A natural yellow, brownish-yellow, or grayish-black mineral that contains an oxide of calcium and titanium and sometimes embodies rare earth elements as well: Researchers have found a strange magnetism that takes place when two materials, identified as perovskites, are sandwiched or squeezed tightly together.

These particular perovskites are known as LAO (lanthanum aluminum oxide) and STO (strontium titanium oxide), and both of them are insulators; however, when they are sandwiched together, the resulting "heterostructure" (the interface that occurs between two layers or regions of dissimilar crystalline semiconductors) can conduct electricity at the surfaces where the materials meet.

When the two perovskites are cooled to near-absolute zero, the heterostructure becomes a superconductor, conducting electricity without any resistance.

Named for Russian mineralogist L. A. Perovski (1792-1856) in 1839.