Controlling magnon interaction by a nanoscale dipole switch

The ability to control and tune magnetic dissipation is a key concept of emergent spintronic technologies. Magnon scattering processes [1,2] constitute a major dissipation channel in nanomagnets, can redefine their response to spin-torques, and hold the promise for manipulating magnetic states on the quantum level. Controlling these processes, while being imperative for spintronic applications, has remained difficult to achieve. Here, we propose an approach for controlling magnon scattering by a nanoscale dipole switch. We demonstrate an experimental proof-of-concept in magnetic tunnel junction nanodevices. By triggering the spin-flop transition in the synthetic antiferromagnet layers and utilizing their dipole field, a three-magnon process in the free layer is toggled. The switching of the synthetic antiferromagnet tunes the strength of the magnon interaction by at least one order of magnitude, leading to two distinct dissipative states. The results allow for controlling dissipation by external stimuli at nanoscale and show promise for spin-torque applications and hybrid quantum information technologies.
[1] Barsukov et al., Sci. Adv. 5, eaav6943 (2019)
[2] Navabi et al., Phys. Rev. Appl. 11, 034046 (2019)