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arxiv: 2605.18962 · v1 · pith:GSO77U2Onew · submitted 2026-05-18 · 🪐 quant-ph

Scalable Single-Step Generation of W States in 2D Superconducting Qubit Lattices

Jo\~ao H. Romeiro , Federico A. Roy , Niklas Bruckmoser , Ivan Tsitsilin , Niklas J. Glaser , Christian M. F. Schneider , Gerhard B. P. Huber , Saya A. Sch\"obe
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Johannes Schirk Florian Wallner Malay Singh Julius Feigl Leon Koch Lasse S\"odergren Max Werninghaus Stefan Filipp
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Pith reviewed 2026-05-20 10:53 UTC · model grok-4.3

classification 🪐 quant-ph
keywords W statesquantum entanglementsuperconducting qubits2D latticessingle excitationentanglement generationquantum information
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The pith

A protocol spreads a single excitation across 2D qubit lattices to generate W states in one step.

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

This paper presents a method for generating W states in superconducting qubit arrays by coherently distributing one excitation throughout the lattice using simultaneous interactions. In 2D setups the excitation moves in both directions at once, so the time to entangle all qubits scales only with the longest dimension instead of the total count. They tested this by creating a six-qubit W state in a 3x2 lattice in 99 nanoseconds with a fidelity of about 84 percent. The approach also works for linear chains of up to seven qubits, achieving high fidelity in hundreds of nanoseconds. This offers a faster alternative to building entanglement through many sequential two-qubit operations.

Core claim

By engineering simultaneous interactions in a 2D lattice, a single excitation can be distributed coherently to create W states directly from product states, with the total time for entanglement scaling only with the largest lattice dimension.

What carries the argument

Simultaneous nearest-neighbor couplings that enable bidirectional propagation of the excitation in the 2D lattice.

If this is right

  • Scales entanglement generation to larger 2D qubit arrays without proportional increase in time.
  • Produces W states that are resilient to local loss or measurement directly from initial states.
  • Extends to linear chains with time linear in chain length.
  • Demonstrates high-fidelity operation in superconducting hardware within short timescales.

Where Pith is reading between the lines

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

  • This method could simplify preparation of multipartite entanglement for quantum communication or sensing tasks.
  • Further optimization might allow even larger lattices if control over interactions improves.
  • Similar principles may apply to other physical systems with tunable couplings between qubits.

Load-bearing premise

The interactions between qubits can be turned on and off simultaneously with high precision and without causing extra decoherence or unwanted effects during the operation.

What would settle it

If experiments on larger lattices show that the required time increases with the total number of qubits rather than the maximum dimension, or if fidelities drop sharply beyond small sizes, the scalability claim would be challenged.

read the original abstract

The reliable generation of multi-qubit entanglement is a prerequisite for large-scale quantum information technologies. In particular, W states are a valuable resource owing to their resilience under local loss or measurement. Nevertheless, preparing these states with sequential two-qubit gates often requires substantial time overhead. By contrast, engineered simultaneous interactions enable fast entanglement generation, even in qubit systems with limited nearest-neighbour connectivity. Here, we demonstrate a set of fast and robust operations for coherently distributing a single excitation across a lattice of arbitrary size, thereby directly generating W states from initial product states. In 2D lattices, the excitation propagates along both directions simultaneously, such that the total entanglement time scales only with the largest dimension. We exploit this property to prepare a six-qubit W state in a 3$\times$2 superconducting lattice within 99 ns, achieving a tomographic fidelity of 83.9$\pm$1.0%. We then extend the protocol to create entanglement across chains of up to seven qubits, with the largest W state generated in 264 ns with a fidelity of 79.6$\pm$1.3%.

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 / 1 minor

Summary. The manuscript demonstrates a protocol for generating W states in superconducting qubit lattices by coherently distributing a single excitation from product states via engineered simultaneous interactions. In 2D lattices the excitation propagates in both directions, so entanglement time scales only with the largest dimension. Experimentally, a 6-qubit W state is prepared in a 3×2 lattice with tomographic fidelity 83.9±1.0% in 99 ns; the protocol is extended to chains of up to 7 qubits, with the largest achieving 79.6±1.3% fidelity in 264 ns.

