded as higher-order spin-glass Hamiltonians (up to five-body terms) on 46-61 qubits. BF-DCQO is shown to shift raw sampled energy distributions lower than uniform random sampling, with strongest gains in residue-contact variables. A consensus-based post-processing pipeline then merges quantum-learned contacts with feasible backbone geometries, enabling the hybrid workflow to reach classical reference energies in multiple instances and to outperform the corresponding random-seeded pipeline.

Significance. If the structured samples generated by BF-DCQO are shown to be the primary source of the observed gains rather than an artifact of the classical post-processing, the work would constitute a meaningful step toward applying counterdiabatic quantum optimization to dense, long-range combinatorial problems at previously inaccessible trapped-ion scales. The bias-feedback mechanism and the hybrid pipeline design could serve as templates for future quantum-classical solvers in protein folding and related spin-glass instances.

major comments (2)
  1. [Results / Methods (post-processing pipeline)] The central performance claims rest on the hybrid workflow (abstract and Results section). The manuscript does not present an ablation in which the identical consensus post-processing pipeline is applied to samples drawn from uniform random sampling (or from a classical heuristic) without any BF-DCQO input. Without this control, it remains unclear whether the reported improvements over the random-seeded baseline are driven by structure in the quantum samples or by the classical merging and geometry-enforcement steps.
  2. [Results (energy distributions)] The raw energy-distribution shifts attributed to BF-DCQO (abstract and Figure 2 or equivalent) are presented without reported statistical tests, error bars on the distribution means, or quantification of run-to-run variability across the multiple rounds of bias feedback. This weakens the claim that BF-DCQO systematically produces lower-energy samples than random sampling for the contact variables.
minor comments (2)
  1. [Methods (Hamiltonian encoding)] The mapping from the tetrahedral lattice model to the qubit Hamiltonian (including the treatment of five-body terms) is only sketched; an explicit equation or supplementary table listing the interaction coefficients for at least one instance would improve reproducibility.
  2. [Methods (BF-DCQO)] Notation for the bias fields and the feedback schedule is introduced without a compact summary table; readers must cross-reference multiple paragraphs to reconstruct the precise BF-DCQO protocol.

Simulated Author's Rebuttal

2 responses · 0 unresolved

We thank the referee for their constructive and detailed comments. These have highlighted opportunities to strengthen the clarity and rigor of our presentation regarding the hybrid workflow and the evidence for BF-DCQO sample quality. We address each major comment below and will incorporate the suggested additions in the revised manuscript.

read point-by-point responses
  1. Referee: [Results / Methods (post-processing pipeline)] The central performance claims rest on the hybrid workflow (abstract and Results section). The manuscript does not present an ablation in which the identical consensus post-processing pipeline is applied to samples drawn from uniform random sampling (or from a classical heuristic) without any BF-DCQO input. Without this control, it remains unclear whether the reported improvements over the random-seeded baseline are driven by structure in the quantum samples or by the classical merging and geometry-enforcement steps.

    Authors: We acknowledge the value of this control. The manuscript already compares the full hybrid workflow (BF-DCQO samples plus consensus post-processing) against a random-seeded pipeline that applies the same consensus merging and geometry-enforcement steps. However, we agree that an explicit ablation applying the identical post-processing pipeline to purely uniform random samples (with no BF-DCQO input at any stage) would more cleanly isolate the contribution of structured quantum samples. We will add this ablation to the revised Results section, reporting the energies obtained when the consensus pipeline is seeded exclusively with random samples. This will allow direct comparison and confirm that the observed gains originate from the bias-feedback mechanism rather than the classical steps alone. revision: yes

  2. Referee: [Results (energy distributions)] The raw energy-distribution shifts attributed to BF-DCQO (abstract and Figure 2 or equivalent) are presented without reported statistical tests, error bars on the distribution means, or quantification of run-to-run variability across the multiple rounds of bias feedback. This weakens the claim that BF-DCQO systematically produces lower-energy samples than random sampling for the contact variables.

