The layered material (SnS)1.15(TaS2) resembles a stack of paper, where the sheets conduct electricity and the interlayers prevent them from sticking together. At ambient pressure, this material conducts current without resistance, making it a superconductor. But when you start compressing the stack, superconductivity weakens and completely disappears at around 14.7 GPa, like pressing a paper stack so hard that the sheets start rubbing against each other, hindering electron motion.

However, when the pressure was raised even further (to 80 GPa and beyond, up to 150 GPa) superconductivity unexpectedly returned. X-ray images showed that the atomic arrangement in the material did not change: the sheets stayed in place. So it's not about a rearrangement of the crystal lattice, but about the electrons themselves. At around 60 GPa, the sign of the Hall effect changed, as if the charge carriers in the conductor suddenly switched character: instead of negative particles, they began to behave like positive ones. This electronic reconstruction, it seems, brings superconductivity back.

This result shows that pressure is a convenient tool for controlling superconductivity in layered materials. Such materials, as natural heterostructures, are already interesting for electronics, and now there's a way to switch their properties without changing composition, just by squeezing or releasing.