According to researchers at the University of Waterloo's Institute for Quantum Computer (IQC), a form of quantum weirdness is an important component for constructing quantum computers.
The researchers have demonstrated that a strange feature of quantum theory known as contextuality is an essential resource to realize the "magic" needed for universal quantum computation.
Scientists have long struggled to identify realistic ways to manage fragile quantum states. In pursuit of this goal, the researchers have confirmed theoretically that contextuality is an essential resource needed for realizing the benefits of quantum computation.
"Before these results, we didn't necessarily know what resources were needed for a physical device to achieve the advantage of quantum information. Now we know one," explained lead author Mark Howard, a postdoctoral fellow at IQC, in a statement. "As researchers work to build a universal quantum computer, understanding the minimum physical resources required is an important step to finding ways to harness the power of the quantum world."
The term magic describes a specific technique to constructing noise-resistant quantum computers called magic-state distillation. Magic states behave as an important, but hard to realize and manage, additional ingredient that enhances the power of a quantum device to accomplish the enhanced processing power of a universal quantum computer.
"These new results give us a deeper understanding of the nature of quantum computation. They also clarify the practical requirements for designing a realistic quantum computer," noted Joseph Emerson, professor of Applied Mathematics and Canadian Institute for Advanced Research fellow. "I expect the results will help both theorists and experimentalists find more efficient methods to overcome the limitations imposed by unavoidable sources of noise and other errors."
Contextuality refers to the fact that in quantum systems, a measurement will necessarily impact the thing being measured. For example, if you want to measure the spin of a particle, it's incorrect to think that there is a "real" spin just waiting to be identified. Instead, the very act of measuring the spin helps determine what it will be.
The findings are described in greater detail in the journal Nature.
Source : http://www.sciencerecorder.com/news/contextuality-puts-the-magic-in-quantum-computing-researchers-say/
