Spin Dynamics and Domain Wall Motion in Magnetic Systems

Magnetic materials exhibit a rich tapestry of dynamical phenomena arising from the collective behaviour of electron spins. Spin dynamics encompasses the time-dependent evolution of magnetic moments under the influence of internal interactions, external fields and currents. A central aspect of spin dynamics in extended magnets is the motion of domain walls, the narrow regions separating magnetic domains of differing orientation. Domain walls respond to magnetic fields, spin-polarised currents and thermal gradients, enabling controlled manipulation of magnetic information at nanometre scales. Fundamental interactions such as exchange coupling, magnetocrystalline anisotropy and Dzyaloshinskii–Moriya interaction dictate the structure and mobility of walls, while damping and inertial effects govern their dynamic response. The interplay between spin waves (or magnons) and domain walls has opened pathways towards novel magnonic devices where information can be carried by wave packets and gated via mobile textures. Recent advances highlight ultrafast domain wall displacement by optical pulses, emergent electromagnetic inductance associated with noncollinear spin textures, and spin-orbit torque mechanisms that couple charge currents to spin motion. These developments promise energy-efficient memory and logic elements, ultra-high-frequency oscillators and magnonic circuits, illustrating the global significance of harnessing spin dynamics for future information technologies.

Research from Nature Portfolio

Investigations of emergent electromagnetic induction in helimagnetic metals have revealed that disordered spin helices can produce a pronounced nonlinear response to alternating currents. Studies on Tb₅Sb₃ demonstrate that current-driven spin motions in a highly disordered helimagnet generate large emergent inductances, reaching tens of microhenries in micrometre-scale devices. This effect arises from distributions of spin-helix periodicities and noncollinear textures, pointing to new routes for designing on-chip inductive elements. In a complementary foundational work, antiferromagnetic domain walls have been shown to act as natural polarizers and retarders for spin waves. In the presence of Dzyaloshinskii–Moriya interaction, a single domain wall in an antiferromagnet can filter circular spin-wave polarizations or introduce phase shifts, offering simple yet flexible schemes for magnonic information processing by exploiting the full polarisation degree of freedom.

Spin Dynamics and Domain Wall Motion in Magnetic Systems publication trend

The graph below shows the total number of articles in spin dynamics and domain wall motion in magnetic systems across all publications each year (not limited to Nature Index journals).

Technical terms

Spin wave (magnon): Collective oscillation of magnetic moments propagating through a material.

Domain wall: Narrow interface between regions of uniform but differently oriented magnetisation.

Spin-orbit torque (SOT): Torque on a magnetic moment induced by spin currents generated via spin–orbit coupling.

Dzyaloshinskii–Moriya interaction (DMI): An antisymmetric exchange interaction stabilising chiral spin textures.

Walker breakdown: Threshold at which steady domain wall motion transitions to oscillatory or inertial regimes.

References

1. Enhanced emergent electromagnetic inductance in Tb5Sb3 due to highly disordered helimagnetism. Communications Physics (2024).
2. Spin–Orbit Torque in Single-Molecule Junctions from ab Initio. The Journal of Physical Chemistry Letters (2024).
3. Antiferromagnetic domain wall as spin wave polarizer and retarder. Nature Communications (2017).
4. Unveiling domain wall dynamics of ferrimagnets in thermal magnon currents: Competition of angular momentum transfer and entropic torque. Physical Review Research (2020).
5. Inertial displacement of a domain wall excited by ultra-short circularly polarized laser pulses. Nature Communications (2017).
6. Ultralow-loss domain wall motion driven by a magnetocrystalline anisotropy gradient in an antiferromagnetic nanowire. Physical Review Research (2020).
7. Electromagnetic response in spiral magnets and emergent inductance. Communications Physics (2021).