Spintronics in Semiconductors

Spintronics, or spin-based electronics, exploits the intrinsic angular momentum of electrons in addition to their charge. In semiconductors, the ability to generate, manipulate and detect spin-polarised carriers within a host crystal lattice offers routes to non-volatile memory, reconfigurable logic and quantum information processing. Central challenges include efficient spin injection across ferromagnet–semiconductor interfaces, preservation of spin coherence over practical device lengths and tunable spin–orbit interactions. Various materials platforms have been explored, including conventional group IV semiconductors such as silicon and germanium, compound semiconductors, alloyed systems and hybrid structures incorporating Heusler compounds or oxide layers. Progress in epitaxial growth, interface engineering and heterostructure design has enabled room-temperature operation of spin valves, spin field-effect transistors and pure spin-current devices. The interplay between electric fields, quantum confinement and magnetic proximity effects allows dynamic control of spin transport, while advanced detection schemes based on the Hanle effect and the inverse spin-Hall effect offer detailed insight into spin lifetimes and diffusion lengths. Such capabilities underpin emerging technological paradigms in ultra-low power computing, high-density data storage and scalable quantum networks.

Research from Nature Portfolio

Recent studies have elucidated the magnetic proximity effect at metal–silicon interfaces, demonstrating that semiconductor doping can invert the alignment of induced magnetisation relative to an adjacent ferromagnetic layer. This finding highlights the role of electron tunnelling and exchange splitting in tailoring interface magnetism for device integration. Investigations into germanium quantum wells have achieved long spin lifetimes and shown that quantum confinement can be used to engineer the electron Landé g factor across a technologically relevant range, offering a pathway to spin qubit control in a CMOS-compatible platform. Work on lateral semiconductor spin valves has revealed large, electric-field-tunable magnetoresistance at room temperature by exploiting finite electric fields at the contact interface to enhance spin-to-charge conversion, enabling up to eighty per cent resistance change without relying on strong spin–orbit coupling.

Research from all publishers

Novel oxide-based planar spin-valve devices incorporating an artificial nanometre-scale Mott-insulator barrier have achieved magnetoresistance ratios exceeding 140 per cent, far surpassing conventional semiconductor counterparts, and demonstrated current modulation fundamental to spin-transistor operation. Epitaxial alloys of germanium–tin have been shown to support room-temperature spin current emission and detection through spin-pumping ferromagnetic resonance, with spin-mixing conductance and Gilbert damping exhibiting non-monotonic dependence on alloy composition. A complementary approach employs non-local architectures in doped bulk silicon, where optically injected spins are manipulated and detected via the inverse spin-Hall effect; the spin transport length can be modulated by over 100 per cent through applied electric fields, illustrating tunable drift versus diffusion regimes in silicon platforms.

Spintronics in Semiconductors publication trend

The graph below shows the total number of articles in spintronics in semiconductors across all publications each year (not limited to Nature Index journals).

Technical terms

Spin current: Flow of spin angular momentum without net charge transport.

Spin injection: Transfer of spin-polarised carriers from a ferromagnet into a semiconductor.

Spin diffusion length: Mean distance over which a non-equilibrium spin population maintains coherence.

Spin pumping: Generation of spin current by dynamic excitation of a magnetic layer.

Schottky barrier: Energy barrier at a metal–semiconductor junction affecting carrier and spin injection.

Inverse spin-Hall effect: Conversion of a transverse spin current into a measurable charge voltage.

Hanle effect: Dephasing and precession of spin populations under a transverse magnetic field, used for lifetime measurements.

References

1. Giant Spin‐Valve Effect in Planar Spin Devices Using an Artificially Implemented Nanolength Mott‐Insulator Region. Advanced Materials (2023).
2. Doping dependent intrinsic magnetization in silicon in Ni/Si heterostructures. Scientific Reports (2024).
3. Spin Pumping in Epitaxial Ge1‐xSnx Alloys. Advanced Quantum Technologies (2024).
4. Non-local architecture for spin current manipulation in silicon platforms. APL Materials (2023).
5. Gate-tunable large magnetoresistance in an all-semiconductor spin valve device. Nature Communications (2017).
6. Strong confinement-induced engineering of the g factor and lifetime of conduction electron spins in Ge quantum wells. Nature Communications (2016).