Spin-polarized current-induced instability in the spin-valve antiferromagnetic layer

We describe the dynamics of a compensated antiferromagnet (AFM) in the presence of spin-polarized current. The developed phenomenological model is based on the assumption that macrospins corresponding to different sublattices of AFM interact with the spin-polarized current independently. It is shown that spin-polarized current can i) be a source of the "negative friction"; ii) modify spin-wave spectra; and iii) switch the steady state of AFM. The value of the threshold current at which the switching between different steady states of AFM takes place depends upon the anisotropy of magnetic interactions