Spin-transfer-assisted Parametric Pumping of Magnons in Yttrium Iron Garnet

Therese Frostad, Hans Skarsvåg, Arne Brataas

Published 2022-02-07Version 1

The combination of parametric pumping and spin-transfer torque is a powerful approach that enables high-level control over magnetic excitations in thin-film ferromagnets. The excitation parameters, such as pumping power and external field strength, affect the instabilities of individual magnon modes. We theoretically explore how the simultaneous effects of parametric pumping and spin transfer torque influence these magnetic instabilities in a thin-film ferromagnet. Within the LLG framework, we perform micromagnetic simulations of magnon excitations in yttrium iron garnet by pumping, spin transfer torque, and a combining the two. Consistent with experimental results, we find that the magnitude and direction of the spin transfer torque tune the parametric instability thresholds.