Emergent Inductance in Antiferromagnetic Systems with Spin-orbit Coupling

Abstract

Emergent inductance, with its magnitude L inversely proportional to the device cross-sectional area SC, offers substantial advantages for device scaling. In this article, we investigate emergent inductance in antiferromagnetic (AFM) systems with spin-orbit coupling (SOC). The opposite sublattice SOC configuration is found to be crucial for the observation of emergent inductance because the staggered SOC effective field can drive highly efficient AFM precession and promote the generation of sizable spin motive force (SMF). We derive the analytic formulas of the antiferromagnetic emergent inductance in a two-port nanodevice, which is robust up to sub-THz frequency range due to the ultrafast spin dynamics in AFMs. We find that careful design of material parameters, such as magnetic anisotropy and Gilbert damping, may satisfy large inductance and quality factor simultaneously in low frequency region with the trade-off of operating bandwidth sacrifice. The accuracy of our inductance formulas are verified by numerical simulations. A transition from linear to nonlinear inductance model is also found and quantitatively evaluated under large current density and high frequency region. Our work provides renewed insights into the Néel spin-orbit torque (SOT)-driven AFM ultrafast electrical response, and offers promises for the development of spintronic inductor device for high-density and sub-THz applications.