Superpositioned

Appendix: Key Empirical Anchors (as of February 2026; refreshed April 2026)

Hardware Milestones

Google WillowDec 2024
  • 105 superconducting qubits.
  • First below-threshold surface code QEC.
  • Distance-7 code with 0.143% error per cycle.
  • Logical qubit lifetime 2.4× best physical qubit.
  • Error suppression factor Λ = 2.14 ± 0.02.
  • Published in Nature (doi: 10.1038/s41586-024-08449-y[4])
Quantinuum HeliosNov 2025 · upgrade Mar 2026
  • 98 trapped-ion qubits.
  • 94 error-detected logical qubits using [[4,2,2]] Iceberg code (distance-2 detection via post-selection, not active error correction).
  • 48 logical qubits at 2:1 encoding ratio via code concatenation.
  • 99.921% two-qubit gate fidelity.
  • 99.9975% single-qubit gate fidelity.
  • Real-time error detection with NVIDIA Grace Hopper GPUs.
  • $10B valuation, $800M funding round.
  • March 2026 update: 48 logical qubits under active error correction at logical gate error ~1×10-4 (below raw physical, via concatenated codes); separately, 94 error-detected logical qubits prepared in a GHZ state at 94.9% fidelity (parity-oscillation lower bound, via [[4,2,2]] post-selection). Peer review pending[9].
Microsoft Majorana 1Feb 2025
  • 8 topological qubits claimed.
  • First topoconductor.
  • Nature publication (doi: 10.1038/s41586-024-08445-2[5]).
  • Claims disputed by physicists at APS Global Physics Summit 2025 and in Nature commentary

DARPA US2QC final stage selected.

IBM NighthawkNov 2025
  • 120 qubits, 218 tunable couplers, square lattice.
  • 5,000 two-qubit gate capability
IBM LoonNov 2025
  • 112 qubits, experimental, demonstrates all hardware elements for fault-tolerant computing including c-couplers and real-time qLDPC decoding (<480ns, 10× speedup).
  • 300mm wafer fabrication
PrincetonNov 2025
  • Transmon qubit >1ms coherence time.
  • 3× previous record.
  • 15× industry standard
IonQ/AnsysMar 2025
  • Reported 12% speedup on a single medical device simulation instance[3] using 36-qubit IonQ system vs. classical HPC.
  • Result not independently replicated; classical baseline not independently verified; commercial significance of margin uncertain given quantum compute cost premium
Google Quantum EchoesOct 2025
  • Out-of-time-ordered-correlator (OTOC) algorithm on 65 of Willow's 105 qubits.
  • 13,000× faster than Frontier supercomputer on same task.
  • First verifiable quantum advantage claim (reproducible on another quantum device).
  • Companion Nature paper: 15- and 28-atom molecular structure with UC Berkeley[10].
Rigetti Cepheus-1Apr 2026
  • 108 superconducting qubits.
  • Rigetti's first 100+ qubit system live on cloud (April 7, 2026).
  • $8.4M India C-DAC order for a 108-qubit system in H2 2026[11].
Infleqtion SqaleFeb–Mar 2026
  • Neutral-atom (cesium) modality.
  • 100 operational qubits delivered to UK National Quantum Computing Centre in late 2025; publicly announced March 16, 2026.
  • Best-case 99.73% two-qubit gate fidelity (company disclosures, not single peer-reviewed experiment; comparable neutral-atom systems in 99.5–99.7% range).
  • ~2.8-second ground-state coherence time (gate-operational coherence is orders of magnitude shorter during Rydberg gates, standard across neutral-atom platforms).
  • NYSE: INFQ since Feb 17, 2026 (SPAC closed Feb 13, 2026; $1.8B transaction value; >$540M gross proceeds; ~$3.0B market cap as of April 15, 2026).
  • Not selected for DARPA QBI Stage B (Nov 2025)[12].
IonQ photonic interconnectApr 2026
  • First commercial photonic interconnect between two trapped-ion QPUs: photon generation, transmission, and detection to entangle qubits across separate systems.
  • AFRL-funded.
  • IonQ's 99.99% intra-QPU two-qubit gate fidelity is a separate 2025 result, not a networked-link figure.
  • IonQ selected April 14, 2026 for DARPA HARQ diamond-NV quantum-memory program[13].
IonQ FTQC blueprintApr 2026
  • Technical roadmap paper published April 22, 2026.
  • Targets an end-to-end path to fault-tolerant systems at 10,000+ physical qubits.
  • Useful for roadmap specificity; not an independently validated hardware milestone[17].
IBM Q4BioApr 2026
  • Wellcome Leap Q4Bio Phase III results highlighted April 16, 2026.
  • Five of six finalists used IBM quantum hardware.
  • Algorithmiq / Cleveland Clinic / IBM won $2M prize for a hybrid photodynamic-therapy simulation workflow with circuits up to ~100 qubits.
  • Application-pipeline signal, not proven practical quantum advantage[18].

