The central tenet of quantum mechanics, the study of uncertainty, is that the state of a system can never be fully known. But the drive to explain the uncertainties of the world is exactly what motivates professor Aephraim Steinberg of U of T’s department of physics.
“Quantum mechanics is the theory of everything in the universe,” said Steinberg. Though QM deals with how subatomic particles work, existing both as a wave and a particle, the applications of the theory to communication and computer technology is immense.
A major part of Steinberg’s work has be applied to the growing field of quantum information processing, changing how we store and convey bits and bytes of information like a computer. A quantum computer would use a language much like the binary language of a classical computer, but with higher efficiency. Problems based on the factorization of large numbers may take decades to solve on a classical computer, but would be quick work for a quantum computer. Although a quantum computer could process information faster than current computers, it is still unknown whether a solution to complex problems like factorization could ever be found in a reasonable time.
“It could take a million years or microseconds to solve the problem,” said Steinberg.
The first step towards a quantum computer is to understand the unpredictable behaviour of quantum particles, such as the quantum tunneling effect. When a ball rolls up a hill, it requires sufficient speed and energy to push it. In quantum terms, none of these rules apply. Instead, a quantum particle can behave like a wave and appear on the other side of the hill, as if it has tunneled right through.
“I think the wave function describes what’s really out there,” said Steinberg. “What you or I actually see or observe, these ‘measurements,’ are much less a total description of reality as a description of the particular way our universe evolved and the way we evolved to interact with things.”
Phenomena like tunneling are problems Steinberg has approached by cooling atoms down to temperatures nearing absolute zero, though his research is not limited to this method. The study of ultra-cold atoms is in its infancy, but Steinberg believes the role these atoms will play in the future of quantum mechanics will be akin to the innovations in optics research propelled by the laser in the last 40 years.
“It is a noble goal of physics to try unify as much of nature as we can,” said Steinberg. “Although we don’t particularly understand why the world should be so unified … we do understand the world better when we look for these kind of elegant unified theories.”
Steinberg’s work continues to further our understanding of an area of science that captures our imagination, and yet eludes our comprehension. His experiments are paving the way for new innovations that may change our world.
