Thermal Spin Transport Phenomena in Magnetic Systems

Thermal spin transport phenomena arise from the interplay between thermal gradients and magnetic order, giving rise to pure spin currents that carry angular momentum without net charge flow. This coupling between heat and spin—at the heart of spin caloritronics—enables control of magnetisation dynamics through temperature differences, and offers routes to energy harvesting, thermal management and low-power spintronic devices. Key manifestations include the spin Seebeck effect, which converts a longitudinal temperature gradient into a transverse spin current, and the spin Nernst effect, which generates a transverse spin accumulation from an in-plane heat flux. In insulating magnets, propagating spin waves or magnons transport heat and spin, while in metals and semimetals conduction electrons mediate thermally driven spin currents via spin–orbit coupling. Interface engineering and material design have become central to enhancing thermal spin conversion efficiencies, from hybrid ferromagnet/insulator structures to non-collinear antiferromagnets. Practical applications span waste-heat recovery, on-chip cooling, programmable thermal diodes and magnonic logic elements. Advances in optical and electrical detection techniques allow nanoscale mapping of heat-induced spin signals, shedding light on microscopic transport mechanisms and guiding the optimisation of spin caloritronic architectures.

Research from Nature Portfolio

Recent studies have demonstrated optical control of heat currents in magnetic films via a combination of the anomalous Ettingshausen effect and helicity-dependent magnetisation switching. By patterning visible-light illumination on garnet and metallic magnets, researchers have shown reversible steering of heat flow at the micron scale and on-off modulation of temperature profiles simply by tuning light polarisation. This ‘magneto-optical painting’ approach offers a non-invasive route to spatially programmable thermal landscapes in spintronic materials.

Investigations of heavy-metal/ferromagnet bilayers have revealed that a temperature gradient in the non-magnetic layer induces a transverse magnetoresistance traceable to the spin Nernst effect. Variations in heavy-metal composition and thickness influence the magnitude and sign of the transverse magnetoresistance, indicating that thermally generated pure spin currents in the heavy metal can rival electrically driven spin Hall currents. This work underscores the role of interfacial spin–orbit coupling in thermal spin transport.

Thermal Spin Transport Phenomena in Magnetic Systems publication trend

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

Technical terms

Spin Seebeck effect: Generation of a spin current in a magnetic material by applying a temperature gradient.

Spin Nernst effect: Transverse spin accumulation produced by an in-plane heat current in a material with strong spin–orbit coupling.

Magnon: Quantum of collective spin precession in a magnet, carrying energy and angular momentum.

Spin current: Flow of spin angular momentum without net charge transfer, which can be carried by electrons or magnons.

Anomalous Ettingshausen effect: Thermally induced transverse heat flow in a ferromagnet under an applied charge current and magnetisation.

References

1. Enhancement of Transverse Thermoelectric Conversion by Interface‐Induced Spin Current in Ferromagnetic Metal/Nonmagnetic Insulator Hybrid‐Structure. Advanced Functional Materials (2024).
2. Vector spin Seebeck effect and spin swapping effect in antiferromagnetic insulators with non-collinear spin structure. APL Materials (2023).
3. Observation of transverse spin Nernst magnetoresistance induced by thermal spin current in ferromagnet/non-magnet bilayers. Nature Communications (2017).
4. Magneto-optical painting of heat current. Nature Communications (2020).
5. Spin Nernst effect in a p-band semimetal InBi. New Journal of Physics (2020).