WA and Bristol researchers make quantum computing breakthrough

Researchers from the University of Western Australia (UWA) and the University of Bristol have made a breakthrough in advancing quantum computing by simulating ‘quantum walks’.

PhD student Thomas Loke, from UWA’s School of Physics, said the simulation enabled information in a computer to be manipulated and travel in many ways at the same time.

“The software I developed allowed the research team to test quantum walks and complete a complex algorithm on the computer, providing evidence that even an early prototype of the quantum computer can do more than a traditional computer,” Loke said.

In computing, ‘quantum walks’ are the quantum version of traditional ‘random walks’, but they do not converge to limiting distributions and may spread significantly faster or slower.

The work included contributions from UWA’s Quantum Computing Group led by professor Jingbo Wang; the experimental team and the University of Bristol, led by professor Jeremy O’Brien and Dr Jonathan Matthews, and quantum complexity theory research led by Ashley Montanaro at the University of Bristol.

Loke said this breakthrough was the first experimental implementation of his quantum codes, and he anticipates several more will follow.

“Building a large-scale quantum computer is one of the biggest global engineering challenges and this research has brought us one step closer in this significant advancement for global technology,” he said.

Quantum computers, which promise unprecedented computing power, rely on single photons, electrons and atoms, unlike traditional computers that use transistors implanted into a silicon chip.

Information on traditional computers is stored in two states (0s or 1s), but on a quantum computer both states are used simultaneously, enabling much larger capabilities.

The research, published in detail in the Nature Communications Journal, notes that quantum walks have shown much potential as a framework for developing new quantum algorithms. It also details how they experimentally implemented a quantum circuit on an example circulant graph using a two-qubit photonics quantum processor.