# QC1.3 Multi-Qubit Systems and the Gate Model of Quantum Computation

This skill extends quantum computation to systems composed of multiple qubits. Learners examine how multi-qubit states are represented, how quantum operations scale beyond single-qubit systems, and how entanglement enables computational behaviours that have no classical analogue. The gate model of quantum computation is introduced as a framework for describing quantum algorithms.

## Requirements

* [[skill-tree:qc:1:1:b]]
* [[skill-tree:qc:1:2:b]]

## Learning Outcomes

* Explain how multi-qubit quantum states are represented using tensor products.
* Differentiate between sequential and parallel applications of single-qubit gates in multi-qubit systems.
* Describe the function of common multi-qubit gates, including controlled-NOT (CNOT) gates and SWAP gates, which exchange the states of two qubits.
* Explain the concept of entanglement and describe Bell states as canonical examples.
* Summarise the impact of entanglement on the classical simulability of quantum systems.
* Describe how measurement operates in multi-qubit systems.
* Explain the gate model of quantum computation and the notion of universal gate sets.