Non-Collinear Ferromagnetic Luttinger Liquids

TL;DR

This paper investigates how