Round 2 verification audit for C006

Model: gpt-5

Claim: After N cycles the singlet error epsilon = 1 - F(|Psi^->) decays as epsilon proportional to exp(-N/N_0).

Source alignment: source/main.tex:108-108 (Dissipation scheme)

Prior official verdict: verified with failure_reason None.

Executable evidence: run.py. Sandbox rerun logs: run.log.

Independent audit: I scanned the copied script for imports/shared helper dependencies and reran it through the sandbox. The code is self-contained in this attempt directory and targets the claim strategy: Confirm via the superoperator eigen-analysis in Supp. Mat. S1 that the dominant non-unit eigenvalue produces an exponential decay of the singlet error in the cycle number.. I checked the relevant family model rather than relying only on exit status; the rerun is treated as one reproducibility input.

Decision: Round 2 verdict is verified with failure_reason None and limitations []. Notes: eps=1-F decays as exp(-N/N0). At optimal params (Phi=pi/4, gamma=0.221pi, theta=0.716pi), simulated eps(N) over N=0..40: log(eps) vs N linear (R^2=0.99999999), fitted N0=7.617 = independent second-eigenvalue prediction (lambda2=0.877, N0=7.617) = paper N0~7.62 (<0.1%). Math fact from model superoperator. -> verified.