Quantum teleportation, the act of reconstructing quantum data somewhere else, is impressive just by itself. However, scientists at the US’ National Institute of Standards and Technology have managed to one-up that feat. They’ve broken the distance record for quantum teleportation by transferring the information from one photon to another across 63 miles of optical fiber. That may not sound like much, but it’s an achievement just to beam that data in the first place — 99 percent of photons would never make the complete trip. It was only possible thanks to newer detectors that could pick up the faint signal of the lone light particle.
Many scientists now believe that once teleportation of people from one place to another will be possible. However, at present and for quite long time, we will be limited to teleportation of quantum information.
The evolution of this research will contribute to the creation of quantum Internet, which will interconnect lightning-fast quantum computers. Before the idea of quantum internet is realized, quantum teleportation will make data transfer more secure than in today’s communications, as the transmission of quantum data is considered 100% secure (at least theoretically).
By trapping atoms at the distance of about 200nm from a 500nm-in-diameter glass fibre, strong interaction between light and atoms can be implemented. The two systems are then able to exchange quantum information – a process that forms a basis for possible future technologies such as quantum cryptography or quantum teleportation.
One of the biggest challenges of quantum mechanics so far has been in efficient storing and subsequent retrieving of information. The method developed in Vienna offers a convenient solution.
“Our setup is directly connected to a standard optical glass fibre that is nowadays routinely used for the transmission of data”, Rauschenbeutel said. “It will therefore be easy to integrate our quantum-glass-fibre cables into existing fibre communication networks.”
The team has also managed to improve the duration of the period for which the atoms can stay entangled. So far, researchers have been observing that after some time, quantum information is lost as the atoms are affected by the so called ‘decoherence’.
“Using some tricks, we were able to extend the coherence time of the atoms to several milliseconds, in spite of their small distance to the fibre surface”, Rauschenbeutel explained.
The study was conducted by researchers led by Professor Ronald Hanson of the Institute of Nanoscience Delft University of Technology in the Netherlands. They managed to teleport information encoded in subatomic particles between two points spaced three meters apart from each other with 100% accuracy. Teleportation is based on the mysterious phenomenon of quantum entanglement, in which the state of a particle automatically affects the state of another distant particle.
You’d clearly need to send much more information before this teleportation becomes practical, but the achievement does open the door to many possibilities in quantum computing. You could use unbreakable quantum encryption at inter-city distances, for instance. The biggest challenge may simply be to extend the range to the point where quantum data transfers work on the scale of the internet, where there are occasionally thousands of miles between connections.