Stabilization of a nonlinear bullet coexisting with a Bose-Einstein condensate in a rapidly cooled magnonic system driven by a spin-orbit torque

Abstract

We have recently shown that injection of magnons into a magnetic dielectric via the spin-orbit torque (SOT) effect in the adjacent layer of a heavy metal subjected to the action of short (0.1 $\mu$s) current pulses allows for control of a magnon Bose-Einstein Condensate (BEC). Here, the BEC was formed in the process of rapid cooling (RC), when the electric current heating the sample is abruptly terminated. In the present study, we show that the application of a longer (1.0 $\mu$s) electric current pulse triggers the formation of a nonlinear localized magnonic bullet below the linear magnon spectrum. After pulse termination, the magnon BEC, as before, is formed at the bottom of the linear spectrum, but the nonlinear bullet continues to exist, stabilized for additional 30 ns by the same process of RC-induced magnon condensation. Our results suggest that a stimulated condensation of excess magnons to all highly populated magnonic states occurs.

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Cited by in corpus (8)

• Stimulated amplification of propagating spin waves
• Modeling of the micro-focused Brillouin light scattering spectra
• Anisotropy-assisted magnon condensation in ferromagnetic thin films
• Non-local magnon transconductance in extended magnetic insulating films.\\ Part I: spin diode effect
• Local temperature control of magnon frequency and direction of supercurrents in a magnon Bose-Einstein condensate
• Non-local magnon transconductance in extended magnetic insulating films.\\Part II: two-fluid behavior
• Enhancement of magnon flux toward a Bose-Einstein condensate
• Spin-wave emission with current-controlled frequency by a PMA-based spin-Hall oscillator