Emergent Topology Arises in Quantum-Critical CeRu4Sn6

Researchers at TU Wien report that the quantum material CeRu4Sn6 enters a quantum-critical regime at ultra-low temperatures where electrons lose their particle-like character, yet the system hosts an emergent topological semimetal state. They observed a spontaneous (anomalous) Hall effect without an external magnetic field, linking quantum fluctuations to topology and suggesting that topological properties can arise even when the conventional particle-picture fails. The work also points to a generalized, emergent view of topology and proposes focusing on quantum-critical materials to discover new topological phases.