Strain-modulated magnetization precession in skyrmion-based spin transfer nano-oscillator

Abstract

The magnetic skyrmion-based spin transfer nano-oscillators have been set as microwave signal emitters and gaining in popularity due to their performance and integrability in the existing CMOS process flow. In this work, we report our investigations on the strain-modulated magnetization precession in the breathing mode skyrmion-based spin transfer nano-oscillator, which strains from the juxtaposed piezoelectric materials. The strain-modulated skyrmion breathing frequency can be strongly controlled by biaxial-isotropy in-plane strain, in which the tunable range varies from 500 MHz to 7 GHz under the fixed current density −4 ×1012 A/m2 and varying strain from −2000 ppm to 4000 ppm. Such tunability is external magnetic free and even does not reduce the dynamic resistance variation. Through this method, a promising digital binary frequency shift-key and amplitude shift-key modulation technique are presented, in which the magnetization precession frequency and amplitude can be tuned with the co-action of current and strain pulses. These findings are providing an optional route to design future tunable spin transfer nano-oscillators based on skyrmion with better performance in the wireless communication.