DTU to develop quantum communication
Quantum mechanics—or quantum physics—is a branch of physics concerned with the properties of matter and electromagnetic fields at particle level.
Three basic principles of quantum mechanics:
An object in the microscopic world can be in a superposition state, which means that it can assume two values at the same time. For example, the object can be in two places in space at the same time. This puts it far outside the realms of classical physics, which says that an object can only have one value.
If you perform a measurement on an object, such as an atom—which can be in two places at the same time—the atom will collapse at the moment of being measured and assume only one value. That means if the atom was in a superposition of being in two places at the same time, following measurement it will only be in one place.
Two particles can be linked to each other, irrespective of how far they are from each other in the universe, and if you change one particle, the other will be able to ‘feel’ the change. They are said to be quantum correlated. This is called entanglement.