The iron-based superconductor material, Ba1−xKxFe2As2. Vadim Grinenko, Federico Caglieris/KTH Royal Institute of Technology
Twenty years ago, scientists first predicted electron quadruplets. Now, KTH Professor Egor Babaev, with the aid of international collaborators, has revealed evidence of fermion quadrupling in a series of experimental measurements on the iron-based material, Ba 1−x Kx Fe 2 As 2.
This is the first-ever experimental evidence of this quadrupling effect and the mechanism by which this state of matter occurs.