One of the people working to link the globe through quantum networks is AWS research scientist Antia Lamas-Linares, the lead for the AWS Center for Quantum Networking.

Lamas-Linares and her team encode information in the quantum properties of photons, the fundamental units of light. By enciphering information, they are working to explore how to store, control, compute and transmit information in powerful ways that can’t be achieved through traditional computing and communication.

A challenge of quantum technology is successfully transmitting the carriers of quantum information — the photons — over long enough distances. Say someone wants to send photons with encoded quantum information over fiber-optic cable. The weakness of the quantum signal limits how far the photons can travel without being absorbed in the fiber.

One solution is a quantum repeater, which Lamas-Linares and others at AWS are developing as a step toward practical, long-distance quantum networks. Like a horse ready to embark on one leg of a Pony Express route, a repeater refreshes the delivery of the message, ensuring it arrives at its destination intact.

The development of a repeater is an exciting engineering challenge, Lamas-Linares said. For example, in a quantum network, photons travel through a fiber 1,000 times thinner than the width of a human hair. How do you perfectly align the fiber tip with the part of the repeater that receives the photon?

Nanopositioners are instruments that can nudge the fiber that fraction of a hair so that the photons successfully arrive in their tiny, high-tech depot. They’re a proven technology, but other factors need to be considered when planning for a large-scale information network.

“The technology definitely works. These nanopositioners are amazing, but it’s not a very scalable process,” Lamas-Linares said. ​“You wouldn’t want to have to operate a ton of them.”

Lamas-Linares and team are developing and testing different fabrication processes that will reliably convey the photons in and out of the repeater.

Complicating matters is the fact that their repeater technology operates in a refrigerator that’s a fraction of a degree above absolute zero. Once the repeater system is assembled, it will need to survive cycles of warming and cooling from close to absolute zero to room temperature. How do you accommodate the materials’ inevitable physical changes?

“When you cool down the device, it has to remain well-coupled, well-coordinated,” Lamas-Linares said. ​“Everything has to be extremely precise. It’s nanometer-scale positioning that needs to be exactly right.”

The challenge is emblematic of the kind of problem solving that industry is good at: the combination of small-scale engineering and large-scale production.

And it’s a good fit for Lamas-Linares, who came to AWS in 2021 with experience in both academia and industry. After earning her Ph.D. in physics from the University of Oxford and completing a postdoctoral appointment at the University of California, Santa Barbara, she moved to Singapore, where she co-founded the Centre for Quantum Technologies in 2003.

After two further stints at research centers in the United States, she joined a Singapore-based startup called SpeQtral as chief quantum scientist, working on quantum connections for small satellites.

At AWS, Lamas-Linares’ work combines the long-range perspective of academia with the consumer focus of industry.

“We’re in a privileged position because we are thinking about the customer needs, but we’re thinking long-term. Everybody here is aware that this is not like a 24-month life cycle. We work for a long-term vision,” she said. ​“If you’re in industry, you need a vision of where you want to arrive.”

She and others at AWS are exploring areas that will connect people through quantum technologies. For example, collaborators at AWS are interested in working with Q-NEXT’s university and DOE national laboratory scientists to create new quantum materials and devices using nanoscale fabrication techniques. They’re also interested in cooperating to make qubits — the fundamental units of quantum information — that are based on atomic-level irregularities in diamond.

AWS and Q-NEXT are also aligned in their interest to expand the pool of people who work in quantum information science.

“We always talk about the quantum scientists, but of course there is a lot more to building quantum systems than just knowing quantum science,” Lamas-Linares said. ​“We need electrical engineers, software experts, materials scientists and engineers — all these roles. It’s a very interesting area, and not just for people who are getting their Ph.D.s in quantum technologies. We particularly want to explore nontraditional routes for people coming into this field.”

Being part of Q-NEXT, she said, is an opportunity to recruit experts across disciplines, draw on the diffusion of techniques and information at different institutions, and break through the knowledge silos.

“As a global company that already provides computing resources to academia, industry and governments worldwide and boasts one of the world’s largest fiber networks, AWS will certainly play a role in building our future quantum infrastructure,” said Q-NEXT Director David Awschalom, who is also an Argonne senior scientist, vice dean of Research and Infrastructure and the Liew Family Professor of Molecular Engineering and physics at the University of Chicago, and the director of the Chicago Quantum Exchange. ​“Antia not only understands the physics and engineering challenges of quantum technology, but she also knows how to innovate for real-world challenges. She and others at AWS bring their long-range vision to Q-NEXT, and I’m excited to see what they’ll bring to the future of quantum communication.”

This work is supported by the U.S. DOE National Quantum Information Science Research Centers as part of the Q-NEXT center.