Key component to scale up quantum computing invented
Sydney team develops microcircuit based on Nobel Prize research
Invention of the mrowave circulator is part of a revolution in device engineering needed to build a large-scale quantum computer.
A team at the University of Sydney and Microsoft, in collaboration with Stanford University in the US, has miniaturised a component that is essential for the scale-up of quantum computing. The work constitutes the first practical application of a new phase of matter, first discovered in 2006, the so-called topological insulators.
Beyond the familiar phases of matter – solid, liquid, or gas – topological insulators are materials that operate as insulators in the bulk of their structures but have surfaces that act as conductors. Manipulation of these materials provide a pathway to construct the circuitry needed for the interaction between quantum and classical systems, vital for building a practical quantum computer.
Theoretical work underpinning the discovery of this new phase of matter was awarded the 2016 Nobel Prize in Physics.
The Sydney team’s component, coined a microwave circulator, acts like a traffic roundabout, ensuring that electrical signals only propagate in one direction, clockwise or anti-clockwise, as required. Similar devices are found in mobile phone base-stations and radar systems, and will be required in large quantities in the construction of quantum computers. A major limitation, until now, is that typical circulators are bulky objects the size of your hand.
This invention, reported by the Sydney team today in the journal Nature Communications, represents the miniaturisation of the common circulator device by a factor of 1000. This has been done by exploiting the properties of topological insulators to slow the speed of light in the material. This minaturisation paves the way for many circulators to be integrated on a chip and manufactured in the large quantities that will be needed to build quantum computers.
Source : University of Sydney