Adiabatic and nonadiabatic spin torques induced by spin-triplet supercurrent

Abstract

We study spin transfer torques induced by a spin-triplet supercurrent in a magnet with the superconducting proximity effect. By a perturbative approach, we show that spin-triplet correlations realize new types of torques, which are analogous to the adiabatic and non-adiabatic ($\beta$) torques, without extrinsic spin-flip scattering. Remarkable advantages compared to conventional spin-transfer torques are highlighted in domain wall manipulation. Oscillatory motions of a domain wall do not occur for a small Gilbert damping, and the threshold current density to drive its motion becomes zero in the absence of extrinsic pinning potentials due to the nonadiabatic torque controlled by the triplet correlations.