Enhancement of spin-motive force in systems with broken inversion symmetry*

The exchange interaction between the conduction electron spin and the local magnetization is responsible for spin-transfer torque, which provides an promising way of manipulating the magnetization by charge current. The same interaction can also mediate an electric-voltage generation by dynamical magnetic textures, i.e., spin-motive force (SMF). A SMF reflects spatiotemporal variation of the magnetization, and thus offers a powerful method to probe and explore various dynamical magnetic textures.
The experimentally observed SMFs thus far are typically 100nV-1μV. To achieve larger SMF is deemed indispensable towards realization of spintronic devices actively exploiting SMF. In this work we address this problem demonstrating that, in the presence of Dzyaloshinskii-Moriya Interaction (DMI), the SMF due to field-induced domain-wall motion can be dramatically enhanced[1]. The presence of DMI leads to extra spatial rotation of the magnetization, which turns out to play a crucial role in the enhancement of SMF. Our results suggest a new perspective on inversion-symmetry-broken systems as a suitable stage for pursuit of larger SMF.

[1] Y. Yamane, arXiv:1808.10076.