Shunsuke Kitou

A layered cake where each tier conducts electricity differently: that's the structure of the crystal La3Ni2O7, a compound of nickel, lanthanum, and oxygen. Current flows differently along the layers than across them.

A house with cork walls suddenly gets covered in copper sheets, but only when frost sets in. That's roughly how FeSb₂ behaves when made into a film just a few atomic layers thick. Under normal conditions, it's a narrow-gap insulator: electrons sit tightly in place like spectators in an overcrowded hall.