Experiments on transfer of quantum states of photons in free space at a distance of 16 km successfully carried out physics from the University of Science and Technology of China (USTC) and Tsinghua University (Tsinghua).
In the experiment had been used well-known scheme with three photons A, B and C. And the sender and receiver are issued photons C and D of the confusing pair – in this case the sender, which also has a particle A, to measure the system speakers, because of what the initial state And destroyed. The results of measurements are sent via a standard channel receiver, which performs the necessary transformation on the particle B and restores the original state A.
As a result of efforts of scientists, “quantum channel” connected Badaling, located east of Beijing, 75 kilometers away, and Huaylay, Hebei province. Sami pairs of entangled photons, one of which went to the distance of 16 miles, got by the method of spontaneous parametric scattering, using the crystal beta-barium borate (BBO).
According to a report published by Nature Photonics, calculated based on the experience of reliability index for the transfer of quantum state is equal to 89%.
This is not the first exciting experience of Chinese with quantum teleportation – and conducted such experiments, especially for the development of quantum cryptography.