Spintronics and Spin Dynamics in Semiconductor Nanostructures

Spintronics exploits the electron’s spin degree of freedom alongside its charge for information processing, offering prospects for devices with enhanced speed, lower power consumption and novel functionality. Semiconductor nanostructures—quantum wells, wires and dots—provide versatile platforms in which spin lifetimes, coherence and transport distances can be engineered through quantum confinement, material composition and applied fields. Central to this field are spin–orbit interactions, which couple spin orientation to carrier momentum via Rashba and Dresselhaus mechanisms. When balanced, these interactions can give rise to a persistent spin helix, a long‐lived spin pattern that propagates without decay. The manipulation of spins in motion—so called “flying spins”—and the control of spin relaxation by symmetry tuning or external perturbations have become defining achievements. Advances in heterostructure growth, surface acoustic‐wave technology and photonic microcavities now allow dynamic, contactless gating of spin precession, as well as the spatial separation, coherent transport and electrical modulation of spin currents. These developments influence quantum information schemes, spin‐based logic and on‐chip photonic interfaces, underlining the global significance of spin dynamics in semiconductor nanostructures.

Research from Nature Portfolio

Dynamic control of moving electron spins has been demonstrated by using surface acoustic waves to trap and transport spins in semiconductor quantum dots. The strain field accompanying the wave acts as a moving, contactless gate that tunes spin–orbit coupling and thus the precession frequency of the “flying” spins, achieving an order‐of‐magnitude improvement in precession control. In two‐dimensional Rashba systems, ballistic electrons have been shown to undergo controlled spin rotation via orbital motion, overcoming the traditional locking of spin orientation to momentum and opening routes to spin‐phase engineering in solid‐state channels. Additionally, drift transport of a persistent spin helix in a two‐dimensional electron gas has been achieved without external magnetic fields: by tailoring Rashba and Dresselhaus interactions to match, spatial coherence of drifting spins is maximized and their transport length extended, while time‐varying in‐plane voltages allow precise modulation of the spin trajectory.

Research from all publishers

A purely optical realisation of a persistent spin helix and a photonic analogue of Stern–Gerlach deflection has been achieved in an anisotropic liquid‐crystal microcavity. This work reproduces the SU(2) symmetry of Rashba–Dresselhaus Hamiltonians for confined photons, producing spatial oscillations in photon polarisation that mirror electronic spin‐helix patterns. In bulk‐Rashba GeTe/NiFe bilayers, a large field‐like spin–orbit torque has been reported, attributed to enhanced interfacial coupling from the bulk Rashba channel. The torque remains robust over a wide ferromagnet thickness range, demonstrating scalable in‐plane spin‐orbit devices and prompting new theoretical challenges in interfacial spin transport.

Spintronics and Spin Dynamics in Semiconductor Nanostructures publication trend

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

Technical terms

Spintronics: The field of research and technology that utilises the electron’s spin degree of freedom, in addition to its charge, for information storage, processing and transmission.

Spin–orbit coupling: An intrinsic interaction in solids where an electron’s motion through an electric field produces an effective magnetic field acting on its spin, key to spin dynamics.

Rashba effect: A type of spin–orbit interaction arising from structural inversion asymmetry in semiconductor heterostructures, leading to momentum‐dependent spin splitting.

Dresselhaus effect: A spin–orbit mechanism present in crystals lacking bulk inversion symmetry, generating a momentum‐dependent effective magnetic field and spin splitting.

Persistent spin helix: A spin density wave, formed when Rashba and Dresselhaus couplings are equal, that exhibits exceptionally long lifetimes and coherence lengths.

Spin–orbit torque: The torque exerted on a magnetic layer by spin currents generated via spin–orbit coupling, enabling electrical manipulation of magnetisation.

References

1. Drift transport of helical spin coherence with tailored spin–orbit interactions. Nature Communications (2016).
2. Spin-momentum locked spin manipulation in a two-dimensional Rashba system. Scientific Reports (2019).
3. Realizing Optical Persistent Spin Helix and Stern-Gerlach Deflection in an Anisotropic Liquid Crystal Microcavity. Physical Review Letters (2021).
4. Flying electron spin control gates. Nature Communications (2022).
5. Field-like spin–orbit torque induced by bulk Rashba channels in GeTe/NiFe bilayers. NPG Asia Materials (2021).