Illustration of superconductivity. Credit: Croucher.

New insights into quasiparticles could boost quantum computing

10 September 2024

Researchers led by Dr Junwei Liu from the Hong Kong University of Science and Technology, Professor Jinfeng Jia, and Dr Yaoyi Li from Shanghai Jiao Tong University have identified multiple Majorana zero modes (MZMs) in a single vortex of superconducting tin telluride (SnTe). This could lead to improvements in quantum computing.

MZMs are unique quasiparticles that could potentially serve as the building blocks for fault-tolerant quantum computers. Unlike ordinary particles, MZMs exhibit non-Abelian statistics. This non-Abelian behaviour is what makes MZMs so promising for fault-tolerant quantum computing. It provides a way to perform quantum operations that are inherently protected from certain types of errors, which is a significant challenge in current quantum computing approaches.

The research team's new approach leverages crystal symmetry to control the coupling between MZMs, eliminating previous challenges in their manipulation. They used advanced low-temperature scanning tunnelling microscopy and high-quality sample growth techniques to see big changes in the zero-bias peak—a strong sign of MZMs—in a SnTe/Pb heterostructure when the magnetic fields were tilted.

This discovery creates new avenues for detecting and manipulating crystal-symmetry-protected multiple MZMs, opening the way for experimental demonstrations of non-Abelian statistics and the construction of new types of topological qubits and quantum gates.

The findings, published in Nature, with Chun Yu Wan from the Hong Kong University of Science and Technology and Dr Hao Yang and Dr Tengteng Liu from Shanghai Jiao Tong University as the co-first authors, represent an important step towards realising fault-tolerant quantum computers and could eventually have far-reaching implications for the future of quantum technology.