Kajal Tiwari

Abstract Dimensionality and magnetic anisotropy jointly determine whether long-range magnetic order survives in low-dimensional magnets. Although theory predicts that perpendicular magnetic anisotropy can stabilize ferromagnetism in two-dimensional systems, an experimental realization of a continuous crossover from a three-dimensional Heisenberg-type system to a two-dimensional Ising-type ferromagnet has remained challenging.

Editor’s summary Spin glasses are magnetic systems in which factors such as geometry and disorder prevent the formation of long-range magnetic order. Like window glass, they are characterized by slow dynamics and they exhibit aging. Pal et al. observed evidence for a spin glass in the van der Waals magnet Fe3GeTe2. Surprisingly, spin-glass signatures persisted as the thickness of the sample was reduced all the way to the single unit cell.