Spinström

Spinström, from Swedish meaning “spin current,” is a concept in condensed matter physics and spintronics describing the flow of spin angular momentum in a material without necessarily large net electric charge transport. In practice, it refers to a nonzero transport of spin polarization carried by electrons, which can propagate over a characteristic spin-diffusion length before relaxing.

Spinström can be generated by electrical spin injection, optical spin orientation, or thermally driven processes such as the spin Seebeck effect. In materials with strong spin-orbit coupling, spinström can be converted into a measurable charge signal via the inverse spin Hall effect, enabling electrical detection of the spin flow and its direction.

Detection and characterization rely on a range of techniques. Nonlocal magnetoresistance measurements, spin-pumping experiments, and time-resolved Kerr or Faraday rotation are commonly used to infer the presence and properties of spinström. Materials studied include ferromagnetic metals, semiconductors, magnetic insulators, topological insulators, and two-dimensional materials, where interface quality and material purity strongly influence spin transport.

Applications envisioned for spinström phenomena include nonvolatile memory, spin-based logic, and high-sensitivity magnetometry. Research focuses on understanding spin relaxation mechanisms, coherence times, and efficient spin-to-charge conversion, with ongoing efforts to extend spin-diffusion lengths and optimize materials and device geometries for practical spintronic technologies.

In Swedish-language literature, spinström is frequently used as the translation of “spin current”; in English-language contexts, the term spin current is more common, with spinström used primarily in discussions targeting Swedish audiences.