Keep it simple and switch to pure tellurium

Researchers, inspired by neurobiological functions and architecture of the human brain, have been developing neuromorphic computing by using artificial neurons and synapses to perform processing and storage in the same physical place. However, no conceptual technology can become reality without hardware. The class of memory devices known as phase change (PC) memories is expected to enable more efficient learning algorithms in neuromorphic computers, owing to their capability to also work as a processing unit (1). On page 1390 of this issue, Shen et al. (2) use pure elemental tellurium to build an electrical switch with a large drive current and rapid switching speed that can be used to efficiently operate PC cells in the cross-point memory architecture (see the figure). By creating the logic gate out of a single element, the design gets around challenges presented by material stoichiometry and selective elemental migration. The single-element design represents a step toward high-density, fast, and nonvolatile PC memories.