Abstract
Quantum superposition, the cornerstone of the second quantum revolution, is a very fragile property : it disappears as soon as the system is exposed to external disturbances, such as fluctuating magnetic or electric fields. In this lecture, we will introduce the notion of decoherence using simple physical models, before showing how these processes can be measured and what techniques can be used to mitigate them. We will then be able to present the DiVincenzo criteria, necessary for the realization of a quantum computer, and give a brief overview of the different experimental platforms and the main sources of decoherence that affect them.
