Details

Autor(en) / Beteiligte

• Ulloa, Camilo
• Tomadin, A.
• Shan, J.
• Polini, M.
• van Wees, B. J.
• Duine, R. A.

Titel

Nonlocal Spin Transport as a Probe of Viscous Magnon Fluids

Ist Teil von

• Physical review letters, 2019-09, Vol.123 (11), p.1, Article 117203

Ort / Verlag

College Park: American Physical Society

Erscheinungsjahr

2019

Quelle

PROLA

Beschreibungen/Notizen

• Magnons in ferromagnets behave as a viscous fluid over a length scale, the momentum-relaxation length, below which momentum-conserving scattering processes dominate. We show theoretically that in this hydrodynamic regime viscous effects lead to a sign change in the magnon chemical potential, which can be detected as a sign change in the nonlocal resistance measured in spin transport experiments. This sign change is observable when the injector-detector distance becomes comparable to the momentum-relaxation length. Taking into account momentum- and spin-relaxation processes, we consider the quasiconservation laws for momentum and spin in a magnon fluid. The resulting equations are solved for nonlocal spin transport devices in which spin is injected and detected via metallic leads. Because of the finite viscosity we also find a backflow of magnons close to the injector lead. Our work shows that nonlocal magnon spin transport devices are an attractive platform to develop and study magnon-fluid dynamics.