GHZ three-qubit entanglement
Create one correlation shared coherently by three qubits.
Back to learning pathMulti-qubit entanglementWhy this experiment matters
What you will do
Use X-basis parity to distinguish GHZ coherence from a classical 000/111 mixture.
- 01
Create (|000⟩+|111⟩)/√2 with H and two CNOTs.
- 02
Measure fresh copies of all three qubits in the X basis.
- 03
Compare even and odd X-parity counts.
04 · PREDICT
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.
Make a prediction, then run the measurement to reveal the expected and sampled results.
Measurement results
What the result shows
Ideal GHZ+ has even X parity every time. Lost relative-phase coherence makes even and odd parity equally likely.
GUIDED VIDEO
Watch the experiment
Follow the experiment with English narration and English subtitles.
Use X-basis parity to distinguish GHZ coherence from a classical 000/111 mixture.
Full transcript5 · 1:00
- 01Overview
Use X-basis parity to distinguish GHZ coherence from a classical 000/111 mixture.
- 02Experiment steps 1
Create (|000⟩+|111⟩)/√2 with H and two CNOTs.
- 03Experiment steps 2
Measure fresh copies of all three qubits in the X basis.
- 04Experiment steps 3
Compare even and odd X-parity counts.
- 05What to observe
Ideal GHZ+ has even X parity every time. Lost relative-phase coherence makes even and odd parity equally likely.
06 · CHECK
Check what you learned
Make a prediction, then run the measurement to reveal the expected and sampled results.