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Updated: Jan 29, 2026

Demonstration of Spin-Multiplexed and Direction-Multiplexed All-Dielectric Visible Metaholograms
Published on: September 25, 2020
Spin-Wave Amplification and Lasing Driven by Inhomogeneous Spin-Transfer Torques
R J Doornenbal1, A Roldán-Molina2, A S Nunez3
1Institute for Theoretical Physics, Utrecht University, Leuvenlaan 4, 3584 CE Utrecht, Netherlands.
Abstract:
We show that an inhomogeneity in the spin-transfer torques in a metallic ferromagnet under suitable conditions strongly amplifies incoming spin waves. Moreover, at nonzero temperatures the incoming thermally occupied spin waves will be amplified such that the region with inhomogeneous spin-transfer torques emits spin waves spontaneously, thus constituting a spin-wave laser. We determine the spin-wave scattering amplitudes for a simplified model and setup, and show under which conditions the amplification and lasing occurs. Our results are interpreted in terms of a so-called black-hole laser, and could facilitate the field of magnonics, which aims to utilize spin waves in logic and data-processing devices.
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