Magnetic Properties and Spin Dynamics in Ferromagnetic Semiconductors

Ferromagnetic semiconductors combine semiconducting functionality with long-range magnetic order, enabling electrical control of electron spin. Research into their magnetic properties and spin dynamics centres on intrinsic parameters such as Curie temperature, magnetocrystalline anisotropy, exchange interactions and spin–orbit coupling. Tailoring magnetic anisotropy through chemical doping, strain engineering and heterostructure design permits precise control of magnetisation orientation, exchange bias and spin relaxation processes. Spin–orbit torques, arising from spin–charge interconversion, offer non-volatile and high-speed manipulation of magnetic states at low current densities. Spatiotemporal studies of spin dynamics investigate relaxation times, precessional modes and effective damping, informing the design of ultrafast spin-based devices. Gate-tunability, interface-induced phenomena and hybrid architectures aim to elevate operating temperatures towards ambient conditions. Momentum-resolved spectroscopy and time-resolved optical methods have begun to reveal spin-wave propagation and coherence, signalling pathways to magnonic technologies. Progress in this field promises transformative applications in memory, logic and quantum devices, integrating seamlessly with established semiconductor platforms.

Research from Nature Portfolio

Recent studies have demonstrated highly efficient current-driven magnetisation switching in single layers of perpendicularly magnetised GaMnAs, achieving full spin-orbit torque reversal at current densities two orders of magnitude lower than in metallic bilayers, attributed to intrinsic bulk inversion asymmetry and high spin polarisation. A novel field-scan planar Hall measurement technique has been introduced to quantify spin-orbit-induced effective fields in GaMnAs films with in-plane anisotropy, revealing a linear dependence on current density and confirming consistency with angular analysis methods. In quaternary semiconductor bilayers with orthogonal easy axes, pronounced exchange-bias-like shifts of magnetic hysteresis loops have been observed, highlighting robust ferromagnetic coupling and controlled domain formation as tools for tailoring spin configurations.

Magnetic Properties and Spin Dynamics in Ferromagnetic Semiconductors publication trend

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

Technical terms

Ferromagnetic semiconductor: A material that exhibits both semiconducting behaviour and long-range ferromagnetic order.

Spin–orbit torque (SOT): A torque on the magnetisation arising from spin–orbit coupling and an applied electric current, enabling current-induced switching.

Magnetocrystalline anisotropy: The dependence of magnetic energy on the orientation of magnetisation with respect to the crystal lattice.

Exchange bias: A shift in the magnetic hysteresis loop caused by coupling between layers with different magnetic anisotropies.

Planar Hall effect (PHE): The generation of a transverse voltage in a ferromagnetic film when current and magnetic field lie in the same plane.

Curie temperature: The temperature above which a ferromagnetic material loses its spontaneous magnetisation.

Spin dynamics: The study of time-dependent behaviour of spin precession, relaxation and transfer in magnetic materials.

References

1. Electric Field Control of Spin–Orbit Torque Magnetization Switching in a Spin–Orbit Ferromagnet Single Layer. Advanced Science (2023).
2. Investigation of orthogonal spin–orbit fields in crystalline ferromagnetic films with four-fold in-plane magnetic anisotropy. APL Materials (2023).
3. Efficient full spin–orbit torque switching in a single layer of a perpendicularly magnetized single-crystalline ferromagnet. Nature Communications (2019).
4. Spin–orbit torque switching in a single (Ga,Mn)(As,P) layer with perpendicular magnetic anisotropy. APL Materials (2021).
5. Quantitative determination of spin–orbit-induced magnetic field in GaMnAs by field-scan planar Hall measurements. Scientific Reports (2021).
6. Exchange bias in ferromagnetic bilayers with orthogonal anisotropies: the case of GaMnAsP/GaMnAs combination. Scientific Reports (2019).