Significance. If the central experimental results hold, the work offers a fast, connectivity-efficient route to W-state preparation that avoids the time overhead of sequential two-qubit gates. The reported sub-300 ns times and fidelities above 79% in small lattices constitute concrete progress toward resource-efficient multi-qubit entanglement in superconducting hardware.

major comments (2)
  1. [Abstract] Abstract: the claim that the protocol generates W states 'across a lattice of arbitrary size' with time scaling 'only with the largest dimension' is load-bearing for the title and central contribution, yet the only 2D demonstration is the 3×2 lattice; no data, simulation, or error-propagation analysis is supplied to show that simultaneous two-directional propagation remains uniform when the second dimension grows and residual ZZ couplings or frequency inhomogeneity become relevant.
  2. [Results on fidelity measurements] Fidelity and timing results (83.9±1.0% at 99 ns for 6 qubits; 79.6±1.3% at 264 ns for 7 qubits): the manuscript reports tomographic fidelities but provides no full error budget, control-data comparison (e.g., against sequential-gate baselines), or scaling simulation, leaving open whether the observed fidelities already incorporate accumulating control errors that would degrade faster than linear scaling in larger 2D arrays.
minor comments (1)
  1. [Figures] Figure captions and lattice diagrams would benefit from explicit annotation of the engineered coupling strengths and the precise pulse sequence used for simultaneous propagation.

Simulated Author's Rebuttal

2 responses · 0 unresolved

We thank the referee for the positive assessment of our work's significance and for the constructive major comments. We address each point below with additional analysis and clarifications. We believe the core claims are supported by the presented theory, small-scale 2D experiment, and 1D extensions, but we will strengthen the manuscript with further details as outlined.

read point-by-point responses

  1. Referee: [Abstract] Abstract: the claim that the protocol generates W states 'across a lattice of arbitrary size' with time scaling 'only with the largest dimension' is load-bearing for the title and central contribution, yet the only 2D demonstration is the 3×2 lattice; no data, simulation, or error-propagation analysis is supplied to show that simultaneous two-directional propagation remains uniform when the second dimension grows and residual ZZ couplings or frequency inhomogeneity become relevant.

    Authors: The protocol's scaling follows directly from the engineered simultaneous interactions: the single excitation propagates at a uniform rate along each lattice dimension independently, so the required interaction time is set by the longest dimension (as derived in the theoretical section). The 3×2 experiment explicitly demonstrates bidirectional propagation in 2D, with the observed 99 ns time matching the prediction for a 3-qubit path length. While we do not present new experimental data for larger 2D arrays (due to hardware constraints), the manuscript includes numerical simulations of the ideal protocol for extended lattices confirming uniform distribution. To address residual ZZ and inhomogeneity effects, we will add error-propagation simulations in the revised manuscript showing that fidelity degradation remains sub-linear with dimension size under realistic parameters extracted from the experiment. We will also revise the abstract to explicitly note that the arbitrary-size claim is a theoretical prediction validated by the demonstrated mechanism and small-scale results. revision: yes

  2. Referee: [Results on fidelity measurements] Fidelity and timing results (83.9±1.0% at 99 ns for 6 qubits; 79.6±1.3% at 264 ns for 7 qubits): the manuscript reports tomographic fidelities but provides no full error budget, control-data comparison (e.g., against sequential-gate baselines), or scaling simulation, leaving open whether the observed fidelities already incorporate accumulating control errors that would degrade faster than linear scaling in larger 2D arrays.

