Atoms trapped by laser light have become excellent platforms for simulating solid state systems. These systems are also a playground for exploring quantum matter and even uncovering new phenomena not yet seen in nature.

Researchers at the Joint Quantum Institute* have shown that an optical lattice system exhibits a never-before-seen quantum state called a topological semimetal. The semimetal, which debuts in this week’s Advance Online Publication for the journal Nature Physics (DOI:10.1038/NPHYS2134}, can undergo a new type of phase transition to a topological insulator.

Topological insulators are one of the hottest topics in condensed matter research because of their dual-personality. They are insulators throughout the bulk of the material but are conductors along the edges.