For the first time an international team of physicists succeeded to teleport information in a solid-state quantum memory, which is a prerequisite for future quantum internet.
In quantum teleportation no mass is transferred, but only the information that describes the state of the quantum system that transmits the signal. The other quantum system receives all the properties of the transmitted quantum state and creates an exact copy.
This kind of technology is behind a new generation of computer systems, including quantum Internet, which among other things promises to exchange information between computers in a completely secure way.
The new research developments took place at the University of Geneva where an international scientific team led by Felix Bussières used a crystal doped with rare earth ions as quantum memory and teleported information to it via a conventional means such as optical fiber.
One of the basic requirements for the teleportation of information is creating an entangled photon with a wavelength comparable to the diameter of the optical fiber. In quantum physics, the entangled particles are the pairs of particles whose quantum properties are interacting (and can be described by a common function), even when they are far apart.
Creating entangled photons with such strict requirements for wavelength was difficult enough for researchers, who nevertheless managed to produce such pairs, and even in two different infrared frequencies.
The information that was finally teleported was the polarization of a photon with a wavelength of 1338nm.
The signal traveled through an optical fiber 12 km long and was successfully transmitted by one quantum memory to another, and the subsequent measurements of the polarization of the photon-receiver were in exact accordance with those provided by the quantum theory.
This is another important step in quantum computing, which has begun to attract an ever growing research interest.