Explore quantum entanglement: prepare four Bell states, measure Alice and Bob's qubits, observe perfect correlation, and run a CHSH inequality test that demonstrates quantum nonlocality.
Two entangled qubits share correlations that cannot be explained by any local hidden-variable theory (Bell's theorem). The CHSH parameter S measures these correlations: S ≤ 2 classically, but quantum mechanics predicts S = 2√2 ≈ 2.828.
Select a Bell state (Φ+, Φ−, Ψ+, Ψ−). Measure Alice's and Bob's qubits to see correlated outcomes. Run the CHSH test — accumulate statistics and watch S converge to 2√2, violating the classical bound.
John Bell proved in 1964 that no local hidden-variable theory can reproduce all quantum predictions. The 2022 Nobel Prize in Physics honoured Aspect, Clauser and Zeilinger for experiments confirming Bell inequality violations.