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S1f IBM Quadrature Mechanism Check

Date: 2026-05-20 Backend: ibm_kingston Experiment ID: s1f_quadrature_mechanism_check_2026-05-20 Parent experiment: s1_dynamic_feedback_preregistration_2026-05-06

Artefacts

  • Readiness: data/s1_feedback_loop/s1f_xy_observable_readiness_ibm_kingston_20260520T142213Z.json
  • Readiness SHA-256: d8b5e0980ab3966ec62eb29f25192cd387b4f2bc420126ea0f8f9d9fbc45d3ea
  • Raw counts: data/s1_feedback_loop/s1f_xy_observable_raw_counts_ibm_kingston_20260520T142213Z.json
  • Raw counts SHA-256: 1be95f9996fb56e1f7e8d39921e9c46c65b1d8f4622bb46ac7d3789a592d9e87
  • Analysis: data/s1_feedback_loop/s1f_xy_observable_analysis_ibm_kingston_20260520T142213Z.json
  • Analysis SHA-256: 17b37753460137c796a5fb8c52784ce694d7ce4ffb63e55c92853abe8f91313e

Purpose

S1f is a narrow mechanism-discrimination lane for the S1 paper. It keeps only the S1d/S1e-favoured policy, current_shallow_positive, and tests whether the previously repeated YYI response localises to one quadrature or instead appears across transverse or population controls.

Configuration:

  • n_rounds=1
  • correction angle 0.06
  • base gain 0.4
  • repetitions 5
  • observables: YYI, XXI, XYI, YXI, ZZI

Readiness

All arms passed readiness on ibm_kingston. Maximum transpiled depth was 237. Total estimated QPU seconds were 50.0 under the 60.0 second ceiling.

Execution

The 10 IBM jobs completed:

d86s75h789is73903oug, d86s779789is73903p00, d86s791789is73903p60, d86s7atg7okc73eli47g, d86s7d2s46sc73f7dko0, d86s7eop0eas73dldb7g, d86s7gop0eas73dldbeg, d86s7m8p0eas73dldbp0, d86s7odg7okc73eli530, d86s7q8p0eas73dldbtg.

Results

Feedback minus matched open-loop control:

Observable Feedback Control Feedback minus control
XXI 0.2187500000 0.2175781250 0.0011718750
XYI 0.1617187500 0.1566406250 0.0050781250
YXI 0.2242187500 0.2136718750 0.0105468750
YYI -0.0445312500 -0.0242187500 -0.0203125000
ZZI 0.6523437500 0.6480468750 0.0042968750

Mean absolute feedback-control separation: 0.0082812500.

Interpretation

S1f does not support a stable quadrature-localised positive YYI mechanism in this later calibration window. The previously repeated S1d/S1e YYI response was large and positive, but S1f measures a small negative YYI delta while the cross-quadrature (XYI, YXI) and population (ZZI) controls remain small.

The conservative conclusion is stronger and more honest than a promoted controller claim: the S1 direct-XY response is structured and can repeat within a calibration window, but it is not calibration-window stable enough to promote the tested feedback law as a robust controller. S1f should be the final hardware run for this paper unless a future redesigned policy is preregistered.