Abstract: Altermagnets combine advantages of antiferromagnets with a momentum-dependent spin splitting that can arise without spin–orbit coupling. This unusual combination creates new opportunities for generating spin currents and controlling magnetic order. In this colloquium, I will discuss recent theoretical advances that connect the symmetry of altermagnets to the manipulation of magnetic textures using electrical currents, temperature gradients, and supercurrents.

I will first introduce how altermagnetic symmetry gives rise to unconventional spin-transfer torques acting on domain walls and skyrmions. These torques can induce domain-wall precession, slow wall propagation for certain current directions, and produce an anisotropic skyrmion Hall effect [1]. I will then show how related mechanisms emerge in insulating altermagnets, where thermally excited spin waves carry angular momentum. The interplay of magnon transport and entropic forces leads to distinctive responses to temperature gradients, including fast skyrmion motion with strongly suppressed transverse deflection along selected crystal directions [2]. These predictions provide signatures of altermagnetic symmetry in the dynamics of magnetic textures.

Extending these ideas to superconducting hybrids, I will describe how the interplay of altermagnetic spin splitting and interfacial spin–orbit coupling allows a supercurrent to exert a torque on the Néel order. This coupling enables domain-wall motion and reversal of the magnetic orientation within a wall, while the magnetic configuration can, in turn, tune the supercurrent. Such reciprocal control offers a route toward magnetic manipulation with reduced electrical dissipation [3]. I will also briefly discuss how optical driving can induce spin splitting in otherwise spin-degenerate antiferromagnets, enabling new approaches to spin generation without spin–orbit coupling [4].

References

[1] H. Vakili, E. Schwartz, and A. A. Kovalev, “Spin-Transfer Torque in Altermagnets with Magnetic Textures,” Physical Review Letters 134, 176401 (2025). arXiv:2412.11274.

[2] E. Schwartz, H. Vakili, and A. A. Kovalev, “Thermomagnonic Torques in Insulating Altermagnets,” arXiv:2512.14660 (2025).

[3] H. Vakili, M. Ali, I. Žutić, and A. A. Kovalev, “Supercurrent-Driven Néel Torque in Superconductor/Altermagnet Hybrids,” arXiv:2603.22243 (2026).

[4] B. Li, D.-F. Shao, and A. A. Kovalev, “Floquet Spin Splitting and Spin Generation in Antiferromagnets,” Physical Review Letters 136, 166701 (2026). arXiv:2507.22884.