1. The Second Quantum Revolution

1.1 From Fundamental Physics to Quantum Information

Quantum mechanics has profoundly transformed our understanding of the physical world and enabled technological advances essential to the information society, such as the transistor, the laser, and hard drives – collectively referred to as the “first quantum revolution.” During the 20th century, it was demonstrated that the quantum states of individual systems (atoms, electrons, photons) enable unprecedented information processing, surpassing classical paradigms thanks to fundamental properties such as superposition, entanglement, Heisenberg’s uncertainty principle, non-cloning, matter-wave interference, and indistinguishability. These principles form the foundation of an intrinsically physical and quantum information theory...