Discovery of robust in-plane ferroelectricity in atomic-thick SnTe

Thinning a ferroelectric makes it better As a ferroelectric material becomes thinner, the temperature below which it develops its permanent electrical polarization usually decreases. Chang et al. fabricated high-quality thin films of SnTe that, in contrast to this conventional wisdom, had a considerably higher transition temperature than that of the material in bulk (see the Perspective by Kooi and Noheda). This was true even for single-unit cell films, whereas only slightly thicker films became ferroelectric above room temperature. This finding may enable the miniaturization of ferroelectric devices. Science , this issue p. 274 ; see also p. 221