Omega chipset (Moreton Bay / Chicago systems unnamed)
Omega chipset (Moreton Bay / Chicago systems unnamed)
Register profile — the machine's variant of its architecture
qubit type: single photon, dual-rail (path) encoded, telecom C-band 1550 nm
gate mechanism: linear-optical fusion (probabilistic Bell measurement, 50% / 75% boosted); no gates in the circuit-model sense
connectivity: set by the fusion network (any 3-D cell complex with 4 faces per edge is a valid surface-code fusion complex); physical routing by BTO switches
control: electro-optic BTO Mach-Zehnder modulators, EO coefficient ~1000 pm/V; feed-forward within one clock cycle
control placement: room-temp electro-optic
readout: waveguide-integrated SNSPD, destructive, photon-number-resolving; 93.4% median on-chip efficiency (the 98.9% figure is superseded)
gate evidence: no published figure
decoder mode: offline — syndromes decoded after the run
codes: fusion, rbh
flags: a component, not a machine, cryogenic details missing, no qec cycle
Technologies by layer — the machine's cell per layer
| 1 Qubit carrier | Single photon (discrete variable) · primary ▣ Fig. 2a,b (photon source, 99.5% purity); §Photon sources ✅ single photon, dual-rail (path) encoded, telecom C-band 1550 nm; Omega chipset demonstrated at component level Feb 2025 |
| 2 Encoding | Dual-rail (erasure) encoding · primary ▣ Fig. 3a,e (qubit SPAM circuit, Pauli eigenstates) ✅ dual-rail path encoding; loss handled as erasure (model threshold 11.98% erasure / 1.07% Pauli per fusion) Time-bin / path photonic encoding · alternate ◌ 🔎 alternate photonic dual-rail family; PsiQuantum states path encoding |
| 3 Gate mechanism | Linear-optical fusion (heralded) · primary ▣ Fig. 3d,h (two-qubit fusion); Fig. 3c,f (HOM) ✅ linear-optical fusion (probabilistic Bell measurement, 50%/75% boosted); 2-qubit fusion fidelity 99.22 ± 0.12%, HOM visibility 99.5% (Feb 2025) Multi-photon resource-state generator (RSG; 6-ring etc.) · alternate ▨ 🔎 missing half: no resource-state factory result published; source purity ~99.8% |
| 4 Connectivity / transport | Photonic switching / routing (electro-optic, feed-forward) · primary ▣ Fig. 2d (MZI >50 dB extinction); Fig. 5g (BTO MZI) ✅ set by the fusion network (3-D cell complex, 4 faces per edge); BTO-switch routing; on-chip interferometer fidelity up to 99.999%, >50 dB extinction |
| 5 Control | Electro-optic drive + feed-forward electronics (room temperature) · primary ▣ Fig. 5d–g (BTO Pockels, phase shifter); §Electro-optic switching ✅ BTO Mach-Zehnder modulators, EO coefficient ~1000 pm/V, switch loss ~10 dB/m; feed-forward within one clock cycle; room-temperature electronics |
| 6 Readout | Single-photon detection (SNSPD / TES) · primary ▣ Fig. 2e (SNSPD efficiency); Fig. 4d–f (PNRD) ✅ waveguide-integrated PNR SNSPD, destructive; 93.4% median on-chip efficiency (0.30 dB/detection); SPAM fidelity 99.98 ± 0.01% (Feb 2025) |
| 7 Code | Fusion-based fault tolerance · primary ▦ ✅ FBQC fusion code on RBH foliated cluster; model thresholds 11.98% erasure / 1.07% Pauli per fusion; no QEC cycle or logical qubit published |
| 8 Decoder | MWPM / Sparse Blossom (+ correlated matching) · primary ▦ ✅ MWPM / union-find on the fusion syndrome graph; offline |
| 9 Interconnect | Fibre links between photonic modules · primary ▣ Fig. 3b,g (chip-to-chip qubit interconnect); Fig. 5c (fibre-to-chip) ✅ standard telecom fibre, no transduction; chip-to-chip Bell fidelity 99.72(4)% over up to 250 m; edge coupler ~52(12) mdB/facet |
| 10 Manufacturing | Photonic IC foundry (SiN, BTO, TFLN, SNSPD on 300 mm) · primary ▣ Fig. 1a–j (process modules, 300-mm wafer, cross-sections); §Technology stack ✅ GlobalFoundries Fab 8 (Malta NY), 300 mm Si photonics, 45 nm node; BTO by custom 300 mm MBE; SiN loss 0.5 vs 1.8(2) dB/m unreconciled |
Standard records
crosstalk → 1.00e-5 · best (1 - interferometer fidelity 99.999%)
Feb 2025 · source
SPAM error → 2.00e-4 · best (SPAM error, 99.98 +- 0.01%)
Feb 2025 · source
device yield → 0.934 · typical (median on-chip SNSPD efficiency)
supersedes the 98.9% figure sometimes quoted · Feb 2025 · source
evidence: ✅ 10 / 12
Pictures
Every picture carries the story of what it shows and its credit line.