Cold Start

Zero prerequisites. Zero theory. You copy six lines, hit Run, and see quantum entanglement rendered as a chart.

Paste, run, ignore the syntax. We’ll explain everything in modules 1 through 4. For now, the point is to see it work.

from qiskit import QuantumCircuit, execute, Aer

qc = QuantumCircuit(2, 2)
qc.h(0)                # put q0 in superposition
qc.cx(0, 1)            # entangle q0 and q1
qc.measure([0, 1], [0, 1])

result = execute(qc, Aer.get_backend('qasm_simulator'), shots=1024).result()
print(result.get_counts())  # → {'00': ~512, '11': ~512}

Two bars — |00⟩ around 50%, |11⟩ around 50%. Nothing in |01⟩ or |10⟩. The two qubits are perfectly correlated. Neither is 0 or 1 until measured; whichever one you measure, the other agrees.

Delete the qc.cx(0, 1) line from your Colab. Predict what you’ll see in the histogram — then re-run.

You have a working Qiskit install, a saved notebook, and one measured entanglement.

You do not yet have any idea why. That’s what modules 1–4 fix — and you’ll debug what you cannot describe.

The threshold jumps to 400 by the capstone. You’ll get there.