# QC2.1 Phase Kickback and Controlled Operations

This skill introduces phase kickback as a fundamental mechanism used in many quantum algorithms. Learners examine how controlled operations transfer phase information onto control qubits and how this effect can be exploited to encode global properties of a function into measurable quantum states. 

## Requirements

* [[skill-tree:qc:1:3:b]]

## Learning Outcomes

* Describe the concept of phase kickback in controlled quantum operations.
* Interpret simple quantum circuits that demonstrate phase kickback.
* Calculate the phase acquired by a control qubit in basic phase kickback examples.