Bridge Concentration Index (M10036)
| Metric ID | M10036 |
|---|---|
| Category | onchain |
| Access | public |
| Classification | classic |
| Tier | basic |
| Computation | Classical + Quantum (hardware) + Quantum (simulated) |
| Computed by | Black Belt Labs |
| Freshness | fresh |
Quantum configuration
Every quantum calculation of this metric, with the machine and circuit setup it runs on. Hardware values come from real IBM quantum computers; simulator values from a classical simulation of the same kind of circuit.
| Method | Quantum computing on hardware (quant-hw) |
|---|---|
| Provider | IBM Quantum Platform (Open plan) |
| Machine | ibm_marrakesh (156 qubits) |
| Machine type | superconducting QPU (IBM Heron) |
| Qubits used | 4 |
| Circuits per run | 1 |
| Shots per run | 4,096 |
| Circuit depth | 9 |
| Two-qubit gates | 2 |
| Gate basis | cz, rz, sx, x (IBM Heron native) |
| Algorithm | two-copy collision test (purity of the flow-share state) |
| Profile | full |
| Error mitigation | dynamical decoupling + measurement twirling; no post-hoc correction |
| Hardware runs | 2 |
| Last run | 2026-10-05T06:31:05 |
| IBM job id | db1k37hb694s73dsd6tg |
| How measured | IBM job record (transpiled circuit stats) |
| Method | Quantum computing simulated (quant-sim) |
|---|---|
| Provider | Qiskit Aer simulator (IBM open-source software) on Google Cloud |
| Machine | aer_simulator |
| Machine type | classical simulator (CPU, noise-free) |
| Qubits used | 4 |
| Circuits per run | 1 |
| Shots per run | 4,096 |
| Circuit depth | 4 |
| Two-qubit gates | 2 |
| Gate basis | u, cx (Aer, flattened) |
| Algorithm | two-copy collision test (purity of the flow-share state) |
| Profile | full |
| Error mitigation | none (noise-free simulation) |
| How measured | recorded circuits, compiled to u/cx |
Personal metrics: figures are the maximum across submitted portfolios (circuit size follows portfolio size). Machine qubits is the size of the whole chip; qubits used is what this calculation needs.
Method comparison (experimental)
The same metric computed several ways on the same frozen inputs, one change at a time, so a gap between two rows has a known cause. Each plus/minus is the standard error of that value. How to read this, and how it scales.
Daily simulator-only comparison
Snapshot 20261008T1258_9c7692d6 · 2026-10-08 12:58 UTC
| Step | Method | Value |
|---|---|---|
| Classical, exact | classical | 51.8 |
| Production value (-1.0 h from the snapshot) | classical | 51.8 |
| Quantum simulator, ideal | quantum simulated | 51.8 |
| Quantum simulator, sampled | quantum simulated | 52.1 ± 0.9154 |
| Noisy device model | quantum simulated | 48.9 ± 0.9992 |
Quantum values are not expected to beat the classical value at these problem sizes. The purpose of this section is to show, with uncertainty, how and why the methods differ. Small samples: treat scores as indicative.
Hypotheses monitored by this metric
Access this metric
Query it via the Madjik API:
curl -H "X-API-Key: $MADJIK_API_KEY" \
https://api.madjik.io/v1/metrics/M10036