Alphabeta Math
CounterexampleConstruction: AI-adaptedVerification: AI-generatedPipeline-generated
How statement and proof provenance work

The first chip identifies the source of the statement or construction; the second identifies the source of its local proof or verification.

  • Literature-sourced: the exact statement appears in a cited source; only wording and notation differ.
  • AI-adapted: a semantically identical restatement of literature-sourced material, modulo indexing, notation, and boundary cases adopted by the library.
  • AI-generated: a genuinely novel statement formulated by AI, with no source for the claim itself.

These labels describe origin, not correctness: citations and verification chips remain separate evidence.

Planar and periodic surface-code distances differ

Statement

At linear size three, the square planar surface code has asymmetric Z and X distances 3 and 4, whereas the periodic 3×3 toric code has distance 3 for both logical species and encodes two qubits. Thus the planar surface-code calculation cannot be used as the periodic torus calculation.

Facts & Assumptions

Given: The relative square-patch convention and the periodic toric-code convention, both with linear size three.

[F1]

Square planar surface code: the planar patch has left and right rough boundaries; its physical qubits and checks use relative boundary maps, not periodic incidence.

[F2]

Square planar surface-code distance and path count: for a d×d planar patch, the code encodes one qubit, has Z distance d, and has X distance d+1.

[F3]

Toric code distance is L: the periodic L×L toric code has distance L for both primal and dual nontrivial cycles.

[F4]

The periodic toric code encodes two qubits: the periodic toric code encodes two qubits.

[F5]

Noncontractible toric logical loops: the periodic code has nontrivial primal Z and dual X loop representatives, each supported on L edges.

Counterexample

1.1givenF2F3F4F5algebra

Set d=L=3. By [F2], the planar code has Z distance 3 and X distance 4, and encodes one qubit. For the toric code, [F3] gives the lower bound 3 for every nontrivial logical Pauli, while [F5] supplies a nontrivial three-edge representative of each pure species. Thus both species have distance 3; [F4] gives code dimension four. The distance profiles and code dimensions differ at the same linear size.

2.1F1F2F3algebra∎

The reason is already present in the hypotheses: [F1] uses relative boundary maps and rough edges, while [F3] uses periodic incidence on a closed torus. Therefore planar boundary paths and their asymmetric distance theorem do not establish torus winding classes, check relations, or toric distance. The distinction is a finite combinatorial one and does not require a physical interpretation.

Depends on

Used by

Nothing in the library uses this result yet.

Dependency tree · two levels

23 results within two dependency steps of this one, each drawn at its shortest distance from it. An arrow runs from a result to what uses it, so the chart reads left to right and ends at this result, which carries a heavier outline. Every node is a link to that result. Click elsewhere on the chart to enlarge it.

Sources