Cross-entropy benchmarking (XEB)
How closely a machine's output from random circuits matches the ideal, expressed as a fidelity between 0 and 1.
When results can be compared
Only comparable for the same number of qubits and circuit depth. Mostly used in quantum-advantage experiments.
Where it comes from
Google researchers (Boixo, Isakov, Smelyanskiy and colleagues), 2018. Note: Created by Google, a hardware maker.
- Type
- Benchmark, system level
- Unit
- fidelity
- Better is
- Higher
- Applies to
- gate-based machines
Results
| Machine | Value | Set-up | Published | Measured by | Grade | Record |
|---|---|---|---|---|---|---|
| Google Willow | 1 × 10⁻³ | 103 qubits depth 40 | 9 Dec 2024 | Maker | B | r-000004 |