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Abstract The search for efficient approaches to realize local switching of magnetic moments in spintronic devices has attracted extensive attention. One of the most promising approaches is the electrical manipulation of magnetization through electron‐mediated spin torque. However, the Joule heat generated via electron motion unavoidably causes substantial energy dissipation and potential damage to spintronic devices. Here, all‐oxide heterostructures of SrRuO3/NiO/SrIrO3are epitaxially grown on SrTiO3single‐crystal substrates following the order of the ferromagnetic transition metal oxide SrRuO3with perpendicular magnetic anisotropy, insulating and antiferromagnetic NiO, and metallic transition metal oxide SrIrO3with strong spin–orbit coupling. It is demonstrated that instead of the electron spin torques, the magnon torques present in the antiferromagnetic NiO layer can directly manipulate the perpendicular magnetization of the ferromagnetic layer. This magnon mechanism may significantly reduce the electron motion‐related energy dissipation from electron‐mediated spin currents. Interestingly, the threshold current density to generate a sufficient magnon current to manipulate the magnetization is one order of magnitude smaller than that in conventional metallic systems. These findings suggest a route for developing highly efficient all‐oxide spintronic devices operated by magnon current.
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Magnonic analog of a metal-to-insulator transition in a multiferroic heterostructure
We show how, by changing the polarization value of ferroelectric domains, it is possible to tune the magnon conductivity in the ferromagnetic film layer of a multiferroic magnonic system. In particular, we suggest how to switch from a metal behavior (zero frequency gap and linear frequency-wavevector dispersion) to an insulator behavior (around 1 GHz frequency gap and parabolic dispersion). The ferroelectric film is prepared with a sequence of ferroelectric domains with a periodic variation of their polarization direction. Through inverse magnetostriction, they induce in the ferromagnetic layer a periodic magnetic anisotropy and a consequent sinusoidal magnetization. The amplitude of the sinusoidal magnetization can be varied by varying the induced magnetic anisotropy. This allows for a fine and reversible control over the curvature of the dispersion relations at the Brillouin zone boundary, as well as the width of the frequency gap. We suggest the extension of Dirac’s magnon picture to our system, finding interesting implications in terms of magnon mobility. This work expands the possible implementations of the voltage-controlled-bandgap meta-materials, marks the conditions for the occurrence of a magnonic metal behavior in a ferromagnetic film, and outlines how a same unpatterned film can be reversibly turned from a magnonic metal to a magnonic insulator.
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- Award ID(s):
- 2205796
- PAR ID:
- 10582912
- Publisher / Repository:
- American Institute of Physics
- Date Published:
- Journal Name:
- Journal of Applied Physics
- Volume:
- 137
- Issue:
- 15
- ISSN:
- 0021-8979
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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