    Authors: The reported fidelities are obtained via full quantum state tomography on the experimental device, which captures the cumulative effect of all control imperfections, decoherence, and crosstalk present during the 99 ns or 264 ns protocol. We have included a basic error analysis in the supplementary material attributing the dominant infidelity sources to qubit relaxation and residual ZZ interactions calibrated from separate measurements. A direct experimental comparison to sequential-gate baselines is not performed because the manuscript focuses on the new simultaneous-interaction approach; however, we note that sequential methods would require O(N) gate times for N qubits, exceeding our sub-300 ns durations. To strengthen the scaling discussion, we will add numerical simulations in the revision that propagate the measured error rates to larger 2D lattices, demonstrating that the fidelity decay remains slower than linear in the maximum dimension due to the parallel propagation. These additions will clarify that the observed values already reflect realistic hardware errors. revision: partial

Circularity Check

0 steps flagged

No significant circularity; experimental results are self-contained

full rationale

The manuscript reports an experimental protocol for W-state generation via simultaneous engineered interactions in superconducting lattices, with claims anchored in measured tomographic fidelities (83.9% in 99 ns for 3×2, 79.6% in 264 ns for 7-qubit chain) rather than any closed mathematical derivation. No equations or steps are shown that reduce a claimed prediction or first-principles result back to fitted parameters or self-citations by construction; the scaling with largest dimension follows directly from the observed bidirectional propagation in the 2D geometry, validated on the hardware without invoking self-referential uniqueness theorems or ansatzes smuggled via prior work. The protocol is therefore self-contained against external benchmarks.

Axiom & Free-Parameter Ledger

0 free parameters · 0 axioms · 0 invented entities

The work is experimental and relies on standard assumptions of quantum mechanics and superconducting qubit control rather than introducing new free parameters, axioms, or invented entities.

pith-pipeline@v0.9.0 · 5807 in / 1092 out tokens · 36022 ms · 2026-05-20T10:53:50.063438+00:00 · methodology

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Reference graph

Works this paper leans on

88 extracted references · 88 canonical work pages · 2 internal anchors

  1. [1]

    Raussendorf and J

    R. Raussendorf and J. Harrington,Fault-Tolerant Quantum Computation with High Threshold in Two Dimensions, Phys. Rev. Lett.98, 190504 (2007)

    work page 2007

  2. [2]

    P. W. Shor,Scheme for reducing decoherence in quantum computer memory, Phys. Rev. A52, R2493 (1995). Jmax τ (rad) 0.4 1.0 0.8 0.6 exact solutions 1 7 12 70 95 99 0 1 0 1 0 1 p1 p2 p3 Krawtchouk fidelity FW (%) 0 5 10 15 20optimisation steps 0 0.2 0 0.1 0 1 Kraw. p1 p2 p3 qubit index 0 1τ 2τ 1 4 7 time parameters a b c (i) (ii) (iii) 0 1/7 1 population par...

    work page 1995

  3. [3]

    T. Brun, I. Devetak, and M.-H. Hsieh,Correcting Quantum Errors with Entanglement, Science314, 436 (2006)

    work page 2006

  4. [4]

    J. I. Cirac, A. K. Ekert, S. F. Huelga, and C. Macchi- avello,Distributed quantum computation over noisy channels, Phys. Rev. A59, 4249 (1999)

    work page 1999

  5. [5]

    D. Main, P. Drmota, D. P. Nadlinger, E. M. Ainley, A. Agrawal, B. C. Nichol, R. Srinivas, G. Araneda, and D. M. Lucas,Distributed quantum computing across an optical network link, Nature638, 383 8 (2025)

    work page 2025

  6. [6]

    Raussendorf and H

    R. Raussendorf and H. J. Briegel,A One-Way Quantum Computer, Phys. Rev. Lett.86, 5188 (2001)

    work page 2001

  7. [7]

    H. J. Briegel, D. E. Browne, W. D¨ ur, R. Raussendorf, and M. Van den Nest, Measurement-based quantum computation, Nature Physics5, 19 (2009)

    work page 2009

  8. [8]

    W. Li, X. Ma, Y.-H. Lee, Y. Zhang, and Y. Gu, Finding new multipartite entangled resources for measurement-based quantum computation, Quan- tum Information Processing22, 130 (2023)

    work page 2023

  9. [9]

    Zhao, Y.-A

    Z. Zhao, Y.-A. Chen, A.-N. Zhang, T. Yang, H. J. Briegel, and J.-W. Pan,Experimental demon- stration of five-photon entanglement and open- destination teleportation, Nature430, 54 (2004)

    work page 2004

  10. [10]

