Turning quantum computing into a reality

Through demonstrating a better than 99.9% fidelity of quantum logic operations on individual qubits – UNSW Professor Andrea Morello and his team have discovered the necessary elements needed to start building a scalable quantum computer.

Working at the foundational stage, Prof. Morello’s research covers the development of hardware that can be used to build quantum computers. One of the many challenges to his work however is that despite decades of research, quantum computing, is still an unknown entity. “It’s not an improvement of something we already have, I’m making something that has never existed before, and no one other than those in the field have even a mental concept of what it looks like.”

While quantum computers are machines that currently exist in prototype form, they don’t necessarily have applications, use or benefit. Prof. Morello however knows that if created correctly, the potential for quantum computing is enormous.

"It’s predicted to have the capacity to solve problems that can’t otherwise be solved."

“Some of these issues have to do with data security, some with chemistry, medicine, material science, materials development and even finance,” says Prof. Morello.

Small steps, big outcomes

In 2012, Prof. Morello and his team created the world’s first working quantum bit based on a single atom in silicon. This significant discovery brought the world one step closer to seeing the creation of a quantum computer turn into a reality. “It was a big breakthrough,” he says. “It’s the thing that essentially made my career.”

This discovery was made through the consideration of physical objects with quantum states. “There are systems that are natively quantum but then we thought – what if you wanted to build a big, powerful and commercially valuable quantum computer that could adopt the technology that’s in the silicon computer chips we already use?” he asks. “What we did with this technology showed the world that in principle and practice this can be done – at the level of one quantum bit.”

Following this breakthrough, Prof. Morello and his team spent two years working on improving the performance of their discovery. Then in 2014, another breakthrough. “We showed we could hold the quantum information in the quantum bit for 30 seconds, which is an incredibly long amount of time,” he adds.

In 2016, this research was put to work by UNSW together with the Federal and State Governments, Commonwealth Bank and Telstra, who created a spin-off company to commercialise the technology. This organisation has since been split into Silicon Quantum Computing and Diraq. “All of this originated from the 2012 result,” says Prof. Morello.

CEO and founder of Diraq, Professor Andrew Dzurak notes that while the qubit devices Diraq uses are similar but not identical to those used by Prof. Morello’s team, his work has greatly informed their approach.

“Prof. Morello’s breakthrough results between 2010-2014 were instrumental in giving us confidence that the underlying physics of our technology approach made sense."

- Professor Andrew Dzurak

“Furthermore, he has also led the establishment of a professional four-year Bachelor of Engineering in Quantum Engineering at UNSW – the first of its kind in the world – which serves as a valuable generator of talent for our company,” says Professor Dzurak.

From left to right: Prof. Andrew Dzurak, A/Prof. Jarryd Pla and Prof. Andrea Morello. The three key authors of the paper written on the 2012 breakthrough.

Front cover of the Nature Journal of Science (20/1/2022 issue), where Prof. Morello and his colleague’s paper on 99% fidelity was published. The cover image shows an artist’s impression of spin qubits, the building blocks of a silicon quantum computer. The two red spheres are atomic nuclei surrounded by the wavefunction of an associated electron (the ellipse) and the four ‘lobes’ represent entanglement between the qubits.

A melting pot of minds

As Prof. Morello’s research continues, so do the positive outcome of his team’s work. “We had another big result in 2022 where we showed for the first time that we can do quantum logic operations between two quantum bits in silicon with better than 99% fidelity, so less than 1% errors, which is a very important breakthrough for applications.”

Prof. Morello believes it will still be another 10-20 years before the world has its first truly useful quantum computer. Therefore, his focus remains on the basic science and necessary work to develop the operation methods for a high-performance quantum processor. This is something he admits he cannot do alone. “I work at the very hardware side of things, like building basic pieces, but then there are those who think about the big picture,” he explains. “From physics to engineering, mathematics, computer science and beyond. We all need each other.”

While there’s no reason why a quantum computer should not eventually be manufacturable, Prof. Morello believes this in itself isn’t the end of the quantum story.

“Most people think the ultimate outcome from a century of quantum computing research is that we have a quantum computer that works, and it would be a machine that never existed before which can solve problems that could otherwise not be solved. Then there are others who think we may discover a new law of nature that prevents the quantum computer from existing. Either way – the outcome of continued research on quantum computing will be a revolution.”

- Professor Andrea Morrello