A team of researchers at Monash University has uncovered a powerful new way to engineer exotic quantum states, revealing a robust and tunable three-dimensional flat electronic band in an ultrathin kagome metal, an achievement long thought to be nearly impossible. The study, “3D Flat Band in Ultra-Thin Kagome Metal Mn₃Sn Film,” by M. Zhao, J. Blyth, T. Yu and collaborators appears in Advanced Materials.

The discovery centers on Mn₃Sn films just three nanometers thick. Despite their extreme thinness, these films host a 3D flat band that spans the entire momentum space, offering an unprecedented platform for exploring strongly correlated quantum phases and designing future low-energy electronic technologies.

“Until now, 3D flat bands had only been observed in a few bulk materials with special lattice geometries,” said Ph.D. candidate and co-lead author James Blyth, from the Monash University School of Physics and Astronomy.