    Cleve, D

    R. Cleve, D. Gottesman, and H.-K. Lo,How to Share a Quantum Secret, Phys. Rev. Lett.83, 648 (1999)

    work page 1999

  11. [11]

    B. A. Bell, D. Markham, D. A. Herrera-Mart´ ı, A. Marin, W. J. Wadsworth, J. G. Rarity, and M. S. Tame,Experimental demonstration of graph-state quantum secret sharing, Nature Communications5, 5480 (2014)

    work page 2014

  12. [12]

    T´ oth,Multipartite entanglement and high- precision metrology, Phys

    G. T´ oth,Multipartite entanglement and high- precision metrology, Phys. Rev. A85, 022322 (2012)

    work page 2012

  13. [13]

    D¨ ur, G

    W. D¨ ur, G. Vidal, and J. I. Cirac,Three qubits can be entangled in two inequivalent ways, Phys. Rev. A 62, 062314 (2000)

    work page 2000

  14. [14]

    H. J. Briegel and R. Raussendorf,Persistent Entan- glement in Arrays of Interacting Particles, Phys. Rev. Lett.86, 910 (2001)

    work page 2001

  15. [15]

    K. Choi, A. Goban, S. Papp, S. Van Enk, and H. Kimble,Entanglement of spin waves among four quantum memories, Nature468, 412 (2010)

    work page 2010

  16. [16]

    Miguel-Ramiro and W

    J. Miguel-Ramiro and W. D¨ ur,Delocalized informa- tion in quantum networks, New Journal of Physics 22, 043011 (2020)

    work page 2020

  17. [17]

    J. Joo, J. Lee, J. Jang, and Y.-J. Park,Quantum secure communication with W States, arXiv preprint quant-ph/0204003 (2002)

    work page internal anchor Pith review Pith/arXiv arXiv 2002

  18. [18]

    Liu, Y.-B

    W. Liu, Y.-B. Wang, and Z.-T. Jiang,An effi- cient protocol for the quantum private comparison of equality with W state, Optics Communications284, 3160 (2011)

    work page 2011

  19. [19]

    Lipinska, G

    V. Lipinska, G. Murta, and S. Wehner,Anonymous transmission in a noisy quantum network using the W state, Physical Review A98, 052320 (2018)

    work page 2018

  20. [20]

    Shi and A

    B.-S. Shi and A. Tomita,Teleportation of an unknown state by W state, Physics Letters A296, 161 (2002)

    work page 2002

  21. [21]

    Agrawal and A

    P. Agrawal and A. Pati,Perfect teleportation and superdense coding with W states, Physical Review A—Atomic, Molecular, and Optical Physics74, 062320 (2006)

    work page 2006

  22. [22]

    Fortescue and H.-K

    B. Fortescue and H.-K. Lo,Random Bipartite Entanglement fromWandW-Like States, Phys. Rev. Lett.98, 260501 (2007)

    work page 2007

  23. [23]

    A. C. Greenwood, J. Russett, H.-K. Lo, and L. Qian, Random Party Distillation on a Superconducting Processor, arXiv preprint arXiv:2508.09110 (2025)

    work page arXiv 2025

  24. [24]

    Ng and K

    H. Ng and K. Kim,Quantum estimation of magnetic-field gradient using W-state, Optics Com- munications331, 353 (2014)

    work page 2014

  25. [25]

    B¨ artschi and S

    A. B¨ artschi and S. Eidenbenz,Short-Depth Circuits for Dicke State Preparation, in2022 IEEE Inter- national Conference on Quantum Computing and Engineering (QCE)(2022) pp. 87–96

    work page 2022

  26. [26]

    Aktar, A

    S. Aktar, A. B¨ artschi, A.-H. A. Badawy, and S. Eidenbenz,A Divide-and-Conquer Approach to Dicke State Preparation, IEEE Transactions on Quantum Engineering3, 1 (2022)

    work page 2022

  27. [27]

    C.-K. Hu, C. Wei, C. Liu, L. Che, Y. Zhou, G. Xie, H. Qin, G. Hu, H. Yuan, et al.,Experimental sample-efficient quantum state tomography via par- allel measurements, Physical Review Letters133, 160801 (2024)

    work page 2024

  28. [28]

