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Alumnus Andrew Yao Sees Quantum Computing as the Next Great Science

7/20/2016 3:59:00 PM Laura Schmitt, CS @ ILLINOIS

A highlight of the CS @ ILLINOIS Alumni Awards weekend was a keynote address by alumnus Andrew Chi-Chih Yao (PhD ’75). Yao is the recipient of the 2000 A.M. Turing Award, considered the Nobel Prize of computing, for his groundbreaking contributions to the theory of computation. Yao spoke on October 23 to several hundred faculty, alumni, and students about what quantum computing is and why it’s such a potentially promising field.

“I think quantum computing is for real,” said Yao, describing the technology that exploits the properties of quantum mechanics and that could lead to computers much more powerful than today’s supercomputers. In fact, Yao said, 20 years from now we’ll look back on quantum computing and see it as the start of one of the great sciences.

To make his case, Yao gave two examples of important scientific achievements that enabled major advances in other fields. The first was the discovery of x-ray crystallography in 1895 by Wilhelm Conrad Röntgen, which led to a series of discoveries during the 20th century, such as x-ray diffraction and the analysis of atomic structures, as well as the discovery of the double helix.

“X-ray crystallography really enabled us to explore things that previously could not have been done,” said Yao, noting its impact on the fields of physics, biology, and medicine. “This is definitely great science.”

Yao’s second example of great science began with German mathematician David Hilbert’s decision problem, which led to Alan Turing’s invention of the Turing machine in 1936. “Hilbert’s idea got people to think about the critical question of what is computation,” Yao said.  “Alan Turing was thinking about this problem when he invented the Turing machine model.”

Fast computing machines weren’t feasible, though, until after World War II when John Bardeen—who later became a faculty member at Illinois—co-invented the transistor at Bell Labs in 1947. “The rest is history for all of us,” said Yao, noting how computers pervade every profession and are critical to every scientific, engineering, and humanities discipline. “With this form of success, computer science definitely qualifies as a great science.”

According to Yao, quantum computing is the descendent of x-ray crystallography and computer science. “Quantum computing can be a great science, too,” he said. “It has an excellent blue-blood pedigree.”

Yao noted that Moore’s law will eventually come to an end and that scientists and engineers cannot avoid the quantum effect. Two scientists in particular have helped explain and exploit the quantum phenomenon through their groundbreaking research, which has done much to make quantum computing a reality.

David Wineland, who won the 2012 Nobel Prize in Physics, captured electrically charged atoms, or ions, in a kind of trap and studied their interactions with photons.  This ion trap technology, which is the basis for qubits, Yao said, is the most advanced quantum computing technology available.


Dr. Yao answered several questions from the audience following his keynote address.
Dr. Yao answered several questions from the audience following his keynote address.

Peter Shor not only designed an efficient quantum algorithm for factoring large integers but also theoretically solved the coherence problem. “So it’s possible to do error correction in the quantum case,” said Yao, noting that physicists originally thought it was impossible to do error correcting.

Yao’s own interest in quantum computing began in the early 1990s, while he was a faculty member at Princeton. Today, Yao is the dean of the Institute for Interdisciplinary Information Sciences at Tsinghua University in China, where he runs the Quantum Network Project.

“If it’s feasible, it’s going to be done,” Yao said, because large organizations like Microsoft, NIST, and universities around the world are investing in the technology. “Quantum computing will pay off sooner than many people believe.”

Watch a video of Dr. Yao's keynote address.