Spin-Orbit Caloritronics

Utilizing spin-orbit coupling to enable the electrical manipulation of ferromagnets has recently attracted a considerable amount of interest. This spin-orbit torque [1] appears in magnetic systems displaying inversion symmetry breaking. Another adjacent emerging topic, spin caloritronics [2], aims at exploiting magnonic spin currents driven by temperature gradients, allowing for the transmission of information and the control of magnetic domain walls. In this work, we demonstrate that a magnon flow generates torques on the local magnetization when subjected to Dzyaloshinskii-Moriya interaction (DMI) just as an electron flow generates torques when submitted to Rashba interaction [3]. A direct consequence is the capability to control the magnetization direction of a homogeneous ferromagnet by applying a temperature gradient or local RF excitations. Merging the spin-orbit torques with spin caloritronics is rendered possible by the emergence of DMI in magnetic materials and opens promising avenues in the development of chargeless information technology. [1] Miron et. al, Nature Materials 9, 230 (2010); [2] Bauer, et al. Nat. Mater. 11, 391 (2012); [3] A. Manchon and S. Zhang, Phys. Rev. B 78, 212405 (2008).