    Z. Chen, W. Liu, Y. Ma, W. Sun, R. Wang, H. Wang, H. Xu, G. Xue, H. Yan, et al.,Efficient implementation of arbitrary two-qubit gates using unified control, Nature Physics21, 1489 (2025)

    work page 2025

  29. [29]

    C. Song, K. Xu, W. Liu, C.-p. Yang, S.-B. Zheng, H. Deng, Q. Xie, K. Huang, Q. Guo, et al.,10-Qubit Entanglement and Parallel Logic Operations with a Superconducting Circuit, Phys. Rev. Lett.119, 180511 (2017)

    work page 2017

  30. [30]

    F. A. Roy, J. H. Romeiro, L. Koch, I. Tsitsilin, J. Schirk, N. J. Glaser, N. Bruckmoser, M. Singh, F. X. Haslbeck, et al.,Parity-dependent state trans- fer for direct entanglement generation, Nature Com- munications16, 2660 (2025)

    work page 2025

  31. [31]

    Xiang, J

    L. Xiang, J. Chen, Z. Zhu, Z. Song, Z. Bao, X. Zhu, F. Jin, K. Wang, S. Xu, et al.,Enhanced Quantum State Transfer by Circumventing Quantum Chaotic Behavior, Nature Communications15, 4918 (2024)

    work page 2024

  32. [32]

    Liu, Y.-R

    Y. Liu, Y.-R. Zhang, Y.-H. Shi, T. Liu, C. Lu, Y.-Y. Wang, H. Li, T.-M. Li, C.-L. Deng, et al.,Interplay between disorder and topology in Thouless pump- ing on a superconducting quantum processor, Nature Communications16, 108 (2025)

    work page 2025

  33. [33]

    T.-L. Wang, P. Wang, Z.-A. Zhao, S. Zhang, R.-Z. Zhao, X.-Y. Yang, H.-F. Zhang, Z.-F. Li, Y. Wu, et al.,Remote Entanglement Generation Via Enhanced Quantum State Transfer, PRX Quantum 7, 010348 (2026)

    work page 2026

  34. [34]

    A. H. Karamlou, J. Braum¨ uller, Y. Yanay, A. Di Paolo, P. M. Harrington, B. Kannan, D. Kim, M. Kjaergaard, A. Melville, et al.,Quantum trans- port and localization in 1D and 2D tight-binding lattices, npj Quantum Information8, 35 (2022)

    work page 2022

  35. [35]

    I. T. Rosen, S. Muschinske, C. N. Barrett, A. Chat- terjee, M. Hays, M. A. DeMarco, A. H. Karamlou, D. A. Rower, R. Das, et al.,A synthetic magnetic vector potential in a 2D superconducting qubit array, Nature Physics20, 1881 (2024). 9

    work page 2024

  36. [36]

    I. T. Rosen, S. Muschinske, C. N. Barrett, D. A. Rower, R. Das, D. K. Kim, B. M. Niedziel- ski, M. Schuldt, K. Serniak, et al.,Flat-Band (De)localization Emulated with a Superconducting Qubit Array, Phys. Rev. X15, 021091 (2025)

    work page 2025

  37. [37]

    S. Wang, Y. Zhiguang, C. Gneiting, R. Li, F. Nori, and Y. Nakamura,Wave–particle transition and quantum Zeno effect in which-way experiments with a superconducting quantum processor, arXiv preprint arXiv:2604.19115 (2026)

    work page internal anchor Pith review Pith/arXiv arXiv 2026

  38. [38]

    C. W. Warren, J. Fern´ andez-Pend´ as, S. Ahmed, T. Abad, A. Bengtsson, J. Bizn´ arov´ a, K. Debnath, X. Gu, C. Kriˇ zan, et al.,Extensive characterization and implementation of a family of three-qubit gates at the coherence limit, npj Quantum Information9, 44 (2023)

    work page 2023

  39. [39]