    Authors: We agree that the current presentation would benefit from greater statistical rigor. In the revised manuscript we will augment the energy-distribution analysis (Figure 2 and associated text) with error bars on the reported means, run-to-run standard deviations across the bias-feedback rounds, and appropriate statistical tests (e.g., two-sample t-tests or Wilcoxon rank-sum tests with p-values) comparing the BF-DCQO and uniform-random distributions for both total energy and the contact-variable subset. These additions will quantify the systematic shift and variability, thereby strengthening the evidence that BF-DCQO produces lower-energy samples than random sampling. revision: yes

Circularity Check

0 steps flagged

No significant circularity; iterative bias feedback compared to random baseline

full rationale

The derivation chain is self-contained. BF-DCQO bias fields are iteratively defined from prior-round low-energy samples, but the paper explicitly compares resulting energy distributions and post-processed outcomes against uniform random sampling under the identical consensus pipeline. This control prevents the final improvements from reducing to the inputs by construction. No equations equate a claimed prediction to a fitted parameter from the target data, and while the method likely cites prior author work on DCQO, the hardware demonstration at 46-61 qubits supplies independent empirical content. The post-processing is applied equally to quantum and random seeds, preserving the comparison.

Axiom & Free-Parameter Ledger

0 free parameters · 0 axioms · 0 invented entities

Based solely on the abstract, no explicit free parameters, axioms, or invented entities are stated; the bias fields are generated from sampled data rather than fitted constants, and the lattice model is a standard coarse-grained representation.

pith-pipeline@v0.9.0 · 5615 in / 1184 out tokens · 75530 ms · 2026-05-07T13:15:51.532663+00:00 · methodology

discussion (0)

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Reference graph

Works this paper leans on

37 extracted references · 22 canonical work pages · 1 internal anchor

  1. [1]

    Dill and Justin L

    K. A. Dill and J. L. MacCallum, “The protein-folding problem, 50 years on,”Science, vol. 338, no. 6110, pp. 1042–1046, 2012. [Online]. Available: https://www.science.org/doi/abs/10.1126/science.1219021

  2. [2]

    Principles that govern the folding of protein chains,

    C. B. Anfinsen, “Principles that govern the folding of protein chains,” Science, vol. 181, no. 4096, pp. 223–230, 1973. [Online]. Available: https://www.science.org/doi/abs/10.1126/science.181.4096.223

  3. [3]

    Finding low-energy conformations of lattice protein models by quantum annealing,

    A. Perdomo-Ortiz, N. Dickson, M. Drew-Brook, G. Rose, and A. Aspuru-Guzik, “Finding low-energy conformations of lattice protein models by quantum annealing,”Scientific Reports, vol. 2, no. 1, p. 571,

  4. [4]
  5. [5]

    Resource-efficient quantum algorithm for protein folding,

    A. Robert, P. K. Barkoutsos, S. Woerner, and I. Tavernelli, “Resource-efficient quantum algorithm for protein folding,”npj Quantum Information, vol. 7, no. 1, p. 38, 2021. [Online]. Available: https://doi.org/10.1038/s41534-021-00368-4

  6. [6]

    Coarse-grained lattice protein folding on a quantum annealer,

    T. Babej, C. Ing, and M. Fingerhuth, “Coarse-grained lattice protein folding on a quantum annealer,” 2018. [Online]. Available: https://arxiv.org/abs/1811.00713

  7. [7]

    Digitized-counterdiabatic quantum approximate optimization algorithm,

    P. Chandarana, N. N. Hegade, K. Paul, F. Albarr ´an-Arriagada, E. Solano, A. del Campo, and X. Chen, “Digitized-counterdiabatic quantum approximate optimization algorithm,”Phys. Rev. Res., vol. 4, p. 013141, Feb 2022. [Online]. Available: https://link.aps.org/doi/10. 1103/PhysRevResearch.4.013141

  8. [8]

    Protein folding with an all- to-all trapped-ion quantum computer,

    S. V . Romero, A. G. Cadavid, P. Nika ˇcevi´c, E. Solano, N. N. Hegade, M. A. Lopez-Ruiz, C. Girotto, M. Yamada, P. K. Barkoutsos, A. Kaushik, and M. Roetteler, “Protein folding with an all- to-all trapped-ion quantum computer,” 2025. [Online]. Available: https://arxiv.org/abs/2506.07866

