Quantum Incompatibility in Parallel vs Antiparallel Spins
The paper compares joint measurability for incompatible qubit observables using parallel and antiparallel spin-1/2 pairs. It finds that the antiparallel configuration uniquely allows for exact simultaneous prediction of three mutually orthogonal spin components, an advantage parallel states cannot offer. This enhanced compatibility also extends to more than three observables and has implications for estimating unknown measurement devices.