Grover search
Amplify one marked answer—and see why the number of iterations matters.
Back to learning pathQuantum algorithmsWhy this experiment matters
What you will do
See how phase marking and interference can reduce the work needed for unstructured search.
- 01
Create an equal superposition of four states.
- 02
Let the oracle flip only the target's phase.
- 03
Apply diffusion, then decide whether another iteration helps or overshoots.
Predict before you measure
Choose one answer to unlock the measurement.
INTERACTIVE
Interactive model
Move the control, then run a measurement. This is a teaching simulation—not hardware output.
Choose one answer to unlock the measurement.
Predict before you measureMake a prediction, then run the measurement to reveal the expected and sampled results.
Measurement results
What the result shows
For four states, one iteration raises the target from 25% to 100%; a second overshoots and returns it to 25%.
GUIDED VIDEO
Watch the experiment
Follow the experiment with English narration and English subtitles.
See how phase marking and interference can reduce the work needed for unstructured search.
Full transcript5 · 1:00
- 01Overview
See how phase marking and interference can reduce the work needed for unstructured search.
- 02Experiment steps 1
Create an equal superposition of four states.
- 03Experiment steps 2
Let the oracle flip only the target's phase.
- 04Experiment steps 3
Apply diffusion, then decide whether another iteration helps or overshoots.
- 05What to observe
For four states, one iteration raises the target from 25% to 100%; a second overshoots and returns it to 25%.
06 · CHECK
Check what you learned
Make a prediction, then run the measurement to reveal the expected and sampled results.