CAREER: Nonlinear Magnetization Dynamics Excited by Spin Transfer Torque

University Of California-Irvine, Irvine CA

Investigators

Abstract

****NON-TECHNICAL ABSTRACT**** Electric and magnetic properties of ferromagnetic metals interact with each other but the details of these magneto-electric interactions at short (a few nanometer) distances are not well understood. The goal of this Faculty Early Career Development project is to study new regimes of magneto-electric interactions in very small metallic magnetic objects (nanostructures). In particular, this work will investigate how the energy of magnetic waves in ferromagnetic nanowires is modified by an electric current. A new type of magnetic resonance excited by an electric current will be studied, and the feasibility of using this resonance in a magnetic field nano-sensor for the next generation of computer hard drives will be determined. This project will expose high-school, undergraduate and graduate students to nanoscience and will prepare specialists for the US electronics and magnetic recording industries. Nano-electronic devices made for this project will be used in an interdisciplinary experimental skills class at the University of California at Irvine. ****TECHNICAL ABSTRACT**** Understanding collective dynamics of electronic charge and spin degrees of freedom in itinerant ferromagnets is of great fundamental importance and may lead to the development of a new class of magneto-electronic devices. The goal of this Faculty Early Career Development project is to study new regimes of strongly nonlinear magnetization dynamics excited by spin-polarized current in ferromagnetic nanowires and nanomagnets. This work will advance our understanding of how properties of spin waves in ferromagnetic nanowires evolve from linear to nonlinear regimes and how the spin wave dispersion relation is modified by a spin-polarized current. The role of spin wave spectrum quantization on the Suhl instability phenomenon in nanowires will be determined, and a new type of stochastic resonance excited by spin-polarized current will be studied. This project will expose a number of high-school, undergraduate and graduate students to nanoscience and will prepare specialists for the US electronics and magnetic recording industries. Nano-electronic devices made for this project will be used in an interdisciplinary experimental skills class at the University of California at Irvine.