Giant spin torque in systems with anisotropic exchange interaction

TL;DR

This paper demonstrates that anisotropic exchange interaction significantly enhances spin torque in ferromagnet/semiconductor systems, enabling low-current control of magnetic domain walls for advanced memory devices.

Contribution

It reveals that anisotropic exchange interaction between heavy holes and magnetic moments greatly increases current-induced torque, allowing domain wall control at lower current densities.

Findings

Anisotropic exchange interaction boosts spin torque.

Low current density (10^4 A/cm^2) can control domain walls.

Facilitates integration of ferromagnetism into semiconductor electronics.

Abstract

Control of magnetic domain wall movement by the spin-polarized current looks promising for creation of a new generation of magnetic memory devices. A necessary condition for this is the domain wall shift by a low-density current. Here I show that a strongly anisotropic exchange interaction between mobile heavy holes and localized magnetic moments enormously increases the current-induced torque on the domain wall as compared to systems with isotropic exchange. This enables one to control the domain wall motion by current density 10^4 A/cm^2 in ferromagnet/semiconductor hybrids. The experimental observation of the anisotropic torque will facilitate the integration of ferromagnetism into semiconductor electronics