Electric-field-induced parametric excitation of exchange magnons in a CoFeB/MgO junction

TL;DR

This paper demonstrates electric-field induced parametric excitation of exchange magnons in CoFeB/MgO junctions, enabling low-power control of magnetization dynamics for spintronic applications.

Contribution

It introduces a novel electric-field control method for magnon excitation in magnetic junctions, with a developed phenomenological model explaining the electric-field torque effects.

Findings

Magnons are efficiently excited when magnetic anisotropy and magnetic field are aligned.

Wavelength and wavenumber of magnons are tunable via input power and frequency.

Electrical excitation occurs without Joule heating, suitable for low-power magnonic devices.

Abstract

Electric-field controlled magnetization dynamics is an important integrant in low power spintronic devices. In this letter, we demonstrate electric-field induced parametric excitation for CoFeB/MgO junctions by using interfacial in-plane magnetic anisotropy. When the in-plane magnetic anisotropy and the external magnetic field are parallel to each other, magnons are efficiently excited by using electric-field induced parametric excitation. Its wavelength and wavenumber are tuned by changing input power and frequency of the applied voltage. A generalized phenomenological model is developed to explain the underlying role of the electric-field torque. Electrical excitation with no Joule heating offers a good opportunity for developing magnonic devices and exploring various nonlinear dynamics in magnetic systems.