QTS - Quantum Teleportation in Space
The Space-QUEST (Quantum Entanglement for Space Experiments) mission will involve quantum experiments in space in the future. Objectives for the Space-QUEST experiments include demonstrating fundamental quantum physics principles beyond the distance capabilities on Earth as well as absolutely secure quantum key distribution from space to ground.
Specifically, we planned to perform a proof-of-principle experiment for free- space quantum teleportation over long distances. Since the long term objective was to perform the teleportation of a given unknown quantum state from a ground station to a satellite we investigated the performance of teleportation over a 144 km long free space transmission path between the Canary Islands of La Palma and Tenerife in an intermediate step.
First, the requirements for the teleportation system to be utilized in harsh real-world conditions were investigated theoretically. Based on the results, a suitable setup was designed and developed in the shielded laboratory, where the performance of the whole system was tested in detail at the component level. After the successful performance verification phase, the complete teleportation system was disassembled, shipped to the Canary Islands and again set up for performing the proof-of- principle field experiment in a realistic setting over a 144 km free-space path.
Finally, we were able to teleport a series of four different input states from La Palma to Tenerife. The obtained results showed a teleportation quality which was well above the limit that could be achieved by classical means. Our work explored the limits for ground-based free-space quantum teleportation, and our setup was able to cope with the optical link attenuation expected for a quantum transmission from a ground-based transmitter to a Low Earth Orbiting (LEO) satellite receiver.
This experiment represented a crucial step towards future quantum networks in space. The technology involved has reached maturity and is set to play a key role in a new era of fascinating experiments.
Austrian Academy of Sciences, Institute for Quantum Optics and Quantum Information (IQOQI) - Rupert Ursin