A Quantum Leap Forward
With a new grant, a professor’s groundbreaking research takes on the internet
By Robert Emproto
As computer users, we’ve all experienced the frustration of Zoom calls dropping or encountered the dreaded buffer wheel as we try to move files, all because others in our home are using the Wi-Fi simultaneously. We hope that when we make online purchases that our saved credit card information is secure. And we can imagine that researcher in the Antarctic who needs gigabytes of data to download from multiple researchers across the world.
But what we might not be able to fathom is that what would normally take hours to download would take mere minutes with quantum internet — and that it would do so securely. The objectives of information that can travel faster than the speed of light and unhackable networks are within reach, thanks to groundbreaking research that has been taking place at Stony Brook University for the past decade in the lab of Eden Figueroa, associate professor and the quantum information technology research leader in the Department of Physics and Astronomy.
“I think the internet is one of the greatest things humanity has ever made. But it’s not perfect,” Figueroa said. “What we want is an internet that’s fast and secure. Those are the two questions that there are currently no answers to.”
That’s where his research fits in.
Figueroa, who has long been fascinated with quantum mechanics, came to SBU in 2013, the first professor hired specifically to do quantum information science, tasked with building both a lab and a program. A decade later, Figueroa and his team of graduate students and undergrads aim to develop and implement the first agnostic quantum repeater network.
While a standard computer handles digital bits of 0s and 1s, quantum computers use quantum bits that can take on any value between 0 and 1. And if you entangle the bits, you can solve problems that typical computers cannot. Figueroa said the main challenge to building quantum networks is demonstrating that they work with single photons and showing you can transfer entanglement in a network, using it whenever you need.
“If you have entanglement, you have quantum teleportation, and therefore you can move information from one place to the other,” he said. “If you manage to have lots of photons that are all entangled, then you can — in principle, using quantum teleportation — transfer lots of data from one place to the other. Once we get that far, the challenge is to transfer these entangled photons over longer distances.”
He added that all the technology his team develops in the laboratory is intended to create a first version of that quantum repeater.
The test bed for his ideas lies in a quantum network connecting locations in Stony Brook and Brookhaven National Laboratory (BNL), about 17 miles away. Figueroa used existing fiberoptic infrastructure and has deployed entanglement sources and quantum memories in several buildings on the BNL campus, with fibers used to quantum-connect the physics and instrumentation buildings with the Scientific Data and Computation Center. A similar local area quantum network was developed on the Stony Brook campus.
With the quantum communication channels in place, Figueroa uses the photonic entanglement sources to store and retrieve quantum correlations simultaneously in four quantum memories on both campuses. In 2020, the team achieved transmission of single-photon-level polarization quantum bits (qubits) in a configuration covering a total of approximately 87 miles. This marked the longest successful quantum communication link experiment in the United States.
“In the last two or three years, the problem has become bigger,” said Figueroa. “Now we have some ‘toys’; how do we network them? This is what makes us unique. With these test beds we are really testing the devices in this network configuration, and really moving quantum information over longer distances. That is very original. In the U.S., there are only a few test beds, but I think the one that we have is by far the most advanced right now.”
The project took a leap forward in November 2022 thanks to a $6.5 million grant from the Long Island Investment Fund awarded to SBU to construct the new Long Island Quantum Internet Test Bed. It’s part of $46.5 million in grants for three regional projects announced by New York State Governor Kathy Hochul. The $350 million Long Island Investment Fund focuses on projects that will support and grow the regional economy, enhance communities and have lasting economic impacts across Long Island. Additionally, President Maurie McInnis has dedicated $12M of Presidential Innovation and Excellence Funds to grow Stony Brook’s quantum information technology research. A portion of those funds will support Professor Figueroa’s work.
As a flagship institution, we recognize building the Quantum Internet is among the most critical technological frontiers of our time. Stony Brook University and Brookhaven National Laboratory are internationally recognized leaders in this field, with the vision and scientific expertise to ensure that New York State is at the forefront of this work.
— Maurie McInnis, President
As a result, the university, in collaboration with BNL, will construct the new $13 million Quantum Internet Test Bed. It will be a network of five nodes that are physically connected using optical fiber. It will be overseen by the Long Island Quantum Internet Center, located at Stony Brook and in partnership with BNL.
The center will help Figueroa and his team catalyze new technologies to meet his dreams of accelerating today’s internet functionality, improving the security of our communications and enabling dramatic advances in computing. And it will grow to include other New York State universities, laboratories and industry partners with research teams dedicated to investigating and implementing the new applications of quantum technology in the context of telecommunications and the internet. The project will establish Long Island as a global hub of quantum internet technology development — with SBU and BNL at the center — and bring together researchers, educators and investors in a collaborative effort to accelerate the commercialization of quantum internet technologies. Ultimately, this project will make our home computers faster and safer as well.