Postselect decoded QEC shots by matching-weight confidence. V7 temporal scorer hits 41.3% LER reduction on IBM Fez (block-stratified, 5-fold CV). Drift-stratified weight-only baseline: ~7.7%.
Calibrated to hardware validation data from IBM Heron and Rigetti Ankaa-3 (Feb 2026).
All shots accepted (no veto)
,
Total Shots
,
Logical Errors
,
Logical Error Rate (LER)
High-risk shots vetoed
,
Accepted
,
Vetoed
,
Errors
,
Logical Error Rate (LER)
SafetyGate adapts to each vendor's noise profile. Calibration windows are hours, not days, so results are reported per regime, stable sessions deliver a larger uplift, drift-stratified sessions a smaller one. Same safety guarantee in both.
Stable-regime sessions
41.3% LER reduction
IBM Torino + Rigetti Ankaa-3
Drift-stratified (IBM Fez)
7.7% LER reduction
CW matching-weight, stable blocks
Throughput retained
71-96%
Regime-dependent
Total validated
26,000+ shots
4 backends, 2 vendors
Hardware validation: IBM Heron (Torino, Fez, Marrakesh) + Rigetti Ankaa-3 (Feb-Apr 2026). Fez April 7 session showed intra-session drift (monotonic detection-rate ramp, R² = 0.992) — expected physics for superconducting qubits between calibration windows. Earlier “23.1%” CW number retired; honest drift-stratified baseline is 7.7%. See SafetyGate guide for full drift-audit methodology.
Surface codes encode logical qubits in a 2D grid of physical qubits. Error measurements detect faults, and decoders attempt to correct them. However, correlated errors can create patterns that fool the decoder.
SafetyGate analyzes error indicators to compute a risk score. Shots likely to cause errors are vetoed before they can corrupt results.
Validated on IBM Heron and Rigetti Ankaa-3 quantum processors. SafetyGate reduces logical error rate by 39-57% on real hardware, across 26,000 shots on 4 backends from 2 vendors.
39-57%
LER Reduction
26,000
Hardware Shots
2
Vendors
4
Backends
SafetyGate adapts behaviour to the current calibration regime automatically. Calibration windows drift; SafetyGate responds.
| Regime | Backend | Shots | Baseline LER | Gated LER | Action |
|---|---|---|---|---|---|
| Below threshold | Marrakesh | 2,000 | 0.00% | 0.00% | 99.9% allow |
| Near threshold | Torino | 18,000 | 0.34% | 0.21% | 39% reduction |
| Near threshold | Ankaa-3 (Rigetti) | 8,000 | 0.21% | 0.09% | 57% reduction |
| Above threshold | Torino (IBM) | 12,000 | 38-49% | n/a | 100% block |
d=3 repetition code. IBM Heron: 6 jobs, 62 doomed shots. Rigetti Ankaa-3: 1 job, 17 doomed shots.
SafetyGate vetoes 29% of shots, retaining 71% throughput. Among allowed shots, logical error rate drops 39%. Net effect: higher reliability at moderate throughput cost.
Multi-round syndrome analysis is the key differentiator. Detection accuracy degrades significantly without temporal context, confirming that single-round heuristics miss correlated failure modes.
When the backend drifts outside its published calibration window, SafetyGate blocks 100% of shots rather than returning results with understated error bars. This prevents compute waste and protects downstream applications from results they cannot defend.
100,000 Stim-simulated episodes across 4 code distances and 5 noise regimes. Wilson 95% confidence intervals. Every cell shows 88-100% LER reduction.
88-100%
LER Reduction
100,000
Episodes Validated
20
Test Configurations
<1%
Typical FAR-bad
| Distance | STABLE | AGING | STEP CHANGE | GLITCH | LEAKAGE |
|---|---|---|---|---|---|
| d=3 | 97.4% FAR: 1.4% Allow: 51% | 95.8% FAR: 1.8% Allow: 42% | 93.8% FAR: 2.4% Allow: 39% | 91.4% FAR: 4.7% Allow: 54% | 100.0% FAR: 0.0% Allow: 52% |
| d=5 | 96.7% FAR: 1.0% Allow: 31% | 97.3% FAR: 0.4% Allow: 15% | 96.0% FAR: 0.6% Allow: 14% | 95.9% FAR: 1.1% Allow: 28% | 98.4% FAR: 0.5% Allow: 28% |
| d=7 | 96.6% FAR: 0.7% Allow: 19% | 99.0% FAR: 0.1% Allow: 6% | 95.8% FAR: 0.2% Allow: 5% | 96.1% FAR: 0.6% Allow: 16% | 94.8% FAR: 0.9% Allow: 17% |
| d=9 | 94.6% FAR: 0.7% Allow: 12% | 88.3% FAR: 0.2% Allow: 2% | 91.8% FAR: 0.1% Allow: 2% | 95.3% FAR: 0.4% Allow: 8% | 96.5% FAR: 0.3% Allow: 10% |
LER Reduction %. FAR-bad = fraction of allowed shots that carry logical errors. Higher allow rate = more throughput retained.
As code distance grows, temporal correlation awareness becomes essential. SafetyGate maintains 88%+ LER reduction at every distance, with FAR-bad dropping below 1% at d=5 and above.
88% floor across all configs
Below 1% at d=5+
Explore the tradeoff between throughput cost and safety benefit. Each point is a validated noise regime. Slide to see how SafetyGate adapts.
Current Operating Point
d=5, STABLE
96.7%
LER Reduction
69.5%
Block Rate
30.5%
Throughput Retained
0.99%
FAR-bad
96.7% of errors eliminated
Click points on the chart or slide to explore how SafetyGate adapts to different noise conditions. Higher block rate = more aggressive filtering = better safety at throughput cost.
No. SafetyGate runs alongside existing decoders and does not modify correction logic.
Yes. SafetyGate is a conservative safety layer. It may veto shots that would decode correctly in order to reduce overall logical risk.
SafetyGate uses vendor-specific noise profiles but the approach is hardware-agnostic. Validated on IBM Heron (3 backends) and Rigetti Ankaa-3. Vendor-specific noise profiles with <0.5% cross-backend variance within IBM.
SafetyGate computes a risk score from error indicators.
High scores indicate error patterns that statistically correlate with failure.