The concept of a global quantum internet is still in its infancy, but scientists believe it is possible, especially with the right equipment in space.
Now, for the first time ever, engineers from Singapore and the United Kingdom have tested a quantum satellite device and sent it into orbit, marking the first step towards the development of a global quantum network.
Experts from the University of Strathclyde and the National University of Singapore (NUS) dispatched the compact device known as SPEQS (Small Photon-Entangling Quantum System) into space.
SPEQS contains parts used in quantum communication and computing. Basically, it produces and measures pairs of photons or light particles.
Results from the recent test reveal that SPEQS does work — the device is creating photon pairs with connected properties. This indicates its efficient performance.
How It Works
The research team's first device is a technology pathfinder that takes photon from BluRay laser and then splits it into two. The device measures the photon pair's properties with the help of a laser diode, mirrors, crystals and photon detectors aligned in an aluminum block.
What This Means For The Future
Quantum entanglement is a link between quantum particles that would allow power in computing and security in communication. Albert Einstein once described it as "spooky action at a distance."
Scientists say producing correlated photons is the first step towards creating entangled photons.
Professor Artur Ekert, who had invented the idea of applying entangled particles for cryptography, says the findings of the new study are taking entanglement into the next level.
Ekert adds that the experiments will lead to more secure quantum communication and powerful quantum computation on a global level.
There are local quantum networks already in use, but the problem Singaporean and UK scientists wanted to solve was the limit set by distance.
Often, local quantum networks limit signals sent through the air at ground level to a few hundred kilometers.
Thanks to entangled photons, engineers may be able to beam them from satellites to connect points on the opposite side of the planet.
And although the photons still have to move through the atmosphere, the distance is only approximately equivalent to 10 kilometers at ground level.
What's Next?
While global quantum networks are still a few goals away, researchers have planned a series of roadmaps to get there. The next SPEQS sent to space is expected to produce entangled photons.
With later satellites, the team will work with CubeSat nanosatellites. A complete global quantum network would lead to a fleet of satellites into orbit and an array of stations at ground level.
Findings of the study are reported in the journal Physical Review Applied.
