Voltage-Controlled Nano-Scale Reconfigurable Magnonic Crystal

TL;DR

This paper presents a nano-scale magnonic crystal whose spin-wave band gaps can be dynamically controlled and switched on or off within nanoseconds using voltage-induced changes in magnetic anisotropy, enabling low-power magnonic devices.

Contribution

It introduces a novel voltage-controlled reconfigurable magnonic crystal based on PMA modulation in ferromagnetic heterostructures, allowing fast and selective control of spin-wave band gaps.

Findings

Voltage application modifies spin-wave spectra and creates tunable band gaps.

Band gaps can be switched on/off within a few nanoseconds.

Selective voltage application enables pre-defined spectral modifications.

Abstract

A nano-scale reconfigurable magnonic crystal is designed using voltage-controlled perpendicular magnetic anisotropy (PMA) in ferromagnetic-dielectric hetero-structures. A periodic array of gate metallic stripes is placed on top of a MgO/Co structure in order to apply a periodic electric field and to modify the PMA in Co. It is numerically demonstrated that the application of the voltage to the gate stripes modifies the spin-wave propagation and leads to the formation of band gaps in the spin-wave spectrum. The band gaps are dynamically controllable, i.e. it is possible to switch band gaps on and off within a few nanoseconds. The width and the center frequency of the band gaps is defined by the applied voltage. At last, it is shown that the application of the voltage to selected, rather than to all gate stripes allows for a pre-defined modification of the band gap spectra. The proposed voltage-controlled reconfigurable magnonic crystal opens a new way to low power consumption magnonic applications.