REVIEW 3 major objections 4 minor 1 cited by
Interaction-resolved decomposition of multi-qubit unitaries via computational-basis phases
T0 review · 3 major / 4 minor · reviewed 2026-08-02 · deepseek-v4-flash
Pith's one-line read A parity-weighted sum of computational-basis phases exactly isolates every k-body interaction in a locally diagonalizable n-qubit unitary, turning multi-qubit gate synthesis into a diagonal-frame control problem.
desk verdict Sound control framework with a real branch-ambiguity flaw in the 'unique invariants' claim; fixable and worth refereeing. read the letter →
The pith
A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.
The reading
What carries the argument
The central object is the support-selective phase invariant Δ_S(ϕ), a signed parity average of the diagonal phase values: Δ_S(ϕ) = (−1)^{|S|}2^{-−n} Σ_x (−1)^{Σ_{i∈S} x_i} ϕ(x). It acts as an exact filter on the Walsh–Hadamard expansion of the phase map, returning only the k-body component supported on the subset S. The invariant carries the argument: it converts multi-qubit interaction structure into individually addressable scalar targets, and since it is differentiable in the phases it plugs directly into a control cost function. The second ingredient is the diagonalizing frame V: the invariants describe physical interactions only when V is local for the operations of interest, which the
What would settle it
Take an entangling unitary that is not locally diagonalizable and compute the phase invariants Δ_S in two different diagonalizing frames; if the extracted k-body coefficients differ, the invariants are exact only as frame coordinates, not as physical interaction content. For the NV demonstration, rerun the pulse optimization with the auxiliary-manifold term H_0^(RWA)(t) included and check whether coherent nuclear rotations approach ~2θ_i; if they do, the reported fidelities of 0.9978 and 0.9985 are optimistic.
Extended reading notes
Core claim
The paper proves (Proposition 2) that for any diagonal phase map ϕ on {0,1}^n, the quantity Δ_S(ϕ) = 2^{-−|S̄|} Σ_{x_{S̄}} δ_S[ϕ(x_S, x_{S̄})] — equivalently (−1)^{|S|}2^{-−n} Σ_x (−1)^{Σ_{i∈S} x_i} ϕ(x) — equals the Walsh–Hadamard coefficient supported exactly on S and is invariant under adding any phase contribution supported on any other subset. The proof combines discrete derivatives that annihilate Walsh characters not containing S with averaging over complementary bits that kills characters containing S plus extra qubits. On this basis the authors define a π-periodic cost function over target values Δ*_S, allowing k-body-resolved optimal control. They use it to synthesize e^{i(π/4)ZZZ}
Load-bearing premise
The load-bearing premise is that the gate of interest is locally diagonalizable, so the computational-basis phase map and its k-body coefficients describe the physical interactions rather than the diagonalizing frame; in the NV demo the model also drops an auxiliary-manifold term that the authors' own Appendix C(j) says can coherently rotate nuclei by up to about 2θ_i over the pulse times, so the quoted fidelities are optimistic if that term is material.
Editorial extensions
If this is right
- If the invariants are exact, a control pulse can be optimized to realize a prescribed k-body interaction content (for example, a pure ZZZ term with zero ZZ terms) without ever specifying the full target unitary, avoiding over-constrained objectives.
- Characterization and cost evaluation scale with the 2^n diagonal phases of the gate in its diagonalizing frame, instead of the 4^n entries of a general unitary — a quadratic reduction in the number of parameters.
- For the simulated NV register, the invariants yield single-pulse ZZZ and XZZ entanglers in 1.5 µs and 1.25 µs with fidelities 0.9978 and 0.9985, respectively, which the authors estimate is 10–100 times faster than existing multi-qubit NV entanglers built from two-qubit gate sequences.
- The non-diagonal XZZ example shows the method is not limited to naturally diagonal gates: any gate with a local diagonalizing frame can be optimized inside that frame and transformed back.
- XZZ-type terms appear in stabilizer measurements, so this offers a direct route to faster syndrome extraction for quantum error correction.
Reading between the lines
- For a generic n-qubit unitary whose diagonalizing frame is entangling, the parity sums still yield a well-defined coordinate system, but the extracted k-body coefficients describe the frame's content, not the gate's physical interactions; a natural strategy the paper leaves implicit is to search over diagonalizing frames to minimize entanglement in V and thereby make the invariants physically mean
- Because each Δ_S is a linear combination of 2^n experimentally measurable phases, the same invariants could drive closed-loop calibration: measure the diagonal phases with the paper's |+⟩-basis probing, compute the invariants, and feed them back into the optimizer without full process tomography.
- Editorial note on the demonstration: the fidelity numbers should be read with the model's own caveat, stated in Appendix C(j), that the auxiliary-manifold term H_0^(RWA) can coherently rotate nuclei by up to about 2θ_i over pulses of 1–2 µs and is neglected; if that rotation is not negligible, the quoted fidelities are optimistic.
Editorial analysis
A structured set of objections, weighed in public.
Referee Report
Summary. The paper introduces a framework for decomposing the phase map of a diagonalized n-qubit unitary into k-body interaction contributions via parity-weighted sums (support-selective phase invariants). The theoretical core defines discrete derivative operators on the Boolean cube, proves (Prop. 1) that these annihilate Walsh characters not containing the support S, and (Prop. 2) that averaging over complementary variables isolates exactly the S-supported contribution. An alternating-sum form (Eq. 23, Appendix A) and explicit three-qubit formulas (Appendix B) are provided. The framework is then used to formulate a control cost function (Eq. 25) targeting selected k-body phases, and demonstrated numerically on a simulated NV-14N-13C-13C register: a diagonal ei(π/4)ZZZ gate at fidelity 0.9978 and a Hadamard-frame-synthesized ei(π/4)XZZ gate at fidelity 0.9985. The authors claim a 10-100x speedup over existing NV multi-qubit entanglers and argue the phase-invariant objective reduces characterization and optimization overhead.
