Dynamics of thin-film spin-flip transistors with perpendicular source-drain magnetizations

TL;DR

This paper investigates the magnetization dynamics of thin-film spin-flip transistors with perpendicular source-drain magnetizations, revealing GHz frequency steady-state rotations tunable by bias, with implications for high-frequency nanodevices.

Contribution

It introduces a detailed analysis of the dc-current-driven magnetization dynamics in lateral spin-flip transistors with perpendicular magnetizations, including effects like spin flip scattering and spin pumping.

Findings

Steady-state magnetization rotation at GHz frequencies.

Rotation frequency tunable by source-drain bias.

Potential for high-frequency nanomechanical actuation.

Abstract

A "spin-flip transistor" is a lateral spin valve consisting of ferromagnetic source drain contacts to a thin-film normal-metal island with an electrically floating ferromagnetic base contact on top. We analyze the \emph{dc}-current-driven magnetization dynamics of spin-flip transistors in which the source-drain contacts are magnetized perpendicularly to the device plane by magnetoelectronic circuit theory and the macrospin Landau-Lifshitz-Gilbert equation. Spin flip scattering and spin pumping effects are taken into account. We find a steady-state rotation of the base magnetization at GHz frequencies that is tuneable by the source-drain bias. We discuss the advantages of the lateral structure for high-frequency generation and actuation of nanomechanical systems over recently proposed nanopillar structures.