Quantum Computing.
|100⟩⟨100| + |101⟩⟨101| + |110⟩⟨110| + |111⟩⟨111| or, succinctly, U_oracle = I — 2 |011⟩⟨011| So U_oracle |μ⟩ = (2√2)-1 (|000⟩ + |001⟩ + |010⟩ — |011⟩ + |100⟩ + |101⟩ + |110⟩ + |111⟩) The second stage is called a diffusion transform. This is a unitary transformation that replaces each amplitude zj