Significance. If the central claim is made precise, the support-selective phase invariants are a genuinely useful coordinate system for locally diagonalizable multi-qubit gates. The algebraic derivations are clean and closed-form: Props. 1-2 and the Appendix A alternating-sum identity are exact linear identities, not fits to data, and the three-qubit formulas in Appendix B check out. The paper also ships reproducible code on Zenodo/GitHub (ref. [77]) and the reported fidelities are computed against the target unitary, an independent metric from the cost function, so I do not share the circularity concern. The broad 'n-qubit unitary' framing, however, is currently too strong: the decomposition is defined for a chosen diagonalizing frame and a chosen real lift of the phase map, and as stated the paper does not give a canonical lift. The phase-lift issue is load-bearing, because it affects even naturally diagonal gates and the claimed uniqueness of the k-body resolution. The numerical NV demonstration is also weakened by the explicit neglect of a term that the paper's own Appendix C(j) says can be material at the demonstrated pulse durations.
major comments (3)
- [Eq. (6), Prop. 2, Eq. (23)] There is a domain inconsistency that undermines the claim of uniqueness. Eq. (6) defines the phase map as φ:{0,1}^n→R/2πZ, but the Walsh expansion (7)-(8), the discrete derivatives (11)-(12), and the invariants (22)-(23) all require a chosen real-valued lift φ:{0,1}^n→R. The invariants are not invariant under adding 2π to a single phase value. For example, for n=3 the identity gate has the equivalent lifts φ≡0 and φ_000=2π (all other φ_x=0). The first gives all Δ_S=0; the second gives Δ_{abc}=-π/4 and each two-body Δ=π/4. Thus Proposition 2's statement that Δ_S 'returns precisely the contribution to φ supported on S' and is invariant under adding any phase contribution supported on R≠S is a statement about a chosen lift, not about the unitary defined by Eq. (6). The cost function (25) is not invariant under this physically irrelevant redefinition. The numerical simulations may implicitly
- [Sec. II.A.1, Eq. (1); Conclusion] The framework's physical meaning depends on the diagonalizing frame V being local for the operations of interest. For a generic n-qubit unitary, V is entangling, and the k-body coefficients of the phase map then describe the frame's content rather than the physical interaction structure of the gate. The paper's examples (single/commuting Pauli-string generators, controlled-phase, Ising, Hadamard-sandwiched XZZ) are all locally diagonalizable, but the abstract and conclusion claim the decomposition applies to 'n-qubit unitaries' and 'arbitrary n-qubit transformations.' This overstates the established scope: the decomposition is a property of the diagonal phase map in a fixed frame. I recommend either restricting the claims to locally diagonalizable targets or explicitly presenting the invariants as frame-relative quantities, which still has value for control but is not the same as an intr
- [Appendix C(j), Secs. III.B and III.C] The numerical model neglects the auxiliary-manifold nuclear term H_0^(RWA)(t). Appendix C(j) itself states that for pulse durations of ~1-2 µs these residual oscillations 'can accumulate small but coherent nuclear rotations (amplitude ≲ 2θ_i), and H_0^(RWA)(t) should then be retained in quantitative simulations.' The two demonstrations use T=1.5 µs and T=1.25 µs, precisely in this regime, yet the reported fidelities (Eqs. 36 and 45) are computed without that term. This makes the quantitative claim of a 'realistic' NV simulation and the quoted fidelities potentially optimistic. Please include the term in the simulations or estimate its effect for the specific θ_i values in Table I and show it is negligible.
minor comments (4)
- [Eq. (10)] The single-qubit line writes χ_{i,j}(x); this should be χ_i(x) (or χ_{\{i\}}(x)).
- [Figs. 2 and 5 captions] Fig. 2 says the three-body invariant converges to -3π/4, while the text (Sec. III.B) says Δ≈π/4 modulo π. Please state the π-periodicity convention explicitly here, since the reader must infer that -3π/4 and π/4 differ by π and are considered equivalent in the cost function.
- [Sec. IV] The conclusion contains a duplicated phrase: 'with reduced with reduced optimization overhead.' Also the sentence 'This reduces characterization costs quadratically with qubit number' should be reconciled with the scaling discussion in the Introduction (Θ(2^n) vs Θ(4^n) is an exponential reduction in the number of parameters, not a quadratic reduction in qubit number).
- [Throughout] The paper alternates between 'real-valued phase map' and 'phase map ϕ:{0,1}^n→R/2πZ.' Please standardize the terminology and explicitly state the lift convention used in the numerical simulations, ideally in Sec. II.A.1.
Circularity Check
No significant circularity: the phase invariants are exact linear identities, and reported fidelities use an independent target-unitary metric; the 2π-lift ambiguity is a correctness caveat, not a circular reduction.
full rationale
The central derivation (Prop. 2, Eqs. 22-23) is self-contained Boolean Fourier analysis: Δ_S(φ) is defined as an averaged discrete derivative, and the proof shows it annihilates all Walsh characters with support not exactly S and equals ±b_φ(S). This is an algebraic identity, not a fit or a prediction from fitted parameters. The target values Δ⋆_S in Eq. (33) are chosen from the target gate, but the reported F_ZZZ=0.9978 and F_XZZ=0.9985 are computed against the full target unitaries via Eqs. (36)/(45), an independent metric from the cost function J_3q. Physical parameters come from external literature (Table I, refs. [51,79]), and self-citations [10,15,26,47,77] are not used to justify the core theorem. The main caveat is the branch-lift issue: Eq. (6) defines φ:{0,1}^n→R/2πZ, while Eqs. (7)-(8) and Appendix A use real-valued phases, so a 2π shift of one phase value changes the Δ_S values (e.g., φ_000→φ_000+2π shifts every three- and two-body invariant by π/4). This makes 'unique' k-body content physically lift-dependent; however, it is a well-definedness/correctness problem, not circularity, because for any fixed lift the derivation is internally consistent. Appendix C(j)'s acknowledgment that the neglected auxiliary-manifold term can rotate nuclei by ≲2θ_i is an explicit model limitation and affects fidelity estimates, but does not make the derivation circular. Overall: no predicted quantity reduces to its input by construction.
