A team of scientists led by the U.S. Department of Energy’s (DOE) Argonne National Laboratory has identified a rare, switchable quantum property in a new type of nickel sulfide material. The discovery could have applications in high-speed transistors, adaptive sensors and other devices that require a material’s electronic structure to be controlled on the fly. The research is published in the journal Matter.

The compound, K_xNi₄S₂ (0 ≤ x ≤ 1), contains nickel and sulfur sandwiched between layers of potassium. The “(0 ≤ x ≤ 1)” in the name means that the amount of potassium in the material can vary from no potassium at all to a full potassium atom, depending on the sample.

First detailed in a 2021 paper, it was created as part of an ongoing quest to develop more superconductors. As researchers examined the layered material’s characteristics, they happened upon a remarkable feature: applying an electrical current could drive the potassium layers out, collapsing the sandwich and changing the material’s structure.