  9. [9]

    Peptide conformational sampling using the quantum approximate optimization algorithm,

    S. Boulebnane, X. Lucas, A. Meyder, S. Adaszewski, and A. Montanaro, “Peptide conformational sampling using the quantum approximate optimization algorithm,”npj Quantum Information, vol. 9, no. 1, p. 70,

  10. [10]

    Available: https://doi.org/10.1038/s41534-023-00733-5

    [Online]. Available: https://doi.org/10.1038/s41534-023-00733-5

  11. [11]

    Resource analysis of quantum algorithms for coarse-grained protein folding models,

    H. Linn, I. Brundin, L. Garc ´ıa-´Alvarez, and G. Johansson, “Resource analysis of quantum algorithms for coarse-grained protein folding models,”Phys. Rev. Res., vol. 6, p. 033112, Jul 2024. [Online]. Available: https://link.aps.org/doi/10.1103/PhysRevResearch.6.033112

  12. [12]

    Protein structure prediction with high degrees of freedom in a gate-based quantum computer,

    J. V . Pamidimukkala, S. Bopardikar, A. Dakshinamoorthy, A. Kannan, K. Dasgupta, and S. Senapati, “Protein structure prediction with high degrees of freedom in a gate-based quantum computer,”Journal of Chemical Theory and Computation, vol. 20, no. 22, pp. 10 223–10 234, 11 2024. [Online]. Available: https://doi.org/10.1021/acs.jctc.4c00848

  13. [13]

    Quantum algorithm for protein structure prediction using the face-centered cubic lattice,

    R.-H. Li, H. Doga, B. Raubenolt, S. Mostame, N. DiSanto, F. Cumbo, J. Joshi, H. Linn, M. Gaffney, A. Holden, V . Kulkarni, V . Chaudhary, K. M. M. Jr, A. A. Saki, T. Radivoyevitch, F. DiFilippo, J. Qin, O. Shehab, and D. Blankenberg, “Quantum algorithm for protein structure prediction using the face-centered cubic lattice,” 2025. [Online]. Available: http...

  14. [14]

    Efficient quantum protein structure prediction with problem-agnostic ansatzes,

    H. Linn, R.-H. Li, A. Holden, A. A. Saki, F. DiFilippo, T. Radivoyevitch, D. Blankenberg, L. Garc ´ıa-´Alvarez, and G. Johansson, “Efficient quantum protein structure prediction with problem-agnostic ansatzes,”

  15. [15]

    Available: https://arxiv.org/abs/2509.18263

    [Online]. Available: https://arxiv.org/abs/2509.18263

  16. [16]

    A Quantum Approximate Optimization Algorithm

    E. Farhi, J. Goldstone, and S. Gutmann, “A quantum approximate optimization algorithm,” 2014. [Online]. Available: https://arxiv.org/abs/ 1411.4028

  17. [17]

    A variational eigenvalue solver on a photonic quantum processor,

    A. Peruzzo, J. McClean, P. Shadbolt, M.-H. Yung, X.-Q. Zhou, P. J. Love, A. Aspuru-Guzik, and J. L. O’Brien, “A variational eigenvalue solver on a photonic quantum processor,”Nature Communications, vol. 5, no. 1, p. 4213, 2014. [Online]. Available: https://doi.org/10. 1038/ncomms5213

  18. [18]

    Stochastic properties of the frequency dynamics in real and synthetic power grids,

    N. N. Hegade, X. Chen, and E. Solano, “Digitized counterdiabatic quantum optimization,”Phys. Rev. Res., vol. 4, p. L042030, Nov 2022. [Online]. Available: https://link.aps.org/doi/10.1103/PhysRevResearch. 4.L042030

  19. [19]

    Minimizing irreversible losses in quantum systems by local counterdiabatic driving,