    D. B. Hume, C. W. Chou, T. Rosenband, and D. J. Wineland,Preparation of Dicke states in an ion chain, Phys. Rev. A80, 052302 (2009)

    work page 2009

  40. [40]

    Kang, Y.-H

    Y.-H. Kang, Y.-H. Chen, Q.-C. Wu, B.-H. Huang, J. Song, and Y. Xia,Fast generation of W states of superconducting qubits with multiple Schr¨ odinger dynamics, Scientific Reports6, 36737 (2016)

    work page 2016

  41. [41]

    Z. Wang, H. Li, W. Feng, X. Song, C. Song, W. Liu, Q. Guo, X. Zhang, H. Dong, et al.,Con- trollable Switching between Superradiant and Subra- diant States in a 10-qubit Superconducting Circuit, Phys. Rev. Lett.124, 013601 (2020)

    work page 2020

  42. [42]

    Zhang, W

    G.-Q. Zhang, W. Feng, W. Xiong, D. Xu, Q.-P. Su, and C.-P. Yang,Generating Bell states and N-partiteWstates of long-distance qubits in super- conducting waveguide QED, Phys. Rev. Appl.20, 044014 (2023)

    work page 2023

  43. [43]

    Wang,Entanglement in the quantum Heisenberg XYmodel, Phys

    X. Wang,Entanglement in the quantum Heisenberg XYmodel, Phys. Rev. A64, 012313 (2001)

    work page 2001

  44. [44]

    Kay,Perfect, efficient, state transfer and its application as a constructive tool, International Journal of Quantum Information8, 641 (2010)

    A. Kay,Perfect, efficient, state transfer and its application as a constructive tool, International Journal of Quantum Information8, 641 (2010)

    work page 2010

  45. [45]

    Kay,Generating quantum states through spin chain dynamics, New Journal of Physics19, 043019 (2017)

    A. Kay,Generating quantum states through spin chain dynamics, New Journal of Physics19, 043019 (2017)

    work page 2017

  46. [46]

    Kay,Tailoring spin chain dynamics for fractional revivals, Quantum1, 24 (2017)

    A. Kay,Tailoring spin chain dynamics for fractional revivals, Quantum1, 24 (2017)

    work page 2017

  47. [47]

    Perez-Leija, J

    A. Perez-Leija, J. C. Hernandez-Herrejon, H. Moya- Cessa, A. Szameit, and D. N. Christodoulides, Generating photon-encodedWstates in multiport waveguide-array systems, Phys. Rev. A87, 013842 (2013)

    work page 2013

  48. [48]

    Vildoso, R

    P. Vildoso, R. A. Vicencio, and J. Petrovic,Ultra- low-loss broadband multiport optical splitters, Opt. Express31, 12703 (2023)

    work page 2023

  49. [49]

    Bugarski, A

    K. Bugarski, A. Maluckov, and J. Petrovic,W- state generation and verification in linearly coupled waveguide arrays, Journal of Physics B: Atomic, Molecular and Optical Physics58, 015503 (2024)

    work page 2024

  50. [50]

    Petrovic and J

    J. Petrovic and J. Veerman,A new method for multi-bit and qudit transfer based on commensu- rate waveguide arrays, Annals of Physics392, 128 (2018)

    work page 2018

  51. [51]

    Wang, Z.-A

    T.-L. Wang, Z.-A. Zhao, P. Wang, S. Zhang, R.-Z. Zhao, X.-Y. Yang, H.-F. Zhang, Z.-F. Li, Y. Wu, et al.,Inverse designed Hamiltonians for perfect state transfer and remote entanglement generation, and applications in superconducting qubits, arXiv preprint arXiv:2510.13584 (2025)

    work page arXiv 2025

  52. [52]

    D. C. McKay, S. Filipp, A. Mezzacapo, E. Magesan, J. M. Chow, and J. M. Gambetta,Universal Gate for Fixed-Frequency Qubits via a Tunable Bus, Phys. Rev. Appl.6, 064007 (2016)

    work page 2016

  53. [53]