Assumptions & free parameters
free parameters (4)
- Cost weights w_|S| (Eq. 25) =
not reported (demo: w_1=0, w_2,w_3>0)
- Tukey taper fraction α =
0.15
- Regularization strengths (leakage, non-unitarity, rapid-variation penalties) =
not specified
- CRAB tone count n and initial guesses (a_i, ω_i, φ_i) =
not stated
assumptions (7)
- standard math Any n-qubit unitary is diagonalizable (spectral theorem); the diagonal phase map fully characterizes U_diag in its frame
- standard math Every real function on the Boolean cube has a unique Walsh-Hadamard expansion
- domain assumption The diagonalizing frame V is local for the targeted operations
- domain assumption RWA and first-order small-angle (θ_i ≪ 1) expansion of the NV Hamiltonian; auxiliary-manifold nuclear wobble H_0^(RWA) neglected
- domain assumption NV register physical parameters from literature/typical ranges
- domain assumption π-periodic equivalence of phase invariants identifies physically equivalent interactions
- ad hoc to paper Time-integrated exposure model D = exp(−exposure/T2*) approximates dephasing loss
Cite this review
Pith. "Pith review of Interaction-resolved decomposition of multi-qubit unitaries via computational-basis phases." pith.science (2026). https://pith.science/paper/YFUMPGVX
@misc{pith2026260218375,
author = {Pith},
title = {Pith review of: Interaction-resolved decomposition of multi-qubit unitaries via computational-basis phases},
year = {2026},
howpublished = {\url{https://pith.science/paper/YFUMPGVX}},
note = {Machine review of arXiv:2602.18375}
}
read the original abstract
In multi-qubit quantum control, target unitary operations are commonly specified through full-unitary target descriptions and assessed through global comparison measures. In this work, we introduce an interaction-resolved decomposition of n-qubit unitaries that provides explicit access to their many-body interaction structure through computational-basis phases collected in a diagonalizing frame. Such a frame is conveniently given by local rotations for many operationally relevant operations, including gates generated by single Pauli strings or commuting sets of Pauli strings, such as stabilizer operations, controlled-phase gates, Toffoli-type operations, and Ising interactions. We derive parity-weighted sums of these computational-basis phases that exactly and uniquely resolve k-body interaction terms supported on arbitrary qubit subsets, which we term support-selective phase invariants. These invariants provide an interaction-resolved coordinate system that organizes unitary operations according to their multipartite interaction structure, giving direct access to local, pairwise, tripartite, and general k-partite interaction content underlying entangling operations. This enables the formulation of selective quantum optimal control targets for synthesizing desired combinations of many-body interactions. We supplement this with numerical demonstrations for a representative hardware model, a realistic nitrogen-vacancy spin register, where we synthesized isolated tripartite interactions up to local equivalence within a single control pulse, guided by these invariants, for both diagonal (ZZZ) and non-diagonal (XZZ) terms.
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Reference graph
Works this paper leans on
-
[77]
Fermionic quantum process- ing with programmable neutral atom arrays.Proceedings of the National Academy of Sciences, 120(35):e2304294120, 2023
Daniel González-Cuadra, Dolev Bluvstein, Marcin Kali- nowski, Raphael Kaubruegger, Nishad Maskara, Piero Naldesi, Torsten V Zache, Adam M Kaufman, Mikhail D Lukin, Hannes Pichler, et al. Fermionic quantum process- ing with programmable neutral atom arrays.Proceedings of the National Academy of Sciences, 120(35):e2304294120, 2023
2023
-
[1]
Diagonal Phase Map Any n-qubit unitary operator Utarget is diagonalizable [41], i.e., there exists a unitary transformationV such that Udiag =V Utarget V † = X ⃗ x∈{0,1}n eiϕ(⃗ x)|⃗ x⟩ ⟨⃗ x|.(1) While such a diagonalizing transformation need not be local, many operations of practical relevance in quantum control, such as gates generated by Pauli-product H...
-
[2]
Walsh Hadamard Expansion Next, we consider that such a phase mapϕ(⃗ x)is simply a real-valued function on the Boolean cube{0, 1}n; it therefore admits a standard representation in terms of Boolean Fourier analysis [43, 45]. In particular, any real- valued function on{0, 1}n has a unique expansion in the {±1}-valued characters, known as the Walsh-Hadamard ...
-
[3]
Here, we define for each qubit indexi∈ {1,
Discrete Derivatives The discrete derivative operator originally stems from the analysis of Boolean functions and provides a derivative for discrete functions on the binary hypercube [43]. Here, we define for each qubit indexi∈ {1, . . . , n}the normalized single qubit discrete derivative operator, as (δiϕ)(x1, . . . , xn) := 1 2 ϕ(x1, . . . , xi−1,1, . ....
