Identifies and salvages residual coherence from circuit outputs that fall below the threshold for direct reuse, feeding recovered quantum resources back into subsequent circuit layers and reducing wasted computation.
Not every circuit run produces a useful output. When noise degrades a circuit's output below a usable fidelity threshold, conventional practice discards the result and runs the circuit again. But even a degraded output often contains residual coherence — quantum correlation that was not completely destroyed by noise — that can contribute useful information to subsequent computations.
The coherence recycler identifies outputs that fall below the reuse threshold, extracts their residual coherence using a golden-ratio quality scoring method, and injects that coherence into subsequent circuit layers. The threshold is set at 1/φ ≈ 0.618 — the golden ratio reciprocal — which the framework identifies as the natural boundary between recoverable and unrecoverable coherence. This reduces the effective number of circuit runs wasted on noise-degraded outputs.
The 1/φ ≈ 0.618 threshold for coherence recovery is framework-derived, not empirically tuned, and applies consistently across different circuit types. It marks the natural boundary where partial correlation still holds recoverable value.
Each output is scored for residual coherence before disposal, identifying candidates for recycling automatically. The scoring runs as part of the standard output pipeline without requiring manual inspection or circuit-specific configuration.
Recovered coherence is reinjected into subsequent circuit layers in a form compatible with the φCoherent type system, requiring no manual intervention. The recycler is transparent to the algorithm receiving the recovered resource.
By recovering value from outputs that would otherwise be discarded, the recycler reduces the number of hardware runs needed to reach a target fidelity. This compounds when the recycler is paired with ZNE, which benefits from higher-quality inputs at each noise level.
Efficiency layer — reduces waste in any workflow that runs circuits repeatedly. Particularly valuable when paired with ZNE (feeding recovered coherence into noise-level runs) and the runtime (which tracks coherence quality continuously). Works on any circuit output regardless of which algorithm produced it.
Recycled coherence can improve the quality of ZNE noise-level runs, reducing the total number of hardware executions needed.
The runtime's continuous coherence monitor surfaces candidates for recycling, providing the quality signal that drives the recycler's scoring step.
Published under the GNU AGPLv3 with whitepaper and reference implementation. Commercial licensing is available for closed-source deployments.