rung: 5
name: "Rosenfeld Direction"
description: "Identify which heuristics matter for cultivation/distillation workflows. Narrowest search space; only proven dimensions survive."
objective: "Determine which preparation, verification, and transpilation choices are load-bearing under factory-realistic conditions, as a precursor to distillation pipeline integration."

bootstrap_incumbent:
  seed_style: ry_rz
  encoder_style: cx_chain
  verification: z_only
  postselection: z_only
  ancilla_strategy: reused_single
  optimization_level: 3
  layout_method: dense
  routing_method: basic
  approximation_degree: 1.0
  target_backend: fake_brisbane
  noise_backend: fake_brisbane
  shots: 512
  repeats: 3
  notes: "Rosenfeld-direction incumbent — propagated from rung 4 winner."

search_space:
  max_challengers_per_step: 4
  dimensions:
    verification: [z_only, both]
    postselection: [z_only, all_measured]
    ancilla_strategy: [reused_single, dedicated_pair]
    optimization_level: [2, 3]
    shots: [384, 512, 768]

tier_policy:
  cheap_margin: 0.0005
  confirmation_margin: 0.0
  cheap_shots: 512
  expensive_shots: 2048
  cheap_repeats: 3
  expensive_repeats: 2
  promote_top_k: 1
  enable_hardware: false
  confirm_incumbent_on_hardware: true
  hardware_budget: 1

score:
  name: factory_throughput
  base_cost: 1.0
  cheap_quality:
    noisy_fidelity: 0.10
    logical_witness: 0.35
    codespace_rate: 0.20
    stability_score: 0.25
    spectator_alignment: 0.10
  expensive_quality:
    logical_witness: 0.40
    codespace_rate: 0.20
    stability_score: 0.30
    spectator_alignment: 0.10
  cost_weights:
    two_qubit_count: 0.12
    depth: 0.02
    shot_count: 0.00050
    runtime_estimate: 0.04
    queue_cost_proxy: 0.60

step_budget: 4
patience: 3

hardware:
  backend_name:
  channel:
  instance:
  token_env_var: QISKIT_IBM_TOKEN