The U.S. government is turning to quantum computing, a cutting-edge technology that harnesses the power of quantum mechanics, in an effort to beat China as the world leader in supercomputing.

Quantum computing could be integrated into an extremely powerful “exascale” supercomputer, which the U.S. has been formally working to build since 2015, according to the Department of Energy. The department recently announced it would award $258 million in grants toward making headway in the exascale project.

An exascale system is capable of performing one quintillion — or a billion billion — calculations per second. By 2021, the U.S. has said it plans to deliver at least one exascale supercomputing system, while China has said it plans to deploy its first system by 2020, the WSJ has previously reported. China currently holds the top two spots in a twice-yearly worldwide ranking of 500 fastest scientific computers, while the U.S. comes in fourth after Switzerland.

The most powerful supercomputer in the U.S. today is the Titan, built by Cray Inc., which can handle 17,590 trillion calculations per second. An exascale supercomputer could crunch data at least 50 times faster than that.

Quantum computing, as well as neuromorphic computing, in which sophisticated artificial intelligence computing systems are modeled after the human brain, could be integral in the race to build an exascale supercomputer, said Jeff Nichols, associate laboratory director of computing and computational sciences at the Department of Energy’s Oak Ridge National Laboratory.

The accelerator technologies of today are types of technologies within supercomputers such as graphics processing units that are used alongside traditional computer processing units to perform powerful calculations, specifically related to machine learning, Dr. Nichols said. In a few years, those accelerator technologies could include quantum and neuromorphic computing, he said.

The chip pictured above powers D-Wave's 2000Q quantum computer. Photo: The chip pictured above powers D-Wave's 2000Q quantum computer.

“These types of accelerators are going to give us the opportunity to be leaders in the field of supercomputers … it’s so important to national security and economic competitiveness,” Dr. Nichols said. “We can’t afford to cede that to China.”

Quantum computing has the potential to sort through a vast number of possibilities within a fraction of a second to come up with a probable solution. This is possible through the use of quantum binary digits, or qubits, which represent and store information in both 0s and 1s simultaneously, compared to binary digits, or bits, which can either be 0s or 1s and have dominated the computing industry to date. The cutting-edge science harnesses the power of quantum mechanics and is making rapid advances, with technology titans such as Alphabet Inc.’s Google researching its potential.

Dozens of researchers at Oak Ridge began experimenting earlier this month with a quantum computer, over the cloud, made by D-Wave Systems Inc. Oak Ridge and D-Wave announced their partnership Tuesday. The Oak Ridge researchers include physicists, computational material sciences experts and mathematicians. The national laboratory houses several of the world’s top supercomputers, including Titan.

Though it’s still early to predict, quantum processors within an exascale supercomputer could be particularly useful for solving problems related to astrophysics, nuclear energy, cybersecurity and computational climate modeling, Dr. Nichols said. For example, Oak Ridge researchers could investigate how quantum computing could be used to help protect the energy grid from cyber attacks, he said. “D-Wave opens up a whole realm of possibilities,” he said.

Quantum computing in other sectors has previously shown its capacity to speed up drug discoveries and optimize traffic flow in cities.

The Department of Energy in June said it would award $258 million over three years to be shared by six tech companies, as part of a plan to develop new supercomputers that can crunch data at least 50 times faster than the nation’s most powerful systems today, the WSJ previously reported.

China has also been experimenting with quantum technology, and recently succeeded in sending specially linked pairs of light particles from space to Earth, in an effort that could eventually result in an “unhackable” global communications network.