Chiral Magnetism and Soliton Dynamics

Chiral magnetism describes magnetic systems in which broken inversion symmetry gives rise to spin configurations with a fixed sense of rotation or handedness. Such materials host non-collinear spin textures, including helical spirals and particle-like solitons, stabilised by the Dzyaloshinskii–Moriya interaction (DMI) in conjunction with exchange and anisotropy energies. Under applied fields or currents, these chiral structures can reconfigure into periodic soliton lattices or propagate as individual solitons, offering avenues for information storage and transport in spintronic devices. Advances in materials synthesis and characterisation have enabled the fine tuning of DMI strength, the real-space imaging of soliton dynamics and the elucidation of phase diagrams that map transitions between uniform ferromagnetic, helical and solitonic regimes. The capacity to control soliton creation, motion and annihilation underpins prospects for ultra-low-power magnetic memory and logical elements that exploit topological protection and length-scale discretisation inherent to chiral spin textures.

Research from Nature Portfolio

Detailed phase-diagram studies of a monoaxial chiral helimagnet have defined the boundaries between helimagnetic order, forced ferromagnetic alignment and the intermediate chiral soliton lattice, revealing critical exponents consistent with three-dimensional Heisenberg behaviour. Temperature- and field-dependent magneto-entropy analysis has confirmed the first-order nature of the onset of chiral soliton order above the Curie temperature, establishing a thermodynamic signature for soliton formation. Complementary work has demonstrated that externally applied spin-polarised currents can reliably nucleate and drive single chiral solitons in monoaxial helimagnets, with a threshold current density beyond which soliton stability is lost. In parallel, gate-tunable intercalation in a transition metal dichalcogenide has been used to engineer sizeable bulk DMI, enabling in situ control of topological Hall resistivity and Bloch-type chiral spin textures by voltage, thus providing a solid-state platform for electric-field manipulation of soliton lattices and related transport phenomena.

Chiral Magnetism and Soliton Dynamics publication trend

The graph below shows the total number of articles in chiral magnetism and soliton dynamics across all publications each year (not limited to Nature Index journals).

Technical terms

Chiral magnetism: Magnetism in which spin arrangements exhibit a fixed sense of rotation due to broken spatial inversion symmetry.

Dzyaloshinskii–Moriya interaction: An antisymmetric exchange interaction favouring orthogonal spin alignment and driving the formation of chiral spin textures.

Helimagnet: A magnetic state characterised by a continuous rotation of spins forming a helical modulation along a crystallographic axis.

Chiral soliton lattice: A periodic array of discrete magnetic solitons in which spins twist by quantised angles, stabilised under external fields.

Magnetic soliton: A localised, particle-like spin configuration that retains its shape during propagation and interactions.

Spin-transfer torque: A torque on the local magnetisation arising from the angular momentum carried by a spin-polarised current.

References

1. Critical Behavior and Macroscopic Phase Diagram of the Monoaxial Chiral Helimagnet Cr1/3NbS2. Scientific Reports (2017).
2. Dynamics of chiral solitons driven by polarized currents in monoaxial helimagnets. Scientific Reports (2020).
3. Tailoring Dzyaloshinskii–Moriya interaction in a transition metal dichalcogenide by dual-intercalation. Nature Communications (2021).
4. Consequences and Control of Multiscale Order/Disorder in Chiral Magnetic Textures. ACS Nano (2023).
5. Comparative Electronic Structures of the Chiral Helimagnets Cr1/3NbS2 and Cr1/3TaS2. Chemistry of Materials (2023).
6. Magnetic soliton confinement and discretization effects arising from macroscopic coherence in a chiral spin soliton lattice. Physical Review B (2015).