Exotic magnetic vortices observed in atom-thin crystal for first time

Physicists at The University of Texas at Austin have experimentally confirmed a long-standing theoretical prediction about magnetism in ultra-thin materials by studying atomically thin sheets of nickel phosphorus trisulfide (NiPS3). Upon cooling the material to temperatures between –150 and –130 °C, they observed a rare magnetic phase called the Berezinskii–Kosterlitz–Thouless (BKT) phase, where atomic magnetic moments form tightly bound pairs of swirling vortices rotating in opposite directions within a single atomic layer. Further cooling led to a second transition into the six-state clock ordered phase, where magnetic moments lock into one of six symmetry-related directions. This sequence of magnetic transitions had been predicted since the 1970s but never fully demonstrated in a single system until now. This breakthrough validates the two-dimensional six-state clock model, a foundational theoretical framework in condensed matter physics, and reveals conditions under which nanoscale magnetic vortices naturally emerge in purely two-dimensional magnets. The observed vortices