Electrons take on diverse jobs in a compound

It was reported that two species of electrons in the same compound were found carrying superconductivity and anti-ferromagnetism, respectively. These two have different mass, one very light while the other quite heavy. This compound has quasi-3D stacked structure, nearly isomorphic to pnictide superconductors. I feel this is funny and many other rich phenomena might happen. "We found that the ZrCuSiAs-type crystal CeNi0:8Bi2 with a layered structure composed of alternate stacking of ½CeNixBið1Þ þ and Bið2Þ exhibits a superconductive transition at 4 K. The conductivities, magnetic susceptibilities, and heat capacities measurements indicate the presence of two types of carriers with notable different masses, i.e., a light electron responsible for superconductivity and a heavy electron interacting with the Ce 4f electron. This observation suggests that 6p electrons of Bi(2) forming the square net and electrons in CeNixBið1Þ layers primarily correspond to the light and heavy electrons, respectively."[PRL, 106:057002(2011)]