The researchers developed a miniaturized source of quantum entanglement that measures just 20 by 10 centimeters. Credit: Center for Quantum Technologies, National University of Singapore.
In a critical step toward creating a global quantum communications network, researchers have generated and detected quantum entanglements aboard a CubeSat nano-satellite that weighs less than 2.6 kilograms and is in orbit around Earth.
“In the future, our system could be part of a global quantum network that transmits quantum signals to receivers on Earth or to other spacecraft,” said lead author Aitor Villar of the Center for Quantum Technologies at the National University of Singapore. “These signals could be used to implement any type of quantum communication application, from quantum key distribution for extremely secure data transmission to quantum teleportation, where information is transferred by replicating the state of a quantum system remotely.”
In Optics, The magazine of the Optical Society (OSA) for high-impact research, Villar and an international group of researchers demonstrate that their miniaturized source of quantum entanglement can successfully operate in space aboard a low-cost and cost-effective CubeSat that it is smaller than a shoe box. CubeSats are a standard type of nanosatellite made from multiples of cubic units of 10 cm × 10 cm × 10 cm.
“Progress towards a global space-based quantum network is occurring at a rapid rate,” Villar said. “We hope that our work will inspire the next wave of space-based quantum technology missions and that new applications and technologies can benefit from our experimental findings.”
Quantum miniaturizing tangle
The phenomenon of quantum mechanics known as entanglement is essential for many quantum communication applications. However, the creation of a global network for the distribution of tangles is not possible with optical fibers due to the optical losses that occur over long distances. Equipping standardized small satellites in space with quantum instrumentation is one way to tackle this challenge cost-effectively.
As a first step, the researchers had to demonstrate that a miniature photon source for quantum entanglement could remain intact through the stress of launch and successfully operate in the harsh environment of space within a satellite that can provide minimal energy. To accomplish this, they exhaustively examined each component of the photon pair source used to generate quantum entanglement to see if it could be made smaller or more resistant.
SpooQy-1 CubeSat contains a miniaturized quantum instrument that creates pairs of photons with the entangling quantum property. The entanglement is detected in correlations of the polarizations of the photons. Credit: Center for Quantum Technologies, National University of Singapore and NASA.
“At each stage of development, we were actively aware of budgets for mass, size, and power,” Villar said. “By iterating the design through prototyping and rapid testing, we arrived at a robust small form factor package for all the out-of-the-box components required for a tangled photon pair source.”
The new source of miniaturized photon pairs consists of a blue laser diode that shines on nonlinear crystals to create photon pairs. Achieving high-quality tangles required a complete redesign of the frames that align the nonlinear lenses with high precision and stability.
Launch into orbit
The researchers rated their new instrument for space by testing its ability to resist vibration and thermal changes experienced during a rocket launch and operation in space. The photon pair source maintained very high quality entanglement throughout the test, and crystal alignment was maintained even after repeated temperature cycles of -10 ° C to 40 ° C.
The researchers incorporated their new instrument into SpooQy-1, a CubeSat that was deployed into orbit from the International Space Station on June 17, 2019. The instrument successfully generated pairs of entangled photons at temperatures of 16 ° C to 21.5 ° C.
“This demonstration showed that miniature tangle technology can work well while consuming little energy,” Villar said. “This is an important step towards a cost-effective approach to deploying satellite constellations that can serve global quantum networks.” The project was funded by the Singapore National Research Foundation.
The researchers are now working with RALSpace in the UK to design and build a SpooQy-1-like quantum nano-satellite with the capabilities necessary to transmit entangled photons from space to a terrestrial receiver. This is slated for the onboard demonstration of a 2022 mission. They are also collaborating with other teams to improve CubeSats’ ability to support quantum networks.
Quantum cryptographic keys for secure communication distributed 1,000 kilometers further than previous attempts
Aitor Villar et al, Demonstration of entanglement on board the satellite year, Optics (2020). DOI: 10.1364 / OPTICA.387306
Provided by The Optical Society
Citation: Quantum entanglement demonstrated aboard CubeSat in orbit (June 25, 2020) recovered on June 25, 2020 from https://phys.org/news/2020-06-quantum-entanglement-aboard-orbiting-cubesat.html
This document is subject to copyright. Other than fair dealing for private research or study purposes, no part may be reproduced without written permission. The content is provided for informational purposes only.
