Benchmarks Overview
Q-Memory Performance Benchmarks
Section titled “Q-Memory Performance Benchmarks”This page summarises the performance benchmarks and validation milestones for the Q-Memory photonic platform across its development phases.
Phase 0 Validation Benchmarks
Section titled “Phase 0 Validation Benchmarks”Phase 0 is a structured engineering experiment designed to answer specific pass/fail questions before committing to full-scale fabrication. It is not a performance benchmark — it is a component qualification run.
Phase 0 Pass Criteria
Section titled “Phase 0 Pass Criteria”| Test | Metric | Pass Threshold |
|---|---|---|
| Waveguide propagation loss | Loss per unit length | < 2 dB/cm (Phase 0 target) |
| Phase element response | Power for π phase shift | < 25 mW |
| Phase element speed | Response time | < 10 µs |
| Beam splitter accuracy | Extinction ratio | > 25 dB |
| Optical coupling efficiency | Insertion loss per facet | < 2 dB |
| Two-photon interference | Hong-Ou-Mandel visibility | > 90% |
| Mesh programmability | Decomposition error | < 1% |
| Phase stability | Drift rate | < 5 mrad/minute |
If these pass, Phase 1 is approved. Failures drive specific design changes rather than project cancellation.
Projected Performance: Optical Components
Section titled “Projected Performance: Optical Components”Based on published literature from comparable silicon nitride photonic platforms:
| Component | Target Performance | Literature Basis |
|---|---|---|
| Waveguide propagation loss | < 0.5 dB/m (Phase 1+) | Demonstrated in silicon nitride platforms |
| Beam splitter insertion loss | < 1 mdB per 50:50 split | Directional coupler literature |
| Waveguide crossing loss | ~1–2 mdB per crossing | Silicon nitride crossing demonstrations |
| Edge coupler insertion loss | ~50–100 mdB per facet | Inverse taper demonstrations |
| Photon detection efficiency | > 98% (cryogenic detectors) | Superconducting nanowire literature |
Quantum Application Benchmarks
Section titled “Quantum Application Benchmarks”Quantum Key Distribution
Section titled “Quantum Key Distribution”- Entangled pair generation rate: Determined by pump power and ring resonator quality factor; targets MHz-scale rates on-chip
- Photon indistinguishability: > 99% required for long-distance QKD; target > 90% for Phase 1 demonstration
- Telecom wavelength compatibility: 1550 nm C-band — directly compatible with standard fibre infrastructure
Quantum Random Number Generation
Section titled “Quantum Random Number Generation”- Generation rate: Limited by detector dead time; target > 100 Mbit/s certified random bits
- Certification: Quantifiable against quantum optics models — not pseudo-random
Quantum Sampling
Section titled “Quantum Sampling”- Classical hardness threshold: Estimated to require ~50 photons across ~100 modes for practical quantum advantage
- Phase 1 target: Demonstrate interference at 16–32 photon scale; validate sampling fidelity
AI Acceleration Benchmarks
Section titled “AI Acceleration Benchmarks”The optical matrix-vector multiplication performance scales with chip size and detector speed.
Matrix Operation Latency
Section titled “Matrix Operation Latency”| Matrix Size | Optical Propagation Time | Detector Readout | Total Latency |
|---|---|---|---|
| 4 × 4 (Phase 0) | < 1 ns | ~10 ns | ~10 ns |
| 64 × 64 (Phase 1) | < 5 ns | ~10 ns | ~15 ns |
| 256 × 256 (Phase 2) | < 20 ns | ~10 ns | ~30 ns |
For comparison, a conventional GPU performing a 256 × 256 matrix multiplication is typically limited by memory bandwidth — reading the weight matrix at ~100 ns–10 µs depending on caching.
Non-Volatile Weight Storage Power
Section titled “Non-Volatile Weight Storage Power”A key benchmark for the photonic platform’s AI acceleration mode is the power saved by using non-volatile optical memory versus continuous phase control:
| Network size (optical elements) | Continuous thermal phase control | Non-volatile optical memory |
|---|---|---|
| 64 elements | ~1 W | 0 W |
| 256 elements | ~4 W | 0 W |
| 1024 elements | ~15 W | 0 W |
This saving is structural — the non-volatile optical memory holds the weight matrix configuration with zero ongoing power. The saving scales linearly with network size.
Loss Budget vs Fault-Tolerance Threshold
Section titled “Loss Budget vs Fault-Tolerance Threshold”Fault-tolerant photonic quantum computing requires keeping total photon loss below approximately 2.7% per photon path (based on published fault-tolerance thresholds for fusion-based quantum computing architectures).
Current best-demonstrated systems in research literature are estimated at approximately 3.2% per photon — just above the threshold. The Phase 1 design targets closing this gap.
| Loss source | Estimated contribution |
|---|---|
| Photon source coupling into waveguide | ~0.7% |
| Chip edge coupler | ~1.2% |
| Waveguide routing (10 cm path) | ~0.01% |
| Beam splitter elements | ~0.1% per element |
| Detector coupling and efficiency | ~0.5–1.0% |
| Total (estimated) | ~2.5–3.5% |
Achieving < 2.7% requires careful management of every element in the path and is the primary engineering constraint for fault-tolerant operation.