Symposium X—MRS/The Kavli Foundation Frontiers of Materials

Michelle Simmons, University of New South Wales

Engineering Qubits in Silicon with Atomic Precision

Written by Andrew M. Fitzgerald

Renowned quantum physicist and 2018 Australian of the Year Michelle Simmons gave an exciting lecture focused on recent advancements in silicon-based quantum computing. As the CEO and founder of Silicon Quantum Computing and the director of the Australian Research Council’s Centre of Excellence for Quantum Computation & Communication Technology, Simmons highlighted many achievements and contributions that she and her team have made in engineering atomic-scale qubits as they set records in coherence times and fidelity.

Simmons outlined her team’s progress in addressing the main challenges of scalability, precision, and efficiency in quantum computing. By using silicon as a manufacturable platform, they have achieved a high level of control over qubit design. This includes sub-nanometer precision in placing phosphorus atoms, ensuring identical quantum dot sizes, and enabling rapid (as well as efficient) scaling of qubit counts. These advancements allow for highly coherent, stable, and fast qubits, which are critical for building a large-scale, error-corrected quantum computer.

In her lecture, Simmons also showcased a few quantum devices that she and her team have been developing. One device, a quantum machine learning accelerator, involved a quantum feature generator that outperforms classical methods, demonstrating quantum computing’s potential to make a large impact in the computational world. Another device, an analog simulator, carries out simulations of topological states and condensed matter phenomena, such as metal-insulator transitions, suggesting that quantum computing will impact fields beyond quantum computing, including condensed matter physics. Overall, these devices emphasize the ability of atomic-scale engineering to push the field of quantum research forward.

Simmons further detailed her team’s achievements in quantum computing. Qubit gates operating at ~99% fidelity and a Grover’s algorithm with a world record efficiency of 98.87% demonstrate the positive impact of her materials-first approach. These results position silicon-based qubits as a leading platform for scalable quantum systems. Moreover, Simmons emphasized that her team can design, fabricate, and test quantum devices within a week, an exciting accomplishment that accelerates the device development timeline. This capability allows for rapid iteration and positions her group as a leader in the quantum computing research field.

Looking ahead, Simmons expressed optimism about the timeline for achieving large-scale quantum computers. With the right materials and techniques, her team projects that a fully error-corrected quantum computer could be realized by 2033. This prediction reflects the great amount of progress made by researchers under her leadership.

In addition to groundbreaking advancements in quantum technology, Simmons’ work offers significant contributions to condensed matter physics by studying the interactions between qubits and their environment. This dual focus not only accelerates the development of quantum computing but also enhances our understanding of materials behaviors at the atomic scale. Globally recognized as a pioneer in quantum technology, Simmons has pushed the boundaries of what is possible in the field.

Symposium X—MRS/The Kavli Foundation Frontiers of Materials features lectures aimed at a broad audience to provide meeting attendees with an overview of leading-edge topics.