Energy Department unveils plans for a quantum internet
A new report identifies the scientific applications, priority research directions and key milestones that must be achieved to design and construct “the ultimate in secure communications.”
The Department of Energy unveiled a blueprint for a nationwide quantum internet that builds on the research and resources at the national labs in molecular engineering, quantum information science, high-performance computing and advanced networking.
“From Long-distance Entanglement to Building a Nationwide Quantum Internet: Report of the DOE Quantum Internet Blueprint Workshop,” came out of a February 2020 workshop to develop the strategy for a national quantum internet, describing the essential research required, the engineering and design barriers, near-term goals. The report identifies the scientific applications, priority research directions and key milestones that must be achieved to design and construct eventual national quantum internet.
Near term, a quantum internet could be used to improve measurements of gravitational waves, enhance images from telescopes, improve sensor networks and connect quantum computing systems to each other and to classical systems. Delivering “the ultimate in secure communications,” however, is a central application, the report said. A quantum network’s ability to exchange information and detect any interception could help secure national security, banking, aircraft communications and energy delivery infrastructure as well as health services, elections and gaming.
Because the technology is expected to have a major impact on large-scale sensing experiments, it is especially applicable to astronomy, materials discovery and life sciences -- key mission areas for DOE, which has been conducting quantum network research and is now ready to move from small-scale experiments toward “a first nationwide quantum Internet facility,” the report said.
The report lays out crucial research objectives, including building and then integrating quantum networking devices, perpetuating and routing quantum information and correcting errors, DOE officials said in announcement of the blueprint. Technology milestones include verifying secure quantum protocols over existing fiber networks and sending entangled information across increasingly longer distances.
Quantum computing faces significant challenges. Signals decay over even relatively short distances, necessitating some kind of repeater infrastructure to scale the network to internet size. Transmitting quantum bits from satellites offers another option. In 2019, China established satellite-enabled photon entanglement over a distance of 1,200 km, a technique that is estimated to be 12 orders of magnitude beyond what a fiber link would allow, the report said. These “free-space links” may enable a possible bridge between local fiber-based quantum networks, allowing construction of transcontinental or transatlantic quantum networks.
Designing a quantum internet will also “require developing a new quantum-updated version of the network stack,” the report said, including optical interfaces, satellite-to-fiber connections and high-speed, low-loss quantum switches. Other issues to be addressed include integrating multiple quantum networking devices and adapting the switching, routing and error correction used in classical networking for quantum particles traveling over long distances.
The blueprint’s milestones start with building a prototype quantum internet on fiber networks where users simply receive and measure quantum states, as has already been demonstrated. Researchers from Oak Ridge and Los Alamos National Laboratories worked with EPB, a Tennessee utility and telecommunications company, to show how quantum key distribution could secure and sync communication among the nation’s electricity suppliers. For the demonstration, Oak Ridge and Los Alamos researchers generated separate keys using different methods that, when interfaced at a trusted node, generated a third key, which was then distributed between the Los Alamos and Oak Ridge systems.
The next step would be moving to an intercampus or intercity network and eventually to networks that cross state lines and link laboratories, universities and industry. Progress has been made there too.
The Illinois-Express Quantum Network consists of multiple quantum nodes dispersed in the Chicago area that can perform the kind of quantum measurements that would be useful in sensor networks. Argonne National Laboratory, a partner in the effort, created a 52-mile quantum loop entanglement distribution network that will soon be connected to the Fermi National Accelerator Laboratory, establishing a three-node, 80-mile testbed for quantum communication.
A New-York-based effort led by Stony Brook University and Brookhaven National Laboratory has explored constructing the infrastructure for a quantum Internet prototype that runs across the state over the existing fiber infrastructure of ESnet, the DOE’s high-performance, unclassified network built to support scientific research. The 80-mile quantum network testbed uses a chain of quantum repeaters, extended across Long Island via three entangled sources, six quantum memories and two entanglement swapping stations.
The blueprint provides a pathway to ensure the development of the National Quantum Initiative Act, which was signed into law by President Trump in December of 2018, DOE officials said.
“This work entails defining and building entirely new fields of study, and with them, new frontiers for technological applications that can improve the quality of life for many around the world and support the long-term competitiveness of our city, state, and nation,” said Robert J. Zimmer, president of the University of Chicago.