Quantum teleportation is the name given to the hypothetical process of transferring quantum information (the state of an atom or subatomic particle) from one location to another, without having that information travel through any physical space in between. If successful, quantum teleportation would allow for the instantaneous transport of data and matter across vast distances.
The idea of quantum teleportation was first proposed in 1993 by physicists Charles Bennett and Gilles Brassard, who also developed the first theoretical framework for its implementation. In 1997, another team of physicists succeeded in experimentally demonstrating quantum teleportation over a distance of 10 kilometers (about 6 miles). More recent experiments have pushed the distance limit even further, with scientists teleporting photons across China and even into space.
Despite these impressive feats, it’s important to note that quantum teleportation does not actually involve the literal “teleportation” or movement of matter from one place to another. Instead, it relies on a phenomenon known as “quantum entanglement” to achieve its remarkable results.
Quantum entanglement is a strange but well-understood property of certain particles that allows them to remain connected even when separated by great distances. This connection means that any change made to one entangled particle will instantly be reflected in its partner. For example, if two electrons are entangled and one is spin up, the other must be spin down—even if they are on opposite sides of the galaxy.
So how can this bizarre property be used for quantum teleportation? The key lies in taking advantage of another fundamental principle of quantum mechanics known as “superposition”. Superposition allows particles to exist simultaneously in multiple states or configurations—for example, an electron can be both spin up and spin down at the same time. This means that an entangled particle can act as a sort of “bridge” between two other particles in different locations (known as the “sender” and “receiver”). By manipulating the state of the sender particle, it is possible to encode information about its state onto the bridge particle—which can then be decoded by measuring the state of the receiver particle. Because no physical information has traveled between sender and receiver, we say that this process is “non-local”.