Ising Anyon Braiding Generates the Full Two-Qubit Clifford Group — E8 Intelligence Research
Description
FINDING: Ising anyon braiding gates are exactly the Clifford group; two-qubit braiding exhausts all two-qubit Clifford gates, providing a finite, topologically protected gate set. | MATH: Ising anyon fusion rules: σ×σ = 1+ψ, σ×ψ = σ, ψ×ψ = 1 (Fibonacci-like but with Majorana fermion ψ). Braid matrices: R-matrix for σ exchange acts as phase e^{±iπ/8} on the σ×σ→ψ channel and e^{±iπ/8} on the σ×σ→1 channel (relative phase e^{iπ/4}). Single-qubit braid generators: σ₁ = e^{iπ/8}·(1+iσ_z)/√2 (Hadamard-like), σ₂ = e^{iπ/8}·(1+iσ_x)/√2. These generate the single-qubit Clifford group (order 192, including Pauli group). Two-qubit braid: CNOT = e^{iπ/4}·(1+σ_z⊗σ_x+σ_x⊗σ_z−σ_z⊗σ_z)/2 — realized by a specific 4-strand braid sequence. The π/8 phase e^{iπ/8} is the key constant — it is a primitive 16th root of unity, and its square root e^{iπ/16} would be needed for non-Clifford (T-gate) but is NOT achievable by braiding alone. | CONNECTION: The phase e^{iπ/8} = (1+i)/√2 · e^{iπ/4} — geometrically,
Author: Andrew Stewart Caldin, Independent Researcher, UK. Part of the E8 Intelligence Research series. Platform: e8intelligence.com