SUNY collaboration explores quantum computing network

BUFFALO, N.Y. — Across the globe, scientists are racing to create practical quantum computers. Such an advancement would eclipse the capabilities of today’s supercomputers, potentially unlocking solutions to society’s most vexing problems such as disease and climate change.

At the same time, scientists are studying what components — such as light sources, detectors and beam splitters — are needed to create efficient quantum computing networks.

To further each effort, a State University of New York (SUNY) research team has used open-source software to simulate a functioning quantum computing network. The study, “Entanglement generation in a quantum network with finite quantum memory lifetime,” was published online March 8 in AVS Quantum Science.

“The potential of quantum computing is enormous,” says the study’s lead author Vasili Perebeinos, PhD, professor of electrical engineering in the University at Buffalo School of Engineering and Applied Sciences. “And while we’re moving closer to the adoption of this new technology, there are still many fundamental questions that need to be answered.”

Unlike today’s computers, which code information in bits that take the value of “1” or “0,” quantum computers use quantum bits (also called qubits) that harness the ability of subatomic particles to exist in both the “1” and “0” state simultaneously. This code shift dramatically increases a computer’s power to analyze information.

However, most qubits are very fragile. Some require temperatures as low as -273 degrees Celsius to exhibit “long-lifetime coherence,” which is another way of saying the qubits continue to properly function, allowing the computers to perform their work.

The new study aims to explore these limitations by simulating a quantum computing network where two parties share information securely.

This includes numerous aspects of quantum science, including quantum entanglement, which, according to Merriam-Webster, is “a property of a set of subatomic particles whereby a quantum characteristic (such as spin or momentum) of one particle is directly and immediately correlated with the equivalent characteristic of the others regardless of separation in space.”

The goal, researchers say, is to improve the scientific community’s knowledge on the types of physical systems needed to make quantum computing networks reliable and practical.

“We want to explore how efficiently we can share quantum entanglement between distant nodes,” says co-author Xuedong Hu, PhD, professor of physics in the UB College of Arts and Sciences. “The essential criterion for effective quantum internet is generating entanglement robustly among distant nodes with a high repetition rate.”

For the simulations, the researchers used technology developed by Argonne National Laboratory.

“The simulations of the quantum network performance as a function of hardware components characteristics opens an avenue for examining the usefulness of different materials platforms to design circuit elements in the quantum network,” Perebeinos says. “For example, a scalable second-generation quantum local area network is desirable to be based on solid-state material platforms. However, long-lifetime quantum memory in solid-state materials is more challenging than in quantum memory based on atomic vapors.”

The research is ongoing, with further simulations planned.

Additional co-authors include Eden Figueroa, PhD, associate professor in the Department of Physics and Astronomy at Stony Brook University, and Vyacheslav Semenenko, who was a postdoctoral researcher in Perebeinos’ lab from 2019-21.

The Office of the Vice President for Research and Economic Development at UB and SUNY Research Seed Grant Program provided funding to support the study.