Quantum Superposition & Decoherence Simulator

A single qubit's state |ψ⟩ = α|0⟩ + β|1⟩ is more than "0 and 1 at once" — it is two complex numbers with definite magnitude and phase. This simulator draws those amplitudes as rotating phasors on the complex plane, tracks the coherence term ρ₀₁ that carries their relative phase, and lets you watch it decay as you dial up coupling to a simulated environment. Press Measure to collapse the state probabilistically according to the Born rule |amplitude|², or let Auto-measure run many trials so the outcome statistics converge visibly to the predicted probabilities — the same experiment, at vastly larger scale, that verifies quantum mechanics in the lab every day.