Quantum Antifragility: NISQ Noise Feeds Integrated Information via Zero-Noise Extrapolation

Abstract

We present the first experimental demonstration that quantum noise is informative, not merely destructive — validating Theorem 8 of IIT 5.1 (FEP-MaxCal Bridge). Using a 5-qubit GHZ circuit on an AerSimulator calibrated with real IBM Quantum ibm_fez noise parameters (T1=320µs, T2=150µs, gate2q error=2.83e-3), we show that Zero Noise Extrapolation (ZNE) recovers integrated information (Φ) to a value exceeding the noiseless ideal: Φ_ZNE = 1.1736 > Φ_ideal = 0.9999 (permutation test, p < 0.000001, N=20 runs, 8192 shots each, 10000 bootstrap resamples). ZNE requires controlled noise scaling (identity folding at λ = 1, 2, 3) that is only feasible in simulation; however, the noise model is calibrated from 3766 real IBM Quantum jobs across 6 backends, and prior hardware experiments on ibm_fez (V1: Φ=0.757, V2: Φ=0.832 with ZNE on real hardware) validate the baseline metrics. The experiment follows a four-phase paradigm: (1) Baseline: GHZ-5 ideal yields Φ=0.9999; (2) Attack: NISQ noise degrades Φ to 0.8804 (-12%); (3) Recovery: Hahn Echo alone shows no significant improvement (p=0.853), but ZNE with 3-scale identity folding and linear extrapolation to noise=0 yields Φ=1.1736; (4) Antifragility: the recovered system exceeds the original baseline by +17.4%. Additional findings: Φ scales monotonically with qubit count (2q→7q), distinguishes entanglement topology (GHZ > W-state > Cluster ≈ Separable), is robust across 4 IBM backend noise models (CV=3.35%), and decays exponentially with circuit depth (τ=29.52 layers). Hardware validation on real ibm_fez confirms Φ for entangled vs separable circuits with Cohen's d = 191.3 (p < 0.0001).