Roadmap for space-based quantum internet

The quantum internet of the future could be upheld by small satellites known as cubesats. The past decade has seen remarkable advances in quantum technologies and already some demonstrations of quantum communication have been done from space.

Anwar et al. provide a critical look at what comes next for quantum communication in space. They delve into compact entangled photon-pair sources for satellites, discussing current cutting-edge technologies and challenges facing their development and wide spread usage for quantum key distribution (QKD).

“This paper gives a roadmap for the next 10 to 15 years,” said author Aitor Villar. “I hope that people find this as a good resource, whether they are brand new to the topic or if they already come with a little bit of knowledge.”

The paper lays out the roadmap by reviewing requirements for space-based QKD, potential designs for compact entangled photon-pair sources, and their specific technological challenges. While QKD devices currently exist, they are typically too bulky for cubesats and several engineering hurdles remain for them to be implemented from space. The authors suggest a synergy of engineering and quantum developments will help make space-based QKD a reality.

“The challenge is both from the quantum side and engineering side,” Villar said. “They need to be optimized in tandem.”

Once compact entangled photon-pair sources are further developed, the authors predict a global quantum network will soon emerge. This would help improve internet security and even help scientists study big unanswered questions about quantum mechanics, dark matter and gravitational waves.

Source: “Development of compact entangled photon-pair sources for satellites,” by Ali Anwar, Chithrabhanu Perumangatt, Aitor Villar, Alexander Lohrmann, and Alexander Ling, Applied Physics Letters (2022). The article can be accessed at https://doi.org/10.1063/5.0109702 .