    D. Sels and A. Polkovnikov, “Minimizing irreversible losses in quantum systems by local counterdiabatic driving,”Proceedings of the National Academy of Sciences, vol. 114, no. 20, pp. E3909–E3916,

  20. [20]

    Proceedings of the National Academy of Sciences120(33) (2023) https://doi.org/10.1073/pnas

    [Online]. Available: https://www.pnas.org/doi/abs/10.1073/pnas. 1619826114

  21. [21]

    Floquet- engineering counterdiabatic protocols in quantum many-body systems,

    P. W. Claeys, M. Pandey, D. Sels, and A. Polkovnikov, “Floquet- engineering counterdiabatic protocols in quantum many-body systems,” Phys. Rev. Lett., vol. 123, p. 090602, Aug 2019. [Online]. Available: https://link.aps.org/doi/10.1103/PhysRevLett.123.090602

  22. [22]

    Bias-field digitized counterdiabatic quantum optimization,

    A. G. Cadavid, A. Dalal, A. Simen, E. Solano, and N. N. Hegade, “Bias-field digitized counterdiabatic quantum optimization,” Phys. Rev. Res., vol. 7, p. L022010, Apr 2025. [Online]. Available: https://link.aps.org/doi/10.1103/PhysRevResearch.7.L022010

  23. [23]

    Bias-field digitized counterdiabatic quantum algorithm for higher-order binary optimization,

    S. V . Romero, A.-M. Visuri, A. G. Cadavid, A. Simen, E. Solano, and N. N. Hegade, “Bias-field digitized counterdiabatic quantum algorithm for higher-order binary optimization,”Communications Physics, vol. 8, no. 1, p. 348, 2025. [Online]. Available: https: //doi.org/10.1038/s42005-025-02270-3

  24. [24]

    Experimental comparison of two quantum computing architectures,

    N. M. Linke, D. Maslov, M. Roetteler, S. Debnath, C. Figgatt, K. A. Landsman, K. Wright, and C. Monroe, “Experimental comparison of two quantum computing architectures,”Proceedings of the National Academy of Sciences, vol. 114, no. 13, pp. 3305–3310, 2017

  25. [25]

    Estimation of effective interresidue contact energies from protein crystal structures: quasi-chemical approximation,

    S. Miyazawa and R. L. Jernigan, “Estimation of effective interresidue contact energies from protein crystal structures: quasi-chemical approximation,”Macromolecules, vol. 18, no. 3, pp. 534–552, 03 1985. [Online]. Available: https://doi.org/10.1021/ma00145a039

  26. [26]

    T. U. Consortium. (2025) Masti polpi (polybia-mastoparan-i), *polybia paulista* — uniprotkb entry p0c1q4. Protein evidence at protein level; 14 amino acids; antimicrobial and chemotactic peptide for polymorphonucleated leukocytes. :contentReference[oaicite:0]index=0. [Online]. Available: https://www.uniprot.org/uniprotkb/P0C1Q4/entry

  27. [27]

    10 structure ensemble of the 14-residue peptide rg-kwty-ng-itye-gr (mbh12) (pdb id: 1k43),

    M. T. Pastor, M. Lopez de la Paz, E. Lacroix, L. Serrano, and E. Perez-Paya, “10 structure ensemble of the 14-residue peptide rg-kwty-ng-itye-gr (mbh12) (pdb id: 1k43),” 2001, pDB entry 1K43. [Online]. Available: https://www.rcsb.org/structure/1K43

  28. [28]

    Mapping the orientation of helices in micelle-bound peptides by paramagnetic relaxation waves,

    M. Respondek, T. Madl, C. Goebl, R. Golser, and K. Zangger, “Mapping the orientation of helices in micelle-bound peptides by paramagnetic relaxation waves,”Journal of the American Chemical Society, vol. 129, no. 17, pp. 5228–5234, 2007, pDB entry: 2JMY; method: solution NMR; CM15 in DPC micelles; 15 residues

  29. [29]

