Future of quantum computing guided by old computer tech

Researchers have made a breakthrough in quantum technology development that has the potential to leave today’s supercomputers in the dust, opening the door to advances in fields including medicine, chemistry, cybersecurity and others that have been out of reach.

In a study published in the journal Nature on Wednesday, researchers from Simon Fraser University in British Columbia said they found a way to create quantum computing processors in silicon chips.

Principal investigator Stephanie Simmons said they illuminated tiny imperfections on the silicon chips with intense beams of light. The defects in the silicon chips act as a carrier of information, she said. While the rest of the chip transmits the light, the tiny defect reflects it back and turns into a messenger, she said.

There are many naturally occurring imperfections in silicon. Some of these imperfections can act as quantum bits, or qubits. Scientists call those kinds of imperfections spin qubits. Past research has shown that silicon can produce some of the most stable and long-lived qubits in the industry.

"These results unlock immediate opportunities to construct silicon-integrated, telecommunications-band quantum information networks," said the study.

Simmons, who is the university's Canada Research Chair in silicon quantum technologies, said the main challenge with quantum computing was being able to send information to and from qubits.

"People have worked with spin qubits, or defects, in silicon before," Simmons said. "And people have worked with photon qubits in silicon before. But nobody's brought them together like this."

Lead author Daniel Higginbottom called the breakthrough "immediately promising" because researchers achieved what was considered impossible by combining two known but parallel fields.

Silicon defects were extensively studied from the 1970s through the '90s while quantum physics has been researched for decades, said Higginbottom, who is a post-doctoral fellow at the university's physics department.

"For the longest time people didn't see any potential for optical technology in silicon defects. But we've really pioneered revisiting these and have found something with applications in quantum technology that's certainly remarkable."

Although in an embryonic stage, Simmons said quantum computing is the rock 'n' roll future of computers that can solve anything from simple algebra problems to complex pharmaceutical equations or formulas that unlock deep mysteries of space.

"We're going to be limited by our imaginations at this stage. What's really going to take off is really far outside our predictive capabilities as humans."

The advantage of using silicon chips is that they are widely available, understood and have a giant manufacturing base, she said.

"We can really get it working and we should be able to move more quickly and hopefully bring that capability mainstream much faster."

Some physicists predict quantum computers will become mainstream in about two decades, although Simmons said she thinks it will be much sooner.

In the 1950s, people thought the technology behind transistors was mainly going to be used for hearing aids, she said. No one then predicted that the physics behind a transistor could be applied to Facebook or Google, she added.

"So, we'll have to see how quantum technology plays out over decades in terms of what applications really do resonate with the public," she said. "But there is going to be a lot because people are creative, and these are fundamentally very powerful tools that we're unlocking."

This report by The Canadian Press was first published July 14, 2022.