The dance floor is packed with people, each moving on their own. Suddenly, some of them break into pairs (spinning around, barely noticing their neighbors) while the rest line up in chains. That's roughly how atoms behave in the metal CsCr₃Sb₅, a member of the kagome metals, whose crystal lattice resembles a woven basket.
Upon cooling, a charge density wave emerges in this material — electrons and atoms oscillate in sync, creating an ordered pattern. It was known that the pattern has a period of 4×1, but the exact arrangement of atoms remained a mystery. The authors of the study decoded the structure: chromium atoms form tight pairs (dimers) separated by single chains. Inside each pair, the spins, tiny magnetic arrows, point in opposite directions, and this antiferromagnetic interaction turns out to be the strongest in the system.
Under pressure, the dance floor seems to shrink, and the pairs begin to break apart. The charge wave and magnetic order vanish, and in their place superconductivity emerges — current flows without loss. The most intriguing part is that the superconducting state arises from a "bad" liquid where electrons behave differently than in ordinary metals. The scientists suspect that it is the fluctuations of the magnetic pairs, their breaking and re-forming, that help electrons pair up into Cooper pairs, which are essential for superconductivity.
This discovery adds a new brushstroke to our understanding of how different types of order coexist and compete in complex materials. Perhaps in the future, such systems could help create superconductors that work at higher temperatures: we just need to properly "choreograph" the atomic dances.
The name "kagome" comes from Japanese culture: it refers to a basket-weaving pattern resembling a lattice of interwoven triangles. That's exactly the shape of the atomic layer in these metals.
In Peter Watts's novel Blindsight, alien beings use quantum effects to process information — much like electrons in kagome metals can collectively organize into exotic states.