-
[4]
Quantum optimal control in quan- tum technologies
Christiane P Koch, Ugo Boscain, Tommaso Calarco, Gun- ther Dirr, Stefan Filipp, Steffen J Glaser, Ronnie Kosloff, Simone Montangero, Thomas Schulte-Herbrüggen, Do- minique Sugny, et al. Quantum optimal control in quan- tum technologies. strategic report on current status, vi- sions and goals for research in europe.EPJ Quantum Technology, 9(1):19, 2022
2022
-
[5]
High-fidelity parallel entangling gates on a neutral- atom quantum computer.Nature, 622(7982):268–272, 2023
Simon J Evered, Dolev Bluvstein, Marcin Kalinowski, Sepehr Ebadi, Tom Manovitz, Hengyun Zhou, Sophie H Li, Alexandra A Geim, Tout T Wang, Nishad Maskara, et al. High-fidelity parallel entangling gates on a neutral- atom quantum computer.Nature, 622(7982):268–272, 2023
2023
-
[6]
Time- optimal control of a solid-state spin amidst dynamical quantum wind.npj Quantum Information, 10(1):108, 2024
Yang Dong, Wang Jiang, Xue-Dong Gao, Cui Yu, Yong Liu, Shao-Chun Zhang, Xiang-Dong Chen, Ibério de PR Moreira, Josep Maria Bofill, Gael Sentís, et al. Time- optimal control of a solid-state spin amidst dynamical quantum wind.npj Quantum Information, 10(1):108, 2024
2024
-
[7]
14-qubit entanglement: Creation and coherence.Physical Review Letters, 106(13):130506, 2011
Thomas Monz, Philipp Schindler, Julio T Barreiro, Michael Chwalla, Daniel Nigg, William A Coish, Max- imilian Harlander, Wolfgang Hänsel, Markus Hennrich, and Rainer Blatt. 14-qubit entanglement: Creation and coherence.Physical Review Letters, 106(13):130506, 2011
2011
Show all 84 references
-
[8]
Parallel implementation of high-fidelity multi- qubit gates with neutral atoms.Physical review letters, 123(17):170503, 2019
Harry Levine, Alexander Keesling, Giulia Semeghini, Ahmed Omran, Tout T Wang, Sepehr Ebadi, Hannes Bernien, Markus Greiner, Vladan Vuletić, Hannes Pich- ler, et al. Parallel implementation of high-fidelity multi- qubit gates with neutral atoms.Physical review letters, 123(17):...
2019
-
[9]
Generation and manipulation of schrödinger cat states in rydberg atom arrays.Science, 365(6453):570–574, 2019
Ahmed Omran, Harry Levine, Alexander Keesling, Giulia Semeghini, Tout T Wang, Sepehr Ebadi, Hannes Bernien, Alexander S Zibrov, Hannes Pichler, Soonwon Choi, et al. Generation and manipulation of schrödinger cat states in rydberg atom arrays.Science, 365(6453):570–574, 2019
2019
-
[10]
Hardware-efficient and fast three-qubit gate in superconducting quantum circuits.Frontiers of Physics, 19(5):51205, 2024
Xiao-Le Li, Ziyu Tao, Kangyuan Yi, Kai Luo, Libo Zhang, Yuxuan Zhou, Song Liu, Tongxing Yan, Yuanzhen Chen, and Dapeng Yu. Hardware-efficient and fast three-qubit gate in superconducting quantum circuits.Frontiers of Physics, 19(5):51205, 2024
2024
-
[11]
Microwave- activated high-fidelity three-qubit gate scheme for fixed- frequency superconducting qubits.Physical Review Ap- plied, 24(3):034064, 2025
Kui Zhao, Wei-Guo Ma, Ziting Wang, Hao Li, Kaixuan Huang, Yun-Hao Shi, Kai Xu, and Heng Fan. Microwave- activated high-fidelity three-qubit gate scheme for fixed- frequency superconducting qubits.Physical Review Ap- plied, 24(3):034064, 2025
2025
-
[12]
Fast microwave-driven three-qubit gates for cavity-coupled superconducting qubits.Physical Review B, 96(2):024504, 2017
Edwin Barnes, Christian Arenz, Alexander Pitchford, and Sophia E Economou. Fast microwave-driven three-qubit gates for cavity-coupled superconducting qubits.Physical Review B, 96(2):024504, 2017
2017
-
[13]
Exper- imental error suppression in cross-resonance gates via multi-derivative pulse shaping.npj Quantum Information, 10(1):66, 2024
Boxi Li, Tommaso Calarco, and Felix Motzoi. Exper- imental error suppression in cross-resonance gates via multi-derivative pulse shaping.npj Quantum Information, 10(1):66, 2024
2024
-
[14]
Ul- trafast single qubit gates through multi-photon transition removal.arXiv preprint arXiv:2511.22365, 2025
Y Gao, A Galicia, JD Jesus, Y Liu, Y Haddad, DA Volkov, JR Guimarães, H Bhardwaj, M Jerger, M Neis, et al. Ul- trafast single qubit gates through multi-photon transition removal.arXiv preprint arXiv:2511.22365, 2025
2025
-
[15]
Opti- mal control of fast and high-fidelity quantum gates with electron and nuclear spins of a nitrogen-vacancy center in diamond.Phys
Yi Chou, Shang-Yu Huang, and Hsi-Sheng Goan. Opti- mal control of fast and high-fidelity quantum gates with electron and nuclear spins of a nitrogen-vacancy center in diamond.Phys. Rev. A, 91:052315, May 2015
2015
-
[16]
Grace, Constantin Brif, Herschel Rabitz, Daniel A
