The experiment studio
Choose a model, make a prediction, then change one thing at a time. Every experiment runs on your device. Exact probabilities and finite measurement samples are shown separately.
Qubit explorer
Prepare a pure qubit, apply gates, then compare amplitudes, phases and Z-basis probabilities. Reset restores the initial preparation shown by the lesson’s controls.
Prepare your experiment using the controls. Record a prediction, then reveal the statevector or run the experiment.
Changing the preparation or circuit starts a new prediction.
Take it further
Prepare θ = 120°, φ = 90°. Predict both complex amplitudes. Then change φ without changing θ.
Initial setup · reference state
| Basis | Amplitude a + bi | Magnitude | Phase (rad) | Probability |
|---|---|---|---|---|
| |0⟩ | 1 + 0i | 1.000000 | 0.000000 | 100.0% |
| |1⟩ | 0 + 0i | 0.000000 | undefined | 0.0% |
Signs and complex phases are part of the state. Phase is undefined for a zero amplitude. A shared global phase changes no probabilities; relative phases can affect a later operation. Values are rounded to six decimal places.
Prediction to try: Predict the amplitudes and Z-basis probabilities for the preparation and gates you have chosen. If starting from |0⟩, what will H do?
Challenge: Prepare θ = 120°, φ = 90°. Predict both complex amplitudes. Then change φ without changing θ.
Open the live experiment studioWhat these experiments model
Section titled “What these experiments model”The quantum experiments use small, ideal, complex statevectors with q0 on the left. QFT uses the positive-exponent convention with numeric output order. Phase estimation assumes an exact eigenstate. The BB84 model separately simulates preparation, measurement, intercept–resend and channel bit flips.
These are educational simulations, not hardware execution or a secure communication service. See the model conventions and full experiment roadmap for assumptions and planned tools.