What is “quantum teleportation”?

Out of all the concepts that have appeared in science fiction, one of the most ‘science fiction-y’ of them all is the idea of teleportation — near instantaneous movement from one location to another, such as the transporters in Star Trek. I call this one of the most ‘science fiction-y’ because it seems like one of the most impossible technologies, going against our common sense of how the world and science works! However, it turns out that in the realm of quantum physics, it is possible to “teleport” a quantum state from one particle to another. The idea was first proposed in the 1990s and has been confirmed experimentally. It is a far cry from a Star Trek-like transporter but it is another excellent illustration of how quantum physics breaks our intuition of the universe. In this post, I thought it would be fun to try to explain exactly what it is all about! We’ll use a few formal equations, but the most we’ll do is add and subtract things and substitute from one equation to another.…