Intrinsic spin and Neel pumping in AFMs

We developed a theory on how magnetic precession pumps uniform and staggered spin polarization and its symmetry arguments.

Accumulating spin polarization is one great challenges on spintronics which controls how spin is manipulated. Conventional schemes involve spin transfer torque and spin orbit torque, which have been demonstrated to be effective under electric or spin current. While these approaches are advanced technologically, they usually require heterostructure setup. In our recent work, we develop a perturbative theory based upon time-dependent Hamiltonian and reveal that magnetic precession in a magnetic material can intrinsically trigger spin accumulations. Furthermore, we seperate such an accumulation into uniform and staggered (Neel vector related). They both contain Fermi-sea and Fermi-surface contributions, and the mixed geometric feature (Berry curvature in exchange field space) are also elucidated. These lead to a magnetic group analysis for their fieldlike and dampinglike component emergences. We finally illustrate such a theory in low energy model and first-principles numerical simulations on A-type antiferromagnets. See our work that just appeared in Physical Review B, at https://journals.aps.org/prb/abstract/10.1103/ftsx-tzcb.