Electrical manipulation of a ferromagnet by an antiferromagnet

Abstract

We demonstrate that an antiferromagnet can be employed for a highly efficient electrical manipulation of a ferromagnet. In our study we use an electrical detection technique of the ferromagnetic resonance driven by an in-plane ac-current in a NiFe/IrMn bilayer. At room temperature, we observe antidamping-like spin torque acting on the NiFe ferromagnet, generated by the in-plane current driven through the IrMn antiferromagnet. A large enhancement of the torque, characterized by an effective spin-Hall angle exceeding most heavy transition metals, correlates with the presence of the exchange-bias field at the NiFe/IrMn interface. It highlights that, in addition to strong spin-orbit coupling, the antiferromagnetic order in IrMn governs the observed phenomenon.

Main text: 7 pages, 6 figures. Includes supplementary information of 10 pages, 8 figures. Changes from the previous version include a new control experiment, two new figures in the main text, expanded discussion on the origins of the observed effect. Additionally, 2 new supplementary sections have been added