Kondo insulator - Wikipedia
2019-6-11 · In solid-state physics, Kondo insulators (also referred as Kondo semiconductors and heavy fermion semiconductors) are understood as materials with strongly correlated electrons, that open up a narrow band gap (in the order of 10 meV) at low temperatures with the chemical potential lying in the gap, whereas in heavy fermions the chemical potential is located in the conduction band.