Matthew D. Grace, Constantin Brif, Herschel Rabitz, Daniel A. Lidar, Ian A. Walmsley, and Robert L. Kosut. Fidelity of optimally controlled quantum gates with ran- domly coupled multiparticle environments.Journal of Modern Optics, 54(16-17):2339–2349, 2007
2007
-
[17]
Optimal control of families of quantum gates.Physical review letters, 129(5):050507, 2022
Frédéric Sauvage and Florian Mintert. Optimal control of families of quantum gates.Physical review letters, 129(5):050507, 2022
2022
-
[18]
Circuit design for a star-shaped spin- qubit processor via algebraic decomposition and optimal control.arXiv preprint arXiv:2506.16900, 2025
Yaqing X Wang, Tommaso Calarco, Felix Motzoi, and Matthias M Müller. Circuit design for a star-shaped spin- qubit processor via algebraic decomposition and optimal control.arXiv preprint arXiv:2506.16900, 2025
2025 arXiv
-
[19]
Optimalcontrol of coupled spin dynamics: design of nmr pulse sequences by gradient ascent algorithms.Journal of magnetic reso- nance, 172(2):296–305, 2005
Navin Khaneja, Timo Reiss, Cindie Kehlet, Thomas Schulte-Herbrüggen, andSteffenJGlaser. Optimalcontrol of coupled spin dynamics: design of nmr pulse sequences by gradient ascent algorithms.Journal of magnetic reso- nance, 172(2):296–305, 2005
2005
-
[20]
Second order gradient ascent pulse engineering.Journal of Magnetic Resonance, 212(2):412– 417, 2011
Pierre de Fouquieres, Sophie G Schirmer, Steffen J Glaser, and Ilya Kuprov. Second order gradient ascent pulse engineering.Journal of Magnetic Resonance, 212(2):412– 417, 2011
2011
-
[21]
Optimal control methods for rapidly time- varying hamiltonians.Physical Review A—Atomic, Molec- ular, and Optical Physics, 84(2):022307, 2011
F Motzoi, Jay M Gambetta, Seth T Merkel, and Frank K Wilhelm. Optimal control methods for rapidly time- varying hamiltonians.Physical Review A—Atomic, Molec- ular, and Optical Physics, 84(2):022307, 2011
2011
-
[22]
Spinach–a software library for simulation of spin dynamics in large spin systems.Journal of magnetic resonance, 208(2):179– 194, 2011
Hannah J Hogben, Matthew Krzystyniak, Gareth TP Charnock, Peter J Hore, and Ilya Kuprov. Spinach–a software library for simulation of spin dynamics in large spin systems.Journal of magnetic resonance, 208(2):179– 194, 2011
2011
-
[23]
Krotov: A python implemen- tation of krotov’s method for quantum optimal control
Michael Goerz, Daniel Basilewitsch, Fernando Gago- Encinas, Matthias G Krauss, Karl P Horn, Daniel M Reich, and Christiane Koch. Krotov: A python implemen- tation of krotov’s method for quantum optimal control. SciPost physics, 7(6):080, 2019
2019
-
[24]
Monotonically convergent optimization in quantum control using krotov’s method.The Journal of chemical physics, 136(10), 2012
Daniel M Reich, Mamadou Ndong, and Christiane P Koch. Monotonically convergent optimization in quantum control using krotov’s method.The Journal of chemical physics, 136(10), 2012
2012
-
[25]
Optimal control theory for a unitary operation under dissipative evolution.New Journal of Physics, 16(5):055012, 2014
Michael H Goerz, Daniel M Reich, and Christiane P Koch. Optimal control theory for a unitary operation under dissipative evolution.New Journal of Physics, 16(5):055012, 2014
2014
-
[26]
Chopped random-basis quantum optimiza- tion.Physical Review A—Atomic, Molecular, and Optical Physics, 84(2):022326, 2011
Tommaso Caneva, Tommaso Calarco, and Simone Mon- tangero. Chopped random-basis quantum optimiza- tion.Physical Review A—Atomic, Molecular, and Optical Physics, 84(2):022326, 2011
2011
-
[27]
Dressing the chopped-random-basis 12 optimization: A bandwidth-limited access to the trap-free landscape.Physical Review A, 92(6):062343, 2015
Niklas Rach, Matthias M Müller, Tommaso Calarco, and Simone Montangero. Dressing the chopped-random-basis 12 optimization: A bandwidth-limited access to the trap-free landscape.Physical Review A, 92(6):062343, 2015
2015
-
[28]
Optimal control technique for many-body quan- tum dynamics.Physical review letters, 106(19):190501, 2011
Patrick Doria, Tommaso Calarco, and Simone Mon- tangero. Optimal control technique for many-body quan- tum dynamics.Physical review letters, 106(19):190501, 2011
2011
-
[29]
One decade of quantum optimal control in the chopped random basis
Matthias Mueller, Ressa Suhardiman Said, Fedor Jelezko, Tommaso Calarco, and Simone Montangero. One decade of quantum optimal control in the chopped random basis. Reports on Progress in Physics, 2022
2022
-
[30]
Steffen J Glaser, Ugo Boscain, Tommaso Calarco, Chris- tiane P Koch, Walter Köckenberger, Ronnie Kosloff, Ilya Kuprov, Burkhard Luy, Sophie Schirmer, Thomas Schulte- Herbrüggen, et al. Training schrödinger’s cat: Quantum optimal control: Strategic report on current status, vi-...
