QTM104 · Quantum Gates and Circuits
About Course
Learn the standard quantum gate set, how multi-qubit gates create entanglement and logic, and how circuits are compiled to the native gates and connectivity of real hardware.
Who it is for
Learners who understand qubits and measurement and want to design, read and optimize quantum circuits.
Prerequisites
QTM103; comfort with matrix multiplication from QTM102.
What you will be able to do
- Apply the Pauli, Hadamard, phase (S, T) and rotation gates and predict their effect on a state
- Use CNOT, CZ, SWAP and Toffoli gates to build reversible logic, including a quantum half adder
- Explain phase kickback and use circuit identities to simplify circuits
- Transpile a circuit for a real device and compare depth and two-qubit gate counts across optimization levels
Lessons
- Lesson 1 · Single-qubit gates
- Lesson 2 · Multi-qubit gates and reversible logic
- Lesson 3 · Circuits on real hardware: compilation
- Lesson 4 · Lab and assignment
Lab: Build, simplify and transpile circuits
You design a quantum half adder and a teleportation circuit visually in IBM Quantum Composer and inspect their statevectors. You then rebuild them in Qiskit, transpile them for a simulated IBM device at optimization levels 0 to 3 and compare the resulting depth and two-qubit gate counts. No paid hardware time is needed.
Free tools: IBM Quantum Composer (free account) and Google Colab with Qiskit and a fake backend from qiskit-ibm-runtime
Assessed assignment
Design a quantum circuit that implements a three-input "majority" function: the output qubit should be 1 when at least two of three input qubits are 1. Verify it on all eight inputs with a simulator and present a truth table. Then transpile it for a fake IBM backend at optimization levels 0 and 3 and report depth, total gates and two-qubit gates. Explain in one page which circuit identities or layout choices reduced the cost and propose one further manual simplification.
| Criterion | Weight | What excellent work looks like |
|---|---|---|
| Correct reversible logic | 35% | Circuit returns the correct majority output for all eight inputs, with inputs preserved. |
| Verification evidence | 20% | Truth table and simulator outputs are complete and clearly presented. |
| Transpilation analysis | 30% | Metrics are reported accurately for both levels and the reasons for differences are explained correctly. |
| Optimization insight | 15% | Proposes a valid further simplification using circuit identities or qubit layout. |
Portfolio piece
A documented set of quantum circuits (half adder, teleportation, majority function) with transpilation metrics.
Next step
Continue with QTM105 · Programming Quantum Circuits with Qiskit · 8 hours · $56.00
Course Content
QTM104 · Quantum Gates and Circuits (6 h)
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Lesson 1 · Single-qubit gates
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Lesson 2 · Multi-qubit gates and reversible logic
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Lesson 3 · Circuits on real hardware: compilation
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Lesson 4 · Lab and assignment
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QTM104 Assessment · Quantum Gates and Circuits
