It has been recognised recently that the strange features of the quantum world could be used for new information transmission or processing functions such as quantum cryptography or, more ambitiously, quantum computing. These fascinating perspectives renewed the interest in fundamental quantum properties and lead to important theoretical advances, such as quantum algorithms and quantum error correction codes. On the experimental side, remarkable advances have been achieved in quantum optics, solid state physics or nuclear magnetic resonance. This book presents the lecture notes of the Les...