July 10, 2025
Neither solid nor liquid : Neutrons help reveal an exotic state of matter
A team of researchers recently used the thermal-neutron two-axis diffractometer D23 at the ILL to investigate Na2 BaCo(PO4 )2 (NBCP), a material that surprisingly behaves as a ‘spin supersolid’ -a state combining properties of both a solid and a liquid. Neutrons, acting like tiny magnets themselves, were the ideal probes to reveal the hidden magnetic order and dynamics within this material. This discovery, which is also relevant for energy-efficient cooling, provides the first real-life evidence of a supersolid state in a quantum magnet.