Quantum Communication Demonstrated By Two Hovering Drones
The foundation stone for the quantum internet is being laid – in the air. Recently, researchers from Nanjing University in China showed that it is possible to send entangled photons between two drones named Alice and Bob that hover a kilometer apart.
This was done using an onboard laser and crystal to split a single photon into a pair of entangled photons, one sent to a ground station and the other sent to the other drone. Motorized devices on the drones ensured that the receivers and transmitters were aligned with each other.
Distance quantum communication between satellites and ground stations has been demonstrated before, which could lead to more quantum secure networks based on quantum encryption. However, this demo has shown that it can work between shorter distances even with comparatively cheap hardware. As New Scientist pointed out, this is the first time that such photon entanglement has been shown to work between two moving objects.
“This work demonstrates the optically relayed connection between mobile nodes, which we believe is a technology for future free space quantum communication with greater distance, less loss, and greater coverage,” said Zhenda Xie, professor at the School of Electronic Science at Nanjing University told Digital Trends. “It now offers a cost-effective new platform with exceptional flexibility and configurability. It can be a good compensation to close the gap between fiber optic and satellite quantum communication in order to realize a practical quantum network with full coverage in the future. “
While Xie said quantum communication is the most obvious use for a quantum network, it is nowhere near the only one. It could also be used for large area distributed quantum computations, more accurate timekeeping, basic physics experiments like quantum non-locality, and more.
“On the one hand, we plan to use the optical relay shown here to expand the scope of mobile quantum connections in the direction of a quantum network with complex topologies,” said Xie about the next step in the research. “With a local network size similar to this work, we can pack the quantum node smaller and larger [cost-effective] Drones for multi-user coverage, while it is also interesting to make large-scale quantum connections using high-altitude UAVs that are free from stray losses in the dusty, low-altitude air. In the long term, we also expect to connect this drone system with the existing fiber optic and satellite systems in order to achieve more comprehensive coverage in the global area. “
An article describing the work was recently published in Physical Review Letters.