Circuit Capstone

The capstone runs the whole course loop on one five-qubit circuit: build it, compute width, gate counts and depth by hand, write down a quantitative prediction, run it with a fixed seed, then break exactly one operation and locate the first wrong state. A circuit is finished when that full record is reproducible — not when the histogram merely looks plausible.

What does the capstone ask you to do?

Everything in this course compresses into one loop, executed on one shareable five-qubit circuit:

Build a five-qubit GHZ circuit (from Building GHZ States).
Analyse it statically: width, gate count, two-qubit count, depth, two-qubit depth (from Circuit Depth).
Predict the measurement outcome quantitatively, in writing, before running.
Run with a fixed seed and a fixed shot count, and compare against the prediction.
Break one thing deliberately, then locate the first wrong state like a debugger (from Debugging Quantum Circuits).
Report the whole record so someone else can reproduce it.

The ordering is deliberate. A prediction written after seeing results cannot falsify your mental model; a prediction written before can — and being falsified is where the learning is.