C058 - For the protocol the fidelity with |Psi^-> is extracted after 80 cycles, while for the co...
Verdict: partial
Location: Supp. Mat. S3
Type / expected artifact: empirical / math / numeric
Claim: For the protocol the fidelity with |Psi^-> is extracted after 80 cycles, while for the comparison single-loop (length t) and two-loop (length t sqrt(2)) MS gates the fidelity is taken against (|down,down> - i|ee>)/sqrt(2).
Models: extraction claude-opus-4-8; verification gpt-5; verification_chain claude-opus-4-8 -> gpt-5; verdict_chain partial -> partial.
Limitations: paper_text_only_reimplementation.
Source location(s): source/supp_content.tex:100-101 (Supp. Mat. S3).
Conclusion
Descriptive simulation-protocol claim corroborated structurally with the self-contained model. MS gate from H_A reaches the triplet Bell target (|dd>-i|ee>)/sqrt2 (fidelity 1.0); protocol steady state is |Psi-> (F=1) and 80 cycles converges (F=0.99998 from |dd>, N0=7.62 so 80 = 10.5 N0), confirming 80 cycles is a sensible fidelity-extraction point. Single-loop (length t) vs two-loop (length t*sqrt2) are path/duration descriptors of the same net area. This is a descriptive protocol choice, not a reproduced measurement, so capped at partial.
Verification details
Executable rerun: run.py exited 0 in 0.522s; log verification/C058/attempts/R002/run.log.
Output excerpt:
=== Structural corroboration of the simulation protocol (C058) ===
[single-loop MS (length t)] target (|dd>-i|ee>)/sqrt2: fidelity at MS Bell area = 1.000000 -> True
[two-loop MS (length t*sqrt2)] target (|dd>-i|ee>)/sqrt2: fidelity at MS Bell area = 1.000000 -> True
-> the comparison MS gates target the triplet Bell state (|dd>-i|ee>)/sqrt2,
reproduced exactly from H_A. The two-loop phase-modulated gate (length
t*sqrt2) implements the same net entangling area as the single loop.
[protocol] steady-state singlet fidelity = 1.000000 (eig=1.000000-0.000000j)
-> steady state is |Psi-> : True
N= 16 cycles from |dd>: singlet fidelity = 0.891177
N= 40 cycles from |dd>: singlet fidelity = 0.995341