Market Data

MetricData
Global QC Market~$3.5B (2025), projected $20B+ by 2030 (MarketsandMarkets[2])
McKinseyup to $97B quantum technology revenue by 2035, $72B from quantum computing
Note: these are top-down consulting estimates, not bottom-up revenue models; the $72B QC figure would exceed the current global HPC market of ~$50-60B; consulting-firm tech projections have a poor historical track record for emerging technologies
Equity Funding$3.77B first 9 months 2025 (~3× 2024 full year)
Gov. Commitments>$10B globally by April 2025
PQC Market$1.9B (2025), projected $12.4B by 2035
Public listings Q1 2026Infleqtion (NYSE: INFQ) SPAC closed Feb 13, 2026 (trading opened Feb 17); ~$3.0B market cap as of April 15, 2026; IQM / Real Asset Acquisition Corp. (Nasdaq: RAAQ) SPAC announced Feb 23, 2026 at ~$1.8B pre-money; Nasdaq listing ~June 2026; Quantinuum S-1 confidential filing Jan 14, 2026 (valuation/raise size not publicly disclosed)[14]
Infleqtion revenue$32.5M (2025), $40M guide (2026, announced Apr 8); $200M+ customer pipeline (quantum computing + sensing)[15]
Public market drawdowns Apr 2026Mizuho price-target cuts: IONQ $61 (from $80), RGTI $33 (from $43), QBTS $31 (from $40); Outperform maintained. Sector rallied Apr 14–15 on IonQ photonic interconnect + DARPA HARQ news (IONQ +18%, QBTS +15%, RGTI +12%)[16]
Quantum-safe urgencyIBM's April 17, 2026 quantum-safe brief argues that fault-tolerant machines could begin approaching cryptographic relevance by the end of the decade; treat this as vendor risk framing, but it reinforces the need to start PQC migration now[19].

Roadmap Targets

Quantinuum
Sol (192 physical qubits, 2027)
Apollo (thousands physical, hundreds logical, fault-tolerant, 2029)
IBM
Kookaburra (modular logical storage, 2026)
Cockatoo (multi-chip entanglement, 2027)
Starling (200 logical qubits, 100M gates, 2029)
roadmap through 2033
IBM 2026 milestone

Roadmap target: first examples of scientific quantum advantage using quantum + HPC, Nighthawk up to three 120-qubit modules (360 qubits) and 7,500 gates, plus Kookaburra module for logical processing and quantum memory[20].

Google

Error-corrected useful computation by end of decade; long-term million-qubit fault-tolerant target

Microsoft
Topological qubit array
million qubits on single chip (long-term);
Infleqtion
30+ logical qubits (2026)
100+ logical qubits (2028)
1,000+ logical qubits (2030)

DARPA QBI evaluation underway; HARQ program announced April 14, 2026

DARPA QBI + HARQ

11 companies in QBI Stage B across 5 modalities (Atom Computing, Diraq, IBM, IonQ, Nord Quantique, Photonic Inc., Quantinuum, Quantum Motion, QuEra, Silicon Quantum Computing, Xanadu); Infleqtion did not advance to Stage B — a data point, not a verdict, given that HARQ and DoE/NSA tracks remain open. Microsoft + PsiQuantum advanced to final stage of the related US2QC program. HARQ (announced April 14, 2026) complements QBI with heterogeneous (compute + memory) qubit architectures — 19 performer teams including IonQ (diamond-NV memory).

Figure 13: Quantum Computing Industry Roadmap: 2024–2033
Figure 13: Quantum Computing Industry Roadmap: 2024–2033
Multiple companies targeting hundreds of logical qubits by end of decade. Hatched bars represent roadmap targets.

Notes

  1. Quantinuum, 'Introducing Helios: The World’s Most Advanced Quantum Computer,' quantinuum.com (November 2025). ↩
  2. MarketsandMarkets, Quantum Computing Market Report (2025). ↩
  3. IonQ/Ansys, reported 12% speedup on medical device simulation using 36-qubit Forte Enterprise system (March 2025). ↩
  4. Acharya, R. et al., 'Quantum error correction below the surface code threshold,' Nature 638, 920–926 (2025). [link] ↩
  5. Aghaee, M. et al., 'Interferometric single-shot parity measurement in an InAs–Al hybrid device,' Nature 638, 651–655 (2025). [link] ↩
  6. McKinsey & Company, Quantum Technology Monitor 2025. ↩
  7. Bain & Company, Technology Report 2025: quantum computing market analysis. ↩
  8. APS Physics, 'Microsoft’s Claim of a Topological Qubit Faces Tough Questions,' APS Global Physics Summit (March 2025). ↩
  9. Quantinuum researchers demonstrate quantum computations with dozens of protected logical qubits, The Quantum Insider (March 10, 2026). [link] ↩
  10. Google Quantum AI, 'Quantum Echoes: the first verifiable quantum advantage on Willow,' blog.google (October 22, 2025). [link] ↩
  11. Rigetti Computing, Q4 2025 / FY 2025 results and Cepheus-1 108-qubit system launch (April 7, 2026). [link] ↩
  12. Infleqtion, 100-qubit Sqale deployment at UK NQCC (March 2026) and Churchill Capital Corp X business combination (February 2026). [link] ↩
  13. IonQ, 'Photonic interconnect milestone demonstrating networked quantum systems using entanglement' (April 14, 2026); DARPA HARQ selection. [link] ↩
  14. The Quantum Insider, 'Honeywell announces Quantinuum has filed confidential paperwork for a possible IPO' (January 14, 2026); CNBC, Finland's IQM to list via SPAC merger (February 23, 2026). [link] ↩
  15. Infleqtion, '2026 revenue guidance of $40 million,' investor relations press release (April 8, 2026). [link] ↩
  16. Mizuho Securities equity research price target revisions (April 2026); 24/7 Wall St sector rally coverage (April 14, 2026). ↩
  17. IonQ, 'IonQ Publishes Definitive Technical Report, Establishing Its Fault-Tolerant Quantum Computing Trajectory' (April 22, 2026). [link] ↩
  18. IBM, 'How IBM Quantum is Enabling Healthcare and Biology Research' (April 16, 2026). [link] ↩
  19. IBM, 'Quantum computers are speeding towards cryptographic relevancy: The time to prepare is now' (April 17, 2026). [link] ↩
  20. IBM Quantum Roadmap, 2026 strategic milestones. [link] ↩