C034 - The unitary gate based on the same Hamiltonian H_A produces (|down,down> - i|ee>)/sqrt(2)...
Verdict: verified
Location: Experimental error analysis
Type / expected artifact: citation / citation
Claim: The unitary gate based on the same Hamiltonian H_A produces (|down,down> - i|ee>)/sqrt(2) with a fidelity >~ 99% [Mehta2020].
Models: extraction claude-opus-4-8; verification gpt-5; verification_chain claude-opus-4-8 -> gpt-5; verdict_chain verified -> verified.
Source location(s): source/main.tex:155 (Experimental error analysis).
Conclusion
Mehta2020 = 'Integrated optical multi-ion quantum logic' (arXiv:2002.02258, Nature 586, 533), companion paper from the same group, fetched full text. It reports a unitary Molmer-Sorensen (sigma_x sigma_x) entangling gate that ideally produces exactly (1/sqrt(2))(|down,down> - i|up,up>) = (|dd> - i|ee>)/sqrt(2) starting from |down,down>, with measured Bell-state fidelity 99.3(2)% (parity-oscillation contrast 99.2(2)%, gate-time populations 99.4(1)%). Paper claim: same H_A-type unitary gate produces (|dd> - i|ee>)/sqrt(2) with fidelity >~99%. State form, gate Hamiltonian type, and fidelity (99.3% >= 99%) all match. Conclusion: verified.
Verification details
Citation evidence excerpt: The cited work reports, on the same integrated-photonics ion-trap apparatus, a unitary Molmer-Sorensen (sigma_x sigma_x) entangling gate that ideally produces exactly (|down,down> - i|up,up>)/sqrt(2) = (|dd> - i|ee>)/sqrt(2), with a measured Bell-state fidelity of 99.3(2)%, i.e. >~99%. State form, gate Hamiltonian type, and fidelity all match the claim from full text. VERDICT: verified.