No Beaming Up, Yet
As fascinating as the image it conjures up, quantum teleportation is not the same as teleportation you see in psychic Pokémon, or what you see Scotty doing in Star Trek. Still, quantum teleportation has its own kind of coolness.
Simply put, quantum teleportation is a process of transferring quantum information from one particle to another without the actual particles meeting. It involves a principle called entanglement, where the quantum state of one particle can be instantly shared by another regardless of distance.
As the International Business Times succinctly explains:
Here’s how quantum teleportation works. Imagine, if you will, three people — Alice, Bob and Charlie. Alice wants to send information to Bob. In order to do so, she prepares a photon she wants to teleport and sends it to Charlie, while Bob entangles two photons and sends one of them to Charlie. When Charlie receives the two photons — one each from Alice and Bob — he carries out what’s known as a Bell-state measurement, which actually forces the two to become entangled. This, in turn, causes the photon Bob has to collapse into the state of Alice’s original photon, thereby teleporting quantum states between Alice and Bob, who can, in theory, be separated by a distance of miles.
Scientists have been playing around with the concept and testing it out in labs. In 1997, teleportation was tried at an 800-meter distance between two particles in the same lab. Then in 2012, the record was set at over 143 kilometers (88.8 miles), when the teleportation happened between two particles in two separate locations in the Canary Islands.
Since then, the possibility of conducting secure quantum teleportation in relatively uncontrolled areas has been explored, until quite recently when it was deemed possible.
Photons and Potential
Fast-forward to today. Two separate teams of researchers from Calgary, Canada and Hefei, China conducted the first “real world” quantum teleportation. The two teams managed to teleport using their city’s existing fiberoptic cables.
The Calgary team managed to send photons over a distance of about 6.4 km (4 miles), at a fast rate of 17 photons per minute. The Hefei team, on the other hand, teleported photons at a slower rate, but over a 14-km (9-mile) stretch. The Hefei team also batted a 50% average in correctly determining the photon state of the particles after teleportation, due to an added, time-consuming step in the process. The Canadians scored about 25%.
Researcher Wolfgang Tittel at the University of Calgary in Alberta, Canada believes that their setup could be more useful in enabling quantum communication between cities using a quantum repeater. Jian-Wei Pan at the University of Science and Technology of China, researcher from the Hefei team, believe that what is needed is just a central quantum computer to make urban quantum teleportation work.
Both tests, undoubtedly, are achievements. Johannes Kofler at the Max Planck Institute of Quantum Optics in Munich notes that these “experiments can be seen as milestones on the path to a long-term goal, namely to build a fibre-based quantum internet connecting large cities.”
Quantum teleportation may also prove useful for a more secure data encryption. With entanglement, there would be no way for an outsider to read data moving along these quantum teleportation lanes. The findings of both teams were published in the journal Nature Photonics.