Vortex dynamics in a spin valve nanopillar having hybrid polarizer and magnetostatic coupling

Abstract

This study investigates the observation and control of vortex gyration in the free layer by utilizing polarized current. Modifying the current alone proves challenging in adjusting the frequency and amplitude, as the orbit radius of the vortex core remains constant. To address this, a spin valve nanopillar model with hybrid polarizer is introduced and analyzed, enabling support and gyration of the vortex core in the nanodisk under spin polarized current. Manipulating current density and fine-tuning of hybrid polarizer parameters adjusts system frequency and amplitude. However, with hybrid polarizer, while vortex gyration and higher-frequency signal production increase at higher current densities, the amplitude generally decreases. To mitigate this behavior, the study explores the vortex interactions influenced by magnetostatic coupling in the free layers of spin valve nanopillar. The objective of this paper is to advance the understanding of vortex physics for applications that require greater amplitude microwave signals.