Contrary to conventional wisdom that spin dynamics induced by current are exclusive to metallic magnets, we theoretically predict that such phenomena can also be realized in magnetic insulators, specifically in the magnetoelectric antiferromagnet ${\mathrm{Cr}}_2{\mathrm{O}}_3$. We reveal that the displacement current driven by the terahertz electric field is able to generate a Néel spin-orbit torque in this insulating system. By introducing an alternative electric dipole order parameter, i.e., the antiferroelectric vector, arising from the dipole moment at ${\mathrm{Cr}}^{3+}$ sites, we combine symmetry analysis with a Lagrangian approach and uncover that the displacement current couples to the antiferromagnetic spins and enables ultrafast control of antiferromagnetic order. The derived equations of motion show that this effect competes with the linear magnetoelectric response, offering an alternative pathway for manipulating antiferromagnetic order in insulators. Our findings establish insulator antiferromagnets as a viable platform for electric-field-driven antiferromagnetic spintronics and provide general design principles for nonmetallic spin-orbit torque materials.

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• Magnetoelectric effect
• Spin dynamics
• Spin-orbit torque
• Ultrafast magnetic effects
• Antiferromagnets