An international team of researchers from Austria, Canada, Germany and Norway has used ESA’s Optical Ground Station at the Teide Observatory in Tenerife to establish anew distance record in quantum teleportation, reproducing the characteristics of a particle of light at 143 kilometers.
Quantum teleportation is not about copying, in the strictest sense of the term, since the act of transferring information from one particle to another destroys the original particle: its characteristics are transferred to the entangled particle. In the new experiment, scientists have managed to transfer the physical properties of a light particle (a photon) to another particle by quantum teleportation, thus establishing a link that covers the 143 km that separate the Jacobus Kapteyn telescope, on the Canary Island of La Palma, and the ESA Optical Ground Station in Tenerife. Both particles must first “entangle”. Once this is done, the measurement of a certain physical property, such as polarization or spin, will generate the same result in both particles, regardless of how far apart they are and without any other signal being physically transferred between them. The results of the experiment were published this week in the scientific journal Nature.
“This achievement paves the way for long-distance quantum communications,” explained Eric Wille, project supervisor for ESA.. “The first quantum teleportation took place under laboratory conditions. The challenge here has been to keep the entanglement between the two photons at a distance of 143 km, despite the disturbances of atmospheric conditions.” Very sensitive photon detectors were installed for the experiment, and the clocks at the source and destination stations were synchronized with a precision of 3,000 millionths of a second. With the latter, the researchers ensured that the correct photons were detected – the maximum precision provided by the GPS signal is 10,000 millionths of a second. The two telescopes are located in volcanic terrain, 2,400 meters high, and must cope with harsh weather conditions for these types of measurements, such as wind, rain, snow and dust storms.
Albert Einstein referred to the phenomenon of quantum entanglement as a “spooky action from a distance“But it is a fundamental and documented physical phenomenon in a future generation of ultra-powerful computers, based on the teleportation of quantum bits or qubits. It is also essential in inviolable encrypted communication systems.
“The next step will be to achieve teleportation with a satellite in orbit, to demonstrate that quantum communication is possible on a global scaleRupert Ursin of the Austrian Academy of Sciences has announced.
