Ultrafast manipulation of material properties with light could stimulate the development of novel electronics, including quantum computers.

Weyl metals such as tantalum arsenide (TaAs) are predicted to have novel properties arising from a chirality of their electron spins. Scientists induced an imbalance between the left- and right-handed spin states, resulting in a topologically protected current. This was the first time this phenomenon, known as the chiral anomaly, has been observed.

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.