Decades ago a mechanism was proposed that described a quantum phase transition to an insulating ground state from a semi-metal (excitonic insulator, or EI) using very similar mechanics to those found in the BCS description of superconductivity. The discovery of this transition to an EI in InAs/GaSb quantum wells is striking not only for the long-sought experimental realization of important physics, but also the presence of recently proposed topological behavior.

Researchers discover that Sr1-yMn1-zSb2 (y,z < 0.1) is a so-called Weyl material that holds great promise for building devices that require far less power.