2015
-
[31]
Continuous quantum gate sets and pulse-class meta- optimization.PRX Quantum, 3(4):040311, 2022
Francesco Preti, Tommaso Calarco, and Felix Motzoi. Continuous quantum gate sets and pulse-class meta- optimization.PRX Quantum, 3(4):040311, 2022
2022
-
[32]
Steering the optimization pathway in the control land- scape using constraints.Physical Review A—Atomic, Molecular, and Optical Physics, 88(5):053409, 2013
José P Palao, Daniel M Reich, and Christiane P Koch. Steering the optimization pathway in the control land- scape using constraints.Physical Review A—Atomic, Molecular, and Optical Physics, 88(5):053409, 2013
2013
-
[33]
Control of quantum phenomena: past, present and future
Constantin Brif, Raj Chakrabarti, and Herschel Rabitz. Control of quantum phenomena: past, present and future. New Journal of Physics, 12(7):075008, 2010
2010
-
[34]
Geometric theory of nonlocal two-qubit operations
Jun Zhang, Jiri Vala, Shankar Sastry, and K Birgitta Wha- ley. Geometric theory of nonlocal two-qubit operations. Physical Review A, 67(4):042313, 2003
2003
-
[35]
Counteracting systems of diabaticities using drag con- trols: The status after 10 years (a).Europhysics Letters, 123(6):60001, 2018
LS Theis, F Motzoi, S Machnes, and FK Wilhelm. Counteracting systems of diabaticities using drag con- trols: The status after 10 years (a).Europhysics Letters, 123(6):60001, 2018
2018
-
[36]
Shortcuts to adiabaticity: Con- cepts, methods, and applications.Reviews of Modern Physics, 91(4):045001, 2019
David Guéry-Odelin, Andreas Ruschhaupt, Anthony Kiely, Erik Torrontegui, Sofia Martínez-Garaot, and Juan Gonzalo Muga. Shortcuts to adiabaticity: Con- cepts, methods, and applications.Reviews of Modern Physics, 91(4):045001, 2019
2019
-
[37]
Classical feature map surrogates and metrics for quan- tum control landscapes.arXiv preprint arXiv:2509.25930, 2025
Martino Calzavara, Tommaso Calarco, and Felix Motzoi. Classical feature map surrogates and metrics for quan- tum control landscapes.arXiv preprint arXiv:2509.25930, 2025
2025
-
[38]
Effi- cient quantum state tomography.Nature communications, 1(1):149, 2010
Marcus Cramer, Martin B Plenio, Steven T Flammia, RolandoSomma, DavidGross, StephenDBartlett, Olivier Landon-Cardinal, David Poulin, and Yi-Kai Liu. Effi- cient quantum state tomography.Nature communications, 1(1):149, 2010
2010
-
[39]
Control- ling quantum many-body systems using reduced-order modeling.Physical Review Research, 6(1):013161, 2024
IA Luchnikov, MA Gavreev, and AK Fedorov. Control- ling quantum many-body systems using reduced-order modeling.Physical Review Research, 6(1):013161, 2024
2024
-
[40]
Selective and efficient estimation of parameters for quantum process tomography.Physical review letters, 100(19):190403, 2008
Ariel Bendersky, Fernando Pastawski, and Juan Pablo Paz. Selective and efficient estimation of parameters for quantum process tomography.Physical review letters, 100(19):190403, 2008
2008
-
[41]
Quantum tomography with random diagonal unitary maps and statistical bounds on information generation using random matrix theory
Sreeram PG and Vaibhav Madhok. Quantum tomography with random diagonal unitary maps and statistical bounds on information generation using random matrix theory. Physical Review A, 104(3), September 2021
2021
-
[42]
Partial standard quantum process tomography.Quantum information processing, 12(2):1379–1393, 2013
Xiaohua Wu and Ke Xu. Partial standard quantum process tomography.Quantum information processing, 12(2):1379–1393, 2013
2013
-
[43]
Demonstration of entanglement-enhanced phase estimation in solid.Nature Communications, 6(1):6726, 2015
Gang-Qin Liu, Yu-Ran Zhang, Yan-Chun Chang, Jie- Dong Yue, Heng Fan, and Xin-Yu Pan. Demonstration of entanglement-enhanced phase estimation in solid.Nature Communications, 6(1):6726, 2015
2015
-
[44]
Quantum compu- tation and quantum information.Phys
Michael A Nielsen and Isaac L Chuang. Quantum compu- tation and quantum information.Phys. Today, 54(2):60, 2001
2001
-
[45]
Chapman and hall/CRC, 2021
Domenico d’Alessandro.Introduction to quantum control and dynamics. Chapman and hall/CRC, 2021
2021
-
[46]
Cam- bridge University Press, 2014
Ryan O’Donnell.Analysis of boolean functions. Cam- bridge University Press, 2014
2014
-
[47]
Efficient quantum circuits for diag- onal unitaries without ancillas.New Journal of Physics, 16(3):033040, 2014
Jonathan Welch, Daniel Greenbaum, Sarah Mostame, and Alan Aspuru-Guzik. Efficient quantum circuits for diag- onal unitaries without ancillas.New Journal of Physics, 16(3):033040, 2014
2014
-
[48]
Cambridge University Press, Cambridge, 1999
Audrey Terras.Fourier Analysis on Finite Groups and Applications, volume 43 ofLondon Mathematical Society Student Texts. Cambridge University Press, Cambridge, 1999
1999
-
[49]
Optimizing for an arbi- trary perfect entangler
Paul Watts, Jiří Vala, Matthias M Müller, Tommaso Calarco, K Birgitta Whaley, Daniel M Reich, Michael H Goerz, and Christiane P Koch. Optimizing for an arbi- trary perfect entangler. i. functionals.Physical Review A, 91(6):062306, 2015
2015
-
[50]
Optimizing for an arbitrary perfect entangler
Michael H Goerz, Giulia Gualdi, Daniel M Reich, Chris- tiane P Koch, Felix Motzoi, K Birgitta Whaley, Jiří Vala, Matthias M Müller, Simone Montangero, and Tommaso Calarco. Optimizing for an arbitrary perfect entangler. ii. application.Physical Review A, 91(6):062307, 2015
