Quantum ToolkitTypesStateMethodssquared_normOn this pagesquared_norm Method of State. squared_norm() -> real Computes the squared norm of the quantum state. Returns the squared L2 norm ∣∣ψ∣∣2=⟨ψ∣ψ⟩\vert \vert \psi \vert \vert ^2 = \langle \psi \vert \psi \rangle∣∣ψ∣∣2=⟨ψ∣ψ⟩ of the quantum state.