Scientists create "kagome metal"

Physicists from MIT, Harvard University, and Lawrence Berkeley National Laboratory have produced what the call "a kagome metal" — an electrically conducting crystal, made from layers of iron and tin atoms, with each atomic layer arranged in the repeating pattern of a kagome lattice.

In a paper published in Nature, the scientists explain that their creation was inspired by Japanese kagome baskets, which are typically made from strips of bamboo woven into a highly symmetrical pattern of interlaced, corner-sharing triangles.

"If a metal or other conductive material could be made to resemble such a kagome pattern at the atomic scale, with individual atoms arranged in similar triangular patterns, it should in theory exhibit exotic electronic properties," the researchers explain in a press release issued by the MIT.

In their experiment, the scientists flowed a current across the kagome layers within the crystal. After they did this, they observed that the triangular arrangement of atoms induced strange, quantum-like behaviors in the passing current. Instead of flowing straight through the lattice, electrons veered or bent back within the lattice.

"This behavior is a three-dimensional cousin of the so-called Quantum Hall effect, in which electrons flowing through a two-dimensional material will exhibit a 'chiral, topological state,' in which they bend into tight, circular paths and flow along edges without losing energy," the statement reads.

According to Joseph Checkelsky, assistant professor of physics at MIT, by constructing the kagome network of iron, which is inherently magnetic, the exotic behavior persists to room temperature and higher. This means that the charges in the crystal feel not only the magnetic fields from these atoms but also a purely quantum-mechanical magnetic force from the lattice. "This could lead to perfect conduction, akin to superconductivity, in future generations of materials," Checkelsky said.