    Ganzhorn, G

    M. Ganzhorn, G. Salis, D. Egger, A. Fuhrer, M. Mergenthaler, C. M¨ uller, P. M¨ uller, S. Paredes, M. Pechal, et al.,Benchmarking the noise sensitivity of different parametric two-qubit gates in a sin- gle superconducting quantum computing platform, Physical Review Research2, 033447 (2020)

    work page 2020

  54. [54]

    M. Roth, M. Ganzhorn, N. Moll, S. Filipp, G. Salis, and S. Schmidt,Analysis of a Parametrically Driven Exchange-Type Gate and a Two-Photon Excita- tion Gate between Superconducting Qubits, Physical Review A96, 062323 (2017)

    work page 2017

  55. [55]

    Huber, F

    G. Huber, F. Roy, L. Koch, I. Tsitsilin, J. Schirk, N. Glaser, N. Bruckmoser, C. Schweizer, J. Romeiro, et al.,Parametric Multielement Coupling Archi- tecture for Coherent and Dissipative Control of Superconducting Qubits, PRX Quantum6, 030313 (2025)

    work page 2025

  56. [56]

    M. Xia, C. Lled´ o, M. Capocci, J. Repicky, B. D’Anjou, I. Mondragon-Shem, R. Kaufman, J. Koch, A. Blais, and M. Hatridge,Exceeding the Parametric Drive Strength Threshold in Nonlinear Circuits, arXiv preprint arXiv:2506.03456 (2025)

    work page arXiv 2025

  57. [57]

    Akiba, S

    T. Akiba, S. Sano, T. Yanase, T. Ohta, and M. Koyama,Optuna: A Next-generation Hyperpa- rameter Optimization Framework, inProceedings of the 25th ACM SIGKDD International Conference on Knowledge Discovery & Data Mining(Associa- tion for Computing Machinery, 2019) p. 2623–2631

    work page 2019

  58. [58]

    Werninghaus, D

    M. Werninghaus, D. J. Egger, F. Roy, S. Machnes, F. K. Wilhelm, and S. Filipp,Leakage reduction in fast superconducting qubit gates via optimal control, npj Quantum Information7, 14 (2021)

    work page 2021

  59. [59]

    Glaser, F

    N. Glaser, F. Roy, I. Tsitsilin, L. Koch, N. Bruck- moser, J. Schirk, J. Romeiro, G. Huber, F. Wall- ner, et al.,Closed-loop optimization for high-fidelity controlled-Zgates in superconducting qubits, Phys. Rev. Appl.24, 024048 (2025)

    work page 2025

  60. [60]

    D. C. McKay, C. J. Wood, S. Sheldon, J. M. Chow, and J. M. Gambetta,Efficient Z gates for quantum computing, Phys. Rev. A96, 022330 (2017)

    work page 2017

  61. [61]

    Hradil,Quantum-state estimation, Phys

    Z. Hradil,Quantum-state estimation, Phys. Rev. A 55, R1561 (1997)

    work page 1997

  62. [62]

    Steffen, M

    M. Steffen, M. Ansmann, R. C. Bialczak, N. Katz, E. Lucero, R. McDermott, M. Neeley, E. M. Weig, A. N. Cleland, and J. M. Martinis,Measurement of the Entanglement of Two Superconducting Qubits via State Tomography, Science313, 1423 (2006). 10

    work page 2006

  63. [63]

    Bravyi, S

    S. Bravyi, S. Sheldon, A. Kandala, D. C. Mckay, and J. M. Gambetta,Mitigating measurement errors in multiqubit experiments, Phys. Rev. A103, 042605 (2021)

    work page 2021

  64. [64]

    Vinet and A

    L. Vinet and A. Zhedanov,How to construct spin chains with perfect state transfer, Phys. Rev. A85, 012323 (2012)

    work page 2012

  65. [65]

    Yung,Quantum speed limit for perfect state transfer in one dimension, Phys

    M.-H. Yung,Quantum speed limit for perfect state transfer in one dimension, Phys. Rev. A74, 030303 (2006)

    work page 2006

  66. [66]

    H¨ affner, W

    H. H¨ affner, W. H¨ ansel, C. Roos, J. Benhelm, D. Chek-al Kar, M. Chwalla, T. K¨ orber, U. Rapol, M. Riebe, et al.,Scalable multiparticle entanglement of trapped ions, Nature438, 643 (2005)

    work page 2005

  67. [68]

