OAK RIDGE, Tenn., Oct. 23, 2019—A joint research team from Google Inc., NASA Ames Research Center, and the Department of Energy’s Oak Ridge National Laboratory has demonstrated that a quantum computer can outperform a classical computer at certain tasks, a feat known as quantum supremacy.

Quantum computers use the laws of quantum mechanics and units known as qubits to greatly increase the threshold at which information can be transmitted and processed. Whereas traditional “bits” have a value of either 0 or 1, qubits are encoded with values of both 0 and 1, or any combination thereof, allowing for a vast number of possibilities for storing data.

While still in their early stages, quantum systems have the potential to be exponentially more powerful than today’s leading classical computing systems and promise to revolutionize research in materials, chemistry, high-energy physics, and across the scientific spectrum. The team’s results, published today in Nature, provide a proof of concept for quantum supremacy and establish a baseline comparison of time-to-solution and energy consumption.

“This achievement of quantum supremacy is a testament to the strength of American innovation, and DOE’s Labs are helping lead the way in this groundbreaking area of research,” DOE Under Secretary for Science Paul Dabbar said. “The mastery of quantum technology is creating a new Information Age that offers new ways to process information to benefit science and society.”

In this case the quantum computer, built by Google and dubbed Sycamore, consisted of 53 qubits. The classical computer was ORNL’s Summit, housed at the Oak Ridge Leadership Computing Facility (OLCF) and ranked as the world’s most powerful thanks to its more than 4,600 compute nodes.

Both systems performed a task known as random circuit sampling (RCS), designed specifically to measure the performance of quantum devices such as Sycamore. The simulations took 200 seconds on the quantum computer; after running the same simulations on Summit the team extrapolated that the calculations would have taken the world’s most powerful system more than 10,000 years to complete with current state-of-the-art algorithms, providing experimental evidence of quantum supremacy and critical information for the design of future quantum computers. Not only was Sycamore faster than its classical counterpart, but it was also approximately 10 million times more energy efficient.

The researchers also estimated the performance of individual components to accurately predict the performance of the entire Sycamore device, demonstrating that quantum information behaves consistently as it is scaled up—a necessary property for the design of large-scale quantum computers.