    T. U. Consortium. (2025) Tissue transglutaminase (tgm2), homo sapiens (human) — uniprotkb entry q9bxq0. UniProtKB/Swiss- Prot; entry version 205 (updated 2025-07-01). [Online]. Available: https://www.uniprot.org/uniprotkb/Q9BXQ0/entry

  30. [30]

    (2025) Mitochondrial-derived peptide mots-c (mt-rnr1), homo sapiens (human) — uniprotkb entry a0a0c5b5g6

    ——. (2025) Mitochondrial-derived peptide mots-c (mt-rnr1), homo sapiens (human) — uniprotkb entry a0a0c5b5g6. UniProtKB/Swiss- Prot; entry version 29 (updated 2025-06-18). [Online]. Available: https://www.uniprot.org/uniprotkb/A0A0C5B5G6/entry

  31. [31]

    Nmr structure ofvg16krkp, an antimicrobial peptide in lipopolysaccharide (lps),

    A. Bhunia, A. Datta, C. Airoldi, P. Sperandeo, K. H. Mroue, J. Jimenez- Barbero, P. Kundu, and A. Ramamoorthy, “Nmr structure ofvg16krkp, an antimicrobial peptide in lipopolysaccharide (lps),”Scientific Reports, vol. 5, p. 11951, 2015, pDB entry: 2MWL; method: solution NMR; submitted 2014-11-13; released 2014-12-24; latest revision May 15, 2024

  32. [32]

    Efficient digitized counterdiabatic quantum optimization algorithm within the impulse regime for portfolio optimization,

    A. G. Cadavid, I. Montalban, A. Dalal, E. Solano, and N. N. Hegade, “Efficient digitized counterdiabatic quantum optimization algorithm within the impulse regime for portfolio optimization,”Phys. Rev. Appl., vol. 22, p. 054037, Nov 2024. [Online]. Available: https://link.aps.org/doi/10.1103/PhysRevApplied.22.054037

  33. [33]

    doi:10.22331/q-2024-11-07-1516 , url =

    J.-S. Chen, E. Nielsen, M. Ebert, V . Inlek, K. Wright, V . Chaplin, A. Maksymov, E. P ´aez, A. Poudel, P. Maunz, and J. Gamble, “Benchmarking a trapped-ion quantum computer with 30 qubits,” Quantum, vol. 8, p. 1516, Nov. 2024. [Online]. Available: https: //doi.org/10.22331/q-2024-11-07-1516

  34. [34]

    Scalable multispecies ion transport in a grid-based surface-electrode trap,

    R. D. Delaney, L. R. Sletten, M. J. Cich, B. Estey, M. I. Fabrikant, D. Hayes, I. M. Hoffman, J. Hostetter, C. Langer, S. A. Moses, A. R. Perry, T. A. Peterson, A. Schaffer, C. V olin, G. Vittorini, and W. C. Burton, “Scalable multispecies ion transport in a grid-based surface- electrode trap,”Phys. Rev. X, vol. 14, p. 041028, Nov 2024. [Online]. Availabl...

  35. [35]

    Doppler- free, multiwavelength acousto-optic deflector for two-photon addressing arrays of Rb atoms in a quantum information processor,

    S. Kim, R. R. McLeod, M. Saffman, and K. H. Wagner, “Doppler- free, multiwavelength acousto-optic deflector for two-photon addressing arrays of Rb atoms in a quantum information processor,”Appl. Opt., vol. 47, no. 11, pp. 1816–1831, Apr. 2008

  36. [36]

    Compact Ion-Trap Quantum Computing Demonstrator,

    I. Pogorelov, T. Feldker, C. D. Marciniak, L. Postler, G. Jacob, O. Krieglsteiner, V . Podlesnic, M. Meth, V . Negnevitsky, M. Stadler et al., “Compact Ion-Trap Quantum Computing Demonstrator,”PRX Quantum, vol. 2, no. 2, p. 020343, Jun. 2021

  37. [37]

    Enhancing quantum computer performance via symmetrization,

    A. Maksymov, J. Nguyen, Y . Nam, and I. Markov, “Enhancing quantum computer performance via symmetrization,” 2023. [Online]. Available: https://arxiv.org/abs/2301.07233