Zero to Quantum — Lesson 1

Course

IBM Quantum Learning — Use a quantum computer today

Lesson

Build and run your first quantum program.

Goal

Build a two-qubit Bell-state circuit using Qiskit, run it on a simulator and a real IBM Quantum backend, then compare the results.

Concepts Covered

• Qubit
• Quantum circuit
• Hadamard gate H
• Controlled-X gate CX
• Bell state / entanglement
• Measurement
• Simulator vs real QPU noise

Circuit

The circuit prepares the Bell state:

q0: ──H──■──M
         │
q1: ─────X──M

Expected state:

$$|Φ⁺⟩ = (|00⟩ + |11⟩) / √2$$

Expected Result

On an ideal simulator, the measurement output should be approximately:

• 00: ~50%
• 11: ~50%
• 01 and 10: ~0%

On a real QPU, small noise may produce 01 and 10.

Files

• Zero_to_Quantum_lesson1_GitHub_ready.ipynb: cleaned notebook with no token.
• notes.md: short conceptual notes.
• requirements.txt: Python dependencies.
• .gitignore: protects secrets and temporary files.

Security Note

Never upload your IBM Quantum API token to GitHub. Use Colab Secrets or environment variables instead.