Scientists have identified a one-dimensional topological insulator that could revolutionize quantum computing and solar cell efficiency. The revolutionary discovery paves the way for advances in quantum computing and solar cell efficiency.

Researchers have discovered a new topological insulator (TI), a unique state of matter that differs from traditional metals, insulators, and semiconductors. Unlike most known TIs, which are 3D or 2D, this TI is 1D. This pioneering work is expected to advance the development of qubits and high-efficiency solar cells.

The research, conducted by scientists from Tohoku University, Osaka University, Kyoto Sangyo University, High Energy Accelerator Research Organization (KEK) and National Institute of Quantum Science and Technology, was published in the journal. Nature.

A breakthrough in the potential of quantum computing

TIs have an interior that acts as an electrical insulator, meaning electrons can’t move easily; their surface acts as an electrical conductor, while electrons can move across the surface. Since the advent of 3D TIs in the 2000s, researchers have been searching for new ones. However, one-dimensional TIs remain largely elusive.

“One-dimensional TIs are particularly interesting because the electric charges that appear at their extremes actually form qubits, the fundamental unit of information in quantum computing. Therefore, they are of vital importance for quantum physics,” says Kosuke Nakayama, an associate professor at the Graduate School of Science at Tohoku University and co-author of the study.

Research methodology

Nakayama and his colleagues focused their attention on tellurium (Te), a semiconductor used mostly commercially in solar panels and thermoelectric devices. Recent theoretical predictions suggested that single-stranded chains might actually be one-dimensional TIs. To test this, the team needed to observe the electric charges confined at the extremes of these circuits.

This required the preparation of clean Te chain edges without structural damage, which was made possible by using a newly developed gas cluster ion beam (GCIB) system that can modify surfaces with nanometer precision. They then visualized the spatial distribution of electric charges using microfocused beam angle-resolved photoemission spectroscopy (ARPES). Their research confirmed that electric charges do indeed appear at the ends of the chains, thus confirming the one-dimensional nature of TI Te.

Implications for future technologies

Nakayama emphasized that their research is an important step toward understanding the properties of one-dimensional TIs and will provide many benefits. “The charges at the extreme ends of one-dimensional TIs have various applications: qubits, high-efficiency solar cells, high-sensitivity photodetectors, and nanotransistors. Our discovery of one-dimensional TIs will help accelerate research into these applications.”