Microsoft’s Station Q quantum computing lab at the University of Sydney is set to embark on a new chapter in its research, moving to scale up its next generation of “quantum-engineered devices”.
The devices in question will form the heart of what the Microsoft-backed lab claims is the first practical topological quantum computers.
By now, the idea behind quantum computing is fairly well established. Unlike classical computing, which uses digital bits as binary switches to carry out calculations, quantum computing makes use of the unusual properties of subatomic quantum bits – or qubits – to perform calculations.
A topological quantum computer employs qubits using subatomic particles called Majorana fermions, a particle that is also its own antiparticle, will have their information encoded through their topology, or geometry.
The first generation of quantum bits suffers from interference from electromagnetic ‘noise’. This means they lack robustness and are proving very difficult to scale up to a fault-tolerant, universal quantum computer.
It has long been theorised that Majorana fermions could help scientists to build more robust quantum computers. Indeed, Station Q researchers suggest that by braiding the Majoranas, quantum information is encoded in a way that is highly resistant to interference.
As it turns out, a new study by Dr Maja Cassidy, who is based at the University of Sydney’s Station Q lab, has confirmed one of the prerequisites for building these devices.
Now, researchers at Sydney’s Station Q lab are set to build the “next generation” of devices that will use Majorana fermions as the basis for quantum computers.
In preparation, Station Q will move scientific equipment into the university’s Nanoscience Hub clean rooms over the next few months as it increases capacity to develop quantum machines.
Cassidy said that building such quantum devices is a “bit like going on a detective hunt”.
“When Majorana fermions were first shown to exist in 2012, there were many who said there could be other explanations for the findings,” she said.
The challenge to show that the latest findings were caused by Majoranas was put to a research team led by Professor Leo Kouwenhoven, who now leads Microsoft’s Station Q lab in the Netherlands.
The new research paper, published on 7 September, meets an essential part of that challenge.
In essence, the research aims to prove that electrons on a one-dimensional semiconducting nanowire will have a quantum spin opposite to its momentum in a finite magnetic field.
“This information is consistent with previous reports observing Majorana fermions in these nanowires,” Cassidy said.
Cassidy conducted the research while at the Technical University Delft in the Netherlands, where she held a post-doctorate position.
She has since returned to Australia and is based at the University of Sydney Station Q partnership with Microsoft.
For University of Sydney Professor and Station Q Sydney director, David Reilly, the Majorana fermion work being undertaken by Cassidy and Australian lab is “practical science at the cutting-edge”.
“We have hired Dr Cassidy because her ability to fabricate next-generation quantum devices is second to none,” Reilly said.
The new research comes just over a month after Microsoft revealed it had gone all in on its quantum computing research partnership with the University of Sydney, striking a multi-year global agreement with the institution.
The deal sees Microsoft commit to a new, long-term phase of its investment at the university, with the funding expected to result in state-of-the-art equipment, see the recruitment of new staff, help build out the nation’s scientific and engineering talent, and focus research project funding into the university.
In April, Microsoft revealed it would double the size of the lab, in a move expected to see at least 20 additional researchers come on board.
Quantum computing has largely been relegated to the realm of research by the likes of Station Q and other such university-affiliated labs.
However, in August, the University of NSW (UNSW) made a move to commercialise its quantum computing technology with the launch of what is being touted as Australia’s first quantum computing company.
The $83 million venture, from which the new company, Silicon Quantum Computing Pty Ltd, emerged, has received backing from UNSW itself, which has contributed $25 million, as well as the Commonwealth Bank of Australia and Telstra, which are contributing $14 million and $10 million, respectively.
The creation of the company is intended to help drive the development and commercialisation of a 10-qubit quantum integrated circuit prototype in silicon by 2022, as the forerunner to a silicon-based quantum computer.
The company will work alongside the Australian Research Council (ARC) Centre of Excellence for Quantum Computation and Communication Technology (CQC2T), operating from new laboratories within the Centre’s UNSW headquarters.