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Newswise — The concept of quantum is popping up everywhere these days, from the Marvel Cinematic Universe to "Everything Everywhere All at Once." But what exactly does quantum mean? And what impact will it have in our multiverse? 

For World Quantum Day on April 14, and in celebration of the United Nations designating 2025 as the International Year of Quantum Science and Technology, Virginia Tech quantum experts , , and share what quantum computers can do now, what they’re poised to do in the future, and why this cutting-edge research matters.

What does "quantum" mean?

In a sentence, “quantum mechanics is the theory that explains the behavior of matter and light at microscopic scales,” said Economou, professor and the T. Marshall Hahn Chair of Physics in the .

But the exact behavior of a quantum object like an electron or a photon is not always predictable, said Cao, assistant professor of physics.

“It’s like babysitting a super kid. Think a wilder version of Jack-Jack from the movie 'The Incredibles.' The moment you take your eyes off him, he’s in a million different places at the same time. Despite all this craziness, there is still hope to babysit him because his behaviors follow a pattern that can be used to predict where he can be found when observed.” 

What can quantum computers actually do?

A quantum computer is a machine that uses the “superpower” of quantum behavior to process information in a fundamentally different way from today’s computers. 

They’re not automatically faster at everything, but “they are good at particular applications, for example, quickly solving certain mathematical problems that would take your laptop millions of years to solve,” Economou said.

Instead, “they’ll help us study and resolve fundamental science questions in physics, chemistry, and biology as well as technological challenges in health care, communication systems, advanced materials, and national security,” said Scales, the J. Byron Maupin Professor of electrical and computer engineering in the .

A quantum computer also can crack encryption at rates unmatched by any existing computer. That makes it a national security issue.

What’s the timeline for quantum computers to become a thing?

Don’t expect to have a quantum computer as a laptop in the future. These days, you’ll find quantum computers in the research lab, where they’re still small and error prone. 

But they’re getting better all the time. “Advances are continually being made toward making practical commercial quantum computers a reality,” said Scales. “Much of the promise is to come within the next decade or so. That's why there is so much emphasis now.” 

“Current indications are optimistic,” said Cao. “If I have to make a bet, I would say about 20 to 50 years before quantum computers become powerful enough to have a significant impact in our lives. But you never know.”

Is this as hard as everyone thinks it is?

In a word, yes, said Economou. “It is an extremely difficult technology to build. Quantum information is fragile, it just dies quickly.” The researchers are trying to come up with a range of ways — better engineering, better control, better quantum error correction — to keep it alive.

To Cao, the hardest part may be getting experts in different areas to cooperate on building these machines. “Making a working quantum computer that can outperform classical computers is very much a grand challenge for scientists and engineers alike, as remarkable as building the Large Hadron Collider.”

About Charles Cao
is an assistant professor of physics and a member of the Virginia Tech Center for Quantum Information Science and Engineering.

About Sophia Economou
is a professor of physics and the T. Marshall Hahn Chair in Physics. She directs the Virginia Tech Center for Quantum Information Science and Engineering

About Wayne Scales
is the J. Byron Maupin Professor of Engineering in the Bradley Department of Electrical and Computer Engineering.