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Nonlocal Spin Transport as a Probe of Viscous Magnon Fluids
Camilo Ulloa1, A Tomadin2, J Shan3
1Institute for Theoretical Physics, Utrecht University, Princetonplein 5, 3584 CC Utrecht, Netherlands.
Physical Review Letters
|October 2, 2019
Summary
Magnons exhibit fluid-like behavior in ferromagnets. Viscosity in this magnon fluid regime causes a detectable sign change in nonlocal resistance, revealing new insights into spin transport dynamics.
Area of Science:
- Condensed Matter Physics
- Spintronics
- Magnonics
Background:
- Magnons, the quanta of magnetic excitations in ferromagnets, exhibit complex behaviors.
- Understanding magnon dynamics is crucial for advancing spintronic devices and information processing.
Purpose of the Study:
- To theoretically investigate the hydrodynamic regime of magnons in ferromagnets.
- To explore the influence of viscosity on magnon chemical potential and nonlocal resistance.
- To establish nonlocal magnon spin transport devices as a platform for studying fluid dynamics.
Main Methods:
- Theoretical analysis of magnon behavior in the hydrodynamic regime.
- Application of quasiconservation laws for momentum and spin in a magnon fluid.
- Solving equations for nonlocal spin transport in devices with metallic leads.
Main Results:
- Viscous effects in the hydrodynamic regime lead to a sign change in the magnon chemical potential.
- A corresponding sign change in nonlocal resistance is predicted, observable at specific injector-detector distances.
- Finite viscosity results in a magnon backflow phenomenon near the injector lead.
Conclusions:
- Nonlocal resistance measurements can detect the hydrodynamic behavior of magnons.
- Magnon fluid dynamics offer a new perspective on spin transport phenomena.
- Nonlocal magnon spin transport devices are promising for exploring fluid dynamics in magnetic systems.
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