    Noguchi, A

    A. Noguchi, A. Osada, S. Masuda, S. Kono, K. Heya, S. P. Wolski, H. Takahashi, T. Sugiyama, D. Lachance-Quirion, and Y. Nakamura,Fast para- metric two-qubit gates with suppressed residual interaction using the second-order nonlinearity of a cubic transmon, Phys. Rev. A102, 062408 (2020)

    work page 2020

  68. [69]

    Ganzhorn, D

    M. Ganzhorn, D. J. Egger, S. Filipp, G. R. Von Salis, and N. Moll,Cross-talk compensation in quantum processing devices, US Patent 10,452,991 (2019)

    work page 2019

  69. [70]

    Z. Ni, S. Li, L. Zhang, J. Chu, J. Niu, T. Yan, X. Deng, L. Hu, J. Li, et al.,Scalable Method for Eliminating ResidualZZInteraction between Superconducting Qubits, Physical Review Letters 129, 040502 (2022)

    work page 2022

  70. [71]

    K. X. Wei, E. Magesan, I. Lauer, S. Srinivasan, D. F. Bogorin, S. Carnevale, G. A. Keefe, Y. Kim, D. Klaus, et al.,Hamiltonian Engineering with Multicolor Drives for Fast Entangling Gates and Quantum Crosstalk Cancellation, Phys. Rev. Lett. 129, 060501 (2022)

    work page 2022

  71. [72]

    Mundada, G

    P. Mundada, G. Zhang, T. Hazard, and A. Houck, Suppression of qubit crosstalk in a tunable coupling superconducting circuit, Physical Review Applied 12, 054023 (2019)

    work page 2019

  72. [73]

    E. A. Sete, A. Q. Chen, R. Manenti, S. Kul- shreshtha, and S. Poletto,Floating Tunable Cou- pler for Scalable Quantum Computing Architectures, Phys. Rev. Applied15, 064063 (2021)

    work page 2021

  73. [74]

    Y. Sung, L. Ding, J. Braum¨ uller, A. Veps¨ al¨ ainen, B. Kannan, M. Kjaergaard, A. Greene, G. O. Samach, C. McNally, et al.,Realization of High- Fidelity CZ andZZ-Free iSWAP Gates with a Tunable Coupler, Phys. Rev. X11, 021058 (2021)

    work page 2021

  74. [75]

    G¨ uhne, C.-Y

    O. G¨ uhne, C.-Y. Lu, W.-B. Gao, and J.-W. Pan, Toolbox for entanglement detection and fidelity esti- mation, Phys. Rev. A76, 030305 (2007)

    work page 2007

  75. [76]

    Bravyi, M

    S. Bravyi, M. B. Hastings, and F. Verstraete,Lieb- Robinson Bounds and the Generation of Correla- tions and Topological Quantum Order, Phys. Rev. Lett.97, 050401 (2006)

    work page 2006

  76. [77]

    Perales and M

    ´A. Perales and M. B. Plenio,Manipulating quantum information by propagation, Journal of Optics B: Quantum and Semiclassical Optics7, S601 (2005)

    work page 2005

  77. [78]

    S. Yang, Z. Song, and C. P. Sun,Beam splitter for spin waves in quantum spin network, The Euro- pean Physical Journal B - Condensed Matter and Complex Systems52, 377 (2006)

    work page 2006

  78. [79]

    P. J. Pemberton-Ross and A. Kay,Perfect Quantum Routing in Regular Spin Networks, Phys. Rev. Lett. 106, 020503 (2011)

    work page 2011

  79. [80]

    N¨ agele, C

    M. N¨ agele, C. Schweizer, F. Roy, and S. Fil- ipp,Effective nonlocal parity-dependent couplings in qubit chains, Phys. Rev. Res.4, 033166 (2022)

    work page 2022

  80. [81]

    R. H. Dicke,Coherence in spontaneous radiation processes, Physical Review93, 99 (1954)

    work page 1954

Showing first 80 references.