2015
-
[51]
Characterization of two-qubit perfect entanglers.Physical Review A—Atomic, Molecular, and Optical Physics, 70(5):052313, 2004
AT Rezakhani. Characterization of two-qubit perfect entanglers.Physical Review A—Atomic, Molecular, and Optical Physics, 70(5):052313, 2004
2004
-
[52]
Romana Schirhagl, Kevin Chang, Michael Loretz, and Christian L. Degen. Nitrogen-vacancy centers in diamond: Nanoscale sensors for physics and biology.Annual Re- view of Physical Chemistry, 65(1):83–105, 2014. PMID: 24274702
2014
-
[53]
PhD thesis, Universität Stuttgart, 2012
Philipp Neumann.Towards a Room Temperature Solid State Quantum Processor – The Nitrogen-Vacancy Center in Diamond. PhD thesis, Universität Stuttgart, 2012. PhD thesis
2012
-
[54]
Optimisation of di- amond quantum processors.New Journal of Physics, 22(9):093068, sep 2020
YunHeng Chen, Sophie Stearn, Scott Vella, Andrew Horsley, and Marcus W Doherty. Optimisation of di- amond quantum processors.New Journal of Physics, 22(9):093068, sep 2020
2020
-
[55]
A ten-qubit solid-state spin register with quantum memory up to one minute.Physical Review X, 9(3):031045, 2019
Conor E Bradley, Joe Randall, Mohamed H Abobeih, Re- mon C Berrevoets, Maarten J Degen, Michiel A Bakker, Matthew Markham, Daniel J Twitchen, and Tim H Taminiau. A ten-qubit solid-state spin register with quantum memory up to one minute.Physical Review X, 9(3):031045, 2019
2019
-
[56]
Single-gate, multipartite entanglement on a room-temperature quantum register.arXiv preprint arXiv:2508.08465, 2025
Joseph D Minnella, Mathieu Ouellet, Amelia R Klein, and Lee C Bassett. Single-gate, multipartite entanglement on a room-temperature quantum register.arXiv preprint arXiv:2508.08465, 2025
2025
-
[57]
Generation of genuine all-way entanglement in defect- nuclear spin systems through dynamical decoupling se- quences.Quantum, 8:1304, 2024
Evangelia Takou, Edwin Barnes, and Sophia E Economou. Generation of genuine all-way entanglement in defect- nuclear spin systems through dynamical decoupling se- quences.Quantum, 8:1304, 2024
2024
-
[58]
Doherty, Chunhui Rita Du, and Gregory D
Marcus W. Doherty, Chunhui Rita Du, and Gregory D. Fuchs. Quantum science and technology based on color centers with accessible spin.Journal of Applied Physics, 131(1):010401, 2022
2022
-
[59]
Revealing the emergence of classicality using nitrogen-vacancy centers
Thomas K Unden, Daniel Louzon, Michael Zwolak, Wo- jciech Hubert Zurek, and Fedor Jelezko. Revealing the emergence of classicality using nitrogen-vacancy centers. 13 Physical review letters, 123(14):140402, 2019
2019
-
[60]
Krotov method for optimal control of closed quantum systems.Russian Mathematical Surveys, 74(5):851, 2019
Oleg V Morzhin and Alexander N Pechen. Krotov method for optimal control of closed quantum systems.Russian Mathematical Surveys, 74(5):851, 2019
2019
-
[61]
Henriksen
Niels E. Henriksen. Laser control of chemical reactions. Chem. Soc. Rev., 31:37–42, 2002
2002
-
[62]
Quantum speed limit for non-markovian dynamics.Physical review letters, 111(1):010402, 2013
Sebastian Deffner and Eric Lutz. Quantum speed limit for non-markovian dynamics.Physical review letters, 111(1):010402, 2013
2013
-
[63]
Quantum decay and the mandelstam-tamm-energy inequality.Journal of Physics A: Mathematical and General, 16(13):2993, 1983
Kamal Bhattacharyya. Quantum decay and the mandelstam-tamm-energy inequality.Journal of Physics A: Mathematical and General, 16(13):2993, 1983
1983
-
[64]
Quantum optimal control in a chopped basis: Appli- cations in control of bose-einstein condensates.Physical Review A, 98(2):022119, 2018
JJWH Sorensen, MO Aranburu, T Heinzel, and JF Sher- son. Quantum optimal control in a chopped basis: Appli- cations in control of bose-einstein condensates.Physical Review A, 98(2):022119, 2018
2018
-
[65]
Optimization of pulses with low bandwidth for improved excitation of multiple-quantum coherences in nmr of quadrupolar nuclei.The Journal of Chemical Physics, 152(5), 2020
Jens Jakob Sørensen, Jacob Søgaard Nyemann, Felix Mot- zoi, Jacob Sherson, and Thomas Vosegaard. Optimization of pulses with low bandwidth for improved excitation of multiple-quantum coherences in nmr of quadrupolar nuclei.The Journal of Chemical Physics, 152(5), 2020
2020
-
[66]
Distributed entanglement.Physical Review A, 61(5):052306, 2000
Valerie Coffman, Joydip Kundu, and William K Woot- ters. Distributed entanglement.Physical Review A, 61(5):052306, 2000
2000
-
[67]
Three qubits can be entangled in two inequivalent ways.Physical Review A, 62(6):062314, 2000
Wolfgang Dür, Guifre Vidal, and J Ignacio Cirac. Three qubits can be entangled in two inequivalent ways.Physical Review A, 62(6):062314, 2000
2000
-
[68]
Observation of measurement-induced en- tanglement and quantum trajectories of remote supercon- ducting qubits.Physical review letters, 112(17):170501, 2014
Nicolas Roch, Mollie E Schwartz, Felix Motzoi, Christo- pherMacklin, RajamaniVijay, AndrewWEddins, Alexan- der N Korotkov, K Birgitta Whaley, Mohan Sarovar, and Irfan Siddiqi. Observation of measurement-induced en- tanglement and quantum trajectories of remote supercon- ductin...
