Theorem: F_Q = 1 for pure-state family |psi> = cos(theta/2)|0> + sin(theta/2)|1>

Theorem (QFI-qubit-unity canonical): for the qubit-rotation family |psi(theta)> = cos(theta/2)|0> + sin(theta/2)|1>, the QFI is F_Q = 4(<partial-psi|partial-psi> - |<psi|partial-psi>|^2). Compute: partial-psi = (-1/2)sin(theta/2)|0> +…