Spin Transport Dynamics in Magnetic Systems

Spin transport dynamics explores how the angular momentum associated with electron spin propagates through magnetic media and across interfaces. Unlike charge currents, spin currents can flow without net charge motion, enabling fundamentally new device paradigms in spintronics. In magnetic conductors and insulators, spins propagate either as conduction‐electron spin currents or as collective excitations known as magnons. The interplay of spin–orbit coupling, exchange interactions and interface scattering governs both amplitude and coherence of spin signals. Key phenomena include the spin Hall effect, which converts charge currents into transverse spin currents, and its inverse counterpart. In magnetic insulators, magnonic transport channels allow for low-dissipation spin propagation over micrometre distances. At interfaces between non-magnetic metals and magnetic layers, spin pumping and spin memory loss dictate transfer efficiency. Advances in nanoscale fabrication and measurement have revealed spatial oscillations of spin currents, memristive behaviour in single magnetic layers and temperature-dependent interface torques. These insights underpin applications in non-volatile memory, neuromorphic computing and quantum devices, highlighting the global importance of mastering spin transport for future energy-efficient technologies.

Research from Nature Portfolio

Recent studies have demonstrated the conversion and control of pure spin currents in multilayer structures. One report showed that thermally excited magnons in an insulating garnet can mediate current drag across metal–insulator–metal stacks, enabling a tunable pure spin valve action without charge leakage. Another work employed collinear ferromagnet–insulator–ferromagnet stacks to detect magnonic spin currents by resonance spin pumping, revealing a spin-valve-like response that depends on relative magnetisation alignment. More recently, the emergence of anisotropic magneto-memristance in a single ferromagnetic layer was observed, where GHz-frequency resistance changes arise from current-induced torques combined with magnetoresistive effects, pointing to novel memory and neuromorphic device concepts.

Spin Transport Dynamics in Magnetic Systems publication trend

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

Technical terms

Spin current: A flow of spin angular momentum, with or without net charge transport.

Magnon: A quantised collective excitation of spins in a magnet, carrying angular momentum.

Spin Hall effect: The generation of a transverse spin current from a longitudinal charge current via spin–orbit coupling.

Inverse spin Hall effect: The conversion of a spin current into a transverse charge voltage.

Anisotropic magneto-memristance: A resistance change dependent on current-induced spin torques and magnetisation topology.

Spin memory loss: The reduction of spin current due to spin-flip scattering at an interface.

References

1. Direct Observation of Spin Current Oscillation in a Ferromagnet. Physical Review X (2024).
2. Giant Room Temperature Interface Spin Hall and Inverse Spin Hall Effects. Physical Review Letters (2016).
3. Observation of magnon-mediated current drag in Pt/yttrium iron garnet/Pt(Ta) trilayers. Nature Communications (2016).
4. Magnon detection using a ferroic collinear multilayer spin valve. Nature Communications (2018).
5. Calculating the spin memory loss at Cu|metal interfaces from first principles. Physical Review B (2022).
6. Anisotropic MagnetoMemristance. Communications Physics (2022).