Measurement bases
Measure the same |+⟩ state in the Z or X basis and compare the outcomes.
Back to learning pathPhase, bases, and gate orderWhy this experiment matters
What you will do
Learn that measurement asks a basis-dependent question; it does not reveal one basis-independent hidden bit.
- 01
Prepare the qubit in |+⟩ with H.
- 02
Choose the Z basis or X basis.
- 03
Measure fresh preparations and compare the two distributions.
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
In the X basis, |+⟩ gives + with certainty. In the Z basis, the same state gives 0 and 1 equally often.
GUIDED VIDEO
Watch the experiment
Follow the experiment with English narration and English subtitles.
Learn that measurement asks a basis-dependent question; it does not reveal one basis-independent hidden bit.
Full transcript5 · 1:00
- 01Overview
Learn that measurement asks a basis-dependent question; it does not reveal one basis-independent hidden bit.
- 02Experiment steps 1
Prepare the qubit in |+⟩ with H.
- 03Experiment steps 2
Choose the Z basis or X basis.
- 04Experiment steps 3
Measure fresh preparations and compare the two distributions.
- 05What to observe
In the X basis, |+⟩ gives + with certainty. In the Z basis, the same state gives 0 and 1 equally often.
06 · CHECK
Check what you learned
Make a prediction, then run the measurement to reveal the expected and sampled results.