What is Quantum Information?
Information technologies have shaped modern civilizations. Until very recently, the theory of computation was restricted only to information encoded in classical states and where processing could be described by classical mechanics. But the laws of quantum mechanics allow a more general class of physical states and operations, and open the door to a more general theory of information. The reason why quantum mechanics was not included at first in information theory (information theory was discovered after quantum mechanics!)  was that quantum states are very sensitive to thermal noise and were very difficult to manipulate. Most researchers simply thought that controlling quantum states was a crazy idea, and were not interested in a more general theory of information. Recent advances in quantum optics and nanotechnology have brought in a different perspective. The devices used for computation are smaller and smaller every year, and quantum effects in those will soon be dominant. A small quantum structure can now be controlled very well, and quantum correlation observed between photons has been proved to be very robust when communicating over many kilometers.

Quantum information is the study of the new possibilities offered by quantum technologies. It has been discovered that some quantum algorithms could outperform the best known classical algorithms essential in some crucial day-to-day applications. Quantum mechanics could also be used in cryptography to obtain a deeper level of security that was not possible classically. A large part of the research is to try to investigate other possible applications and to obtain a better understanding of quantum mechanics. From an experimental point of view, we want to improve our control of larger and more complex quantum structures.