Control of spin transport in antiferromagnetic insulators

Effective spin current switching is a key process for spin transistor. Unfortunately, it has proven to be challenging in metallic or semiconducting materials, in which the propagation of a spin current relies on electron diffusion. Recently, spin currents are found to be carried by magnons in antiferromagnetic insulators, promising alternative methods for manipulating spin. Here, the recent progress on efficient manipulating spin currents in antiferromagnetic insulators will be reviewed. The switching of the spin current becomes possible by controlling the structural phase and magnetism of the material. The underlying physics will be discussed with the introduction of the concept of spin colossal magnetoresistance. These findings pave the road towards antiferromagnetic-insulator-based spin transistors and memories. (author)