Spin torques and magnetic texture dynamics driven by the supercurrent in superconductor/ferromagnet structures

We introduce the general formalism to describe spin torques induced by the supercurrents injected from the adjacent superconducting electrodes into the spin-textured ferromagnets. By considering the adiabatic limit for the equal-spin superconducting correlations in the ferromagnet we show that the supercurrent can generate both the field-like spin transfer torque and the spin-orbital torque. These dissipationless spin torques are expressed through the current-induced corrections to the effective field derived from the system energy. The general formalism is applied to show that the supercurrent can either shift or move the magnetic domain walls depending on their structure and the type of spin-orbital interaction in the system. These results can be used for the prediction and interpretation of the experiments studying magnetic texture dynamics in superconductor/ferromagnet/superconductor Josephson junctions and other hybrid structures.Comment: published version, some typos are correcte

Proximity effect in superconductor/antiferromagnet hybrids: Neel triplets and impurity suppression of superconductivity

Two possible physical mechanisms of superconductivity suppression at superconductor/antiferromagnet (S/AF) interfaces, which work even for interfaces with compensated antiferromagnets, were reported. One of them suggests that the Neel order of the AF induces rapidly oscillating spin-triplet correlations in the S layer. They are called Neel triplets, and they suppress singlet superconductivity. Nonmagnetic disorder destroys this type of triplet correlations. As a result, the critical temperature of the S/AF bilayer grows with impurity strength. The second mechanism, on the contrary, suggests that nonmagnetic impurity scattering suppresses superconductivity in S/AF hybrids. The predictions were made in the framework of two different quasiclassical approaches [G. A. Bobkov et al. Phys. Rev. B 106, 144512 (2022) and E. H. Fyhn et al. arXiv:2210.09325]. Here we suggest the unified theory of the proximity effect in thin-film S/AF structures, which incorporates both pictures as limiting cases, and we study the proximity effect at S/AF interfaces for arbitrary impurity strength, chemical potential, and the value of the Neel exchange field.Comment: 7 pages, 9 figure