Dual quantum spin Hall insulator by density-tuned correlations in TaIrTe(4). (https://pubmed.ncbi.nlm.nih.gov/38509374/)

These scientists wanted to explore a special type of material that has the potential to show some really interesting behavior when it comes to how its electrons move around. They looked at a material called TaIrTe4, which is a very thin layer made up of just a few atoms.

First, they found that when there are no extra electrons added to this material, it behaves like something called a quantum spin Hall insulator. This means that it can conduct electricity in a special way along its edges. When they added some extra electrons to the material, they found that it went from being metallic (able to conduct electricity) to becoming an insulator (unable to conduct electricity) in a way that was unexpected based on its normal behavior.

What was really interesting is that within this insulating state, they observed the emergence of the quantum spin Hall state again. This was surprising because usually when a material becomes an insulator, it doesn't show this special behavior.

The scientists think that this unexpected behavior might be due to a special arrangement of the electrons within the material, which could lead to a new way of creating materials with unique properties that could be useful for different technologies in the future.

Tang J., Ding TS., Chen H., Gao A., Qian T., Huang Z., Sun Z., Han X., Strasser A., Li J., Geiwitz M., Shehabeldin M., Belosevich V., Wang Z., Wang Y., Watanabe K., Taniguchi T., Bell DC., Wang Z., Fu L., Zhang Y., Qian X., Burch KS., Shi Y., Ni N., Chang G., Xu SY., Ma Q. Dual quantum spin Hall insulator by density-tuned correlations in TaIrTe(4). Nature. 2024 Mar 20. doi: 10.1038/s41586-024-07211-8.