Quantum information technology: Theory and applications

In the last decade quantum information theory and technology evolve and show their great potential. There are a set of problems for which it´s more efficient and even not possible with classical communication to solve than with quantum equivalent. The best known example is Quantum Key Distribution, though there are quantum non-locality (entanglement), quantum teleportation, communication complexity and many more. Quantum communication relies on some phenomenon like entanglement which gives plenty of opportunities, but at the same time it´s very tricky. Present knowledge lets us define entanglement as a property of quantum system when two or more objects are linked together (quantum states).