Controllable vortex shedding from dissipative exchange flows in ferromagnetic channels

Iacocca, Ezio (2020) Controllable vortex shedding from dissipative exchange flows in ferromagnetic channels. Physical Review B, 102 (22). p. 224403. ISSN 2469-9950

[img]
Preview
Text
Controllable vortex shedding from dissipative exchange flows in ferromagnetic channels Accepted.pdf - Accepted Version

Download (1MB) | Preview
Official URL: https://doi.org/10.1103/physrevb.102.224403

Abstract

Ferromagnetic channels subject to spin injection at one extremum sustain long-range coherent textures that carry spin currents known as dissipative exchange flows (DEFs). In the weak injection regime, spin currents carried by DEFs decay algebraically and extend through the length of the channel, a regime known as spin superfluidity. Similar to fluids, these structures are prone to phase slips that manifest as vortex-antivortex pairs. Here, we numerically study vortex shedding from DEFs excited in a magnetic nanowire with a physical obstacle. Using micromagnetic simulations, we find regimes of laminar flow and vortex shedding as a function of obstacle position tunable by the spin injection sign and magnitude. Vortex-antivortex pairs translate forward (VF regime) or backward (VB regime) with respect to the detector's extremum, resulting in well-defined spectral features. Qualitatively similar results are obtained when temperature, anisotropy, and weak nonlocal dipole fields are included in the simulations. These results provide clear features associated with DEFs that may be detected experimentally in devices with nominally identical boundary conditions. Furthermore, our results suggest that obstacles can be considered as DEF control gates, opening an avenue to manipulate DEFs via physical defects.

Item Type: Article
Subjects: F300 Physics
Department: Faculties > Engineering and Environment > Mathematics, Physics and Electrical Engineering
Depositing User: Elena Carlaw
Date Deposited: 08 Jan 2021 12:09
Last Modified: 08 Jan 2021 12:15
URI: http://nrl.northumbria.ac.uk/id/eprint/45171

Actions (login required)

View Item View Item

Downloads

Downloads per month over past year

View more statistics