2014
-
[69]
Ultralong spin coherence time in isotopically engineered diamond.Nature materials, 8(5):383–387, 2009
Gopalakrishnan Balasubramanian, Philipp Neumann, Daniel Twitchen, Matthew Markham, Roman Kolesov, Norikazu Mizuochi, Junichi Isoya, Jocelyn Achard, Jo- hannes Beck, Julia Tissler, et al. Ultralong spin coherence time in isotopically engineered diamond.Nature materials, 8(5):38...
2009
-
[70]
Room-temperaturequantumbit memory exceeding one second.Science, 336(6086):1283– 1286, 2012
Peter Christian Maurer, Georg Kucsko, Christian Latta, Liang Jiang, Norman Ying Yao, Steven D Bennett, Fer- nando Pastawski, David Hunger, Nicholas Chisholm, MatthewMarkham, etal. Room-temperaturequantumbit memory exceeding one second.Science, 336(6086):1283– 1286, 2012
2012
-
[71]
California Institute of Technology, 1997
Daniel Gottesman.Stabilizer codes and quantum error correction. California Institute of Technology, 1997
1997
-
[72]
Surface codes: Towards practi- cal large-scale quantum computation.Physical Review A—Atomic, Molecular, and Optical Physics, 86(3):032324, 2012
Austin G Fowler, Matteo Mariantoni, John M Martinis, and Andrew N Cleland. Surface codes: Towards practi- cal large-scale quantum computation.Physical Review A—Atomic, Molecular, and Optical Physics, 86(3):032324, 2012
2012
-
[73]
A game of surface codes: Large-scale quantum computing with lattice surgery.Quantum, 3:128, 2019
Daniel Litinski. A game of surface codes: Large-scale quantum computing with lattice surgery.Quantum, 3:128, 2019
2019
-
[74]
Improved electron- nuclear quantum gates for spin sensing and control.PRX Quantum, 6(2):020309, 2025
HB Van Ommen, GL Van De Stolpe, N Demetriou, HKC Beukers, Jiwon Yun, TRJ Fortuin, M Iuliano, AR-P Mont- blanch, R Hanson, and TH Taminiau. Improved electron- nuclear quantum gates for spin sensing and control.PRX Quantum, 6(2):020309, 2025
2025
-
[75]
Universal control and error correction in multi-qubit spin registers in diamond.Nature nanotechnology, 9(3):171–176, 2014
Tim Hugo Taminiau, Julia Cramer, Toeno van der Sar, Viatcheslav V Dobrovitski, and Ronald Hanson. Universal control and error correction in multi-qubit spin registers in diamond.Nature nanotechnology, 9(3):171–176, 2014
2014
-
[76]
Quantum optimization with arbitrary connectivity using rydberg atom arrays.PRX Quantum, 4(1):010316, 2023
Minh-Thi Nguyen, Jin-Guo Liu, Jonathan Wurtz, Mikhail D Lukin, Sheng-Tao Wang, and Hannes Pich- ler. Quantum optimization with arbitrary connectivity using rydberg atom arrays.PRX Quantum, 4(1):010316, 2023
2023
-
[78]
Controlling quantum many-body dynamics in driven rydberg atom arrays.Science, 371(6536):1355–1359, 2021
Dolev Bluvstein, Ahmed Omran, Harry Levine, Alexander Keesling, Giulia Semeghini, Sepehr Ebadi, Tout T Wang, Alexios A Michailidis, Nishad Maskara, Wen Wei Ho, et al. Controlling quantum many-body dynamics in driven rydberg atom arrays.Science, 371(6536):1355–1359, 2021
2021
-
[79]
Hardware- efficient, fault-tolerant quantum computation with ryd- berg atoms.Physical Review X, 12(2):021049, 2022
Iris Cong, Harry Levine, Alexander Keesling, Dolev Blu- vstein, Sheng-Tao Wang, and Mikhail D Lukin. Hardware- efficient, fault-tolerant quantum computation with ryd- berg atoms.Physical Review X, 12(2):021049, 2022
2022
-
[80]
Towards scalable multi-qubit optimal control via interaction decomposition in the diago- nal frame.https://doi.org/10.5281/zenodo.18714747,
Bora Baran. Towards scalable multi-qubit optimal control via interaction decomposition in the diago- nal frame.https://doi.org/10.5281/zenodo.18714747,
-
[82]
Oxford university press, 2001
Arthur Schweiger and Gunnar Jeschke.Principles of pulse electron paramagnetic resonance. Oxford university press, 2001
2001
-
[83]
A P Nizovtsev, S Ya Kilin, A L Pushkarchuk, V A Pushkarchuk, and F Jelezko. Theoretical study of hy- perfine interactions and optically detected magnetic reso- nance spectra by simulation of the c291[nv]-h172 diamond cluster hosting nitrogen-vacancy center.New Journal of Physi...
2014
-
[84]
13C2 (I= 1 2) γ/2π(MHz/T) 3.077 10.71 10.71 Azz (MHz)−2.142.281−1.011 A⊥ (MHz) 0.00 0.240 0.014 Q(MHz)−5.010.00 0.00 Accordingly, under the RWA the nuclear sector becomes H (R W A) 0 (t)≈ X i (γiB0θi) I ′iycos(γ iB0t) +I ′ixsin(γ iB0t) ≈0 H (R W A) −1 ≈ − X i (ωi −γ iB0)I ′ iz...
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[2026]
Software
Zenodo, Version v1.0.2. Software
Reviewed August 2, 2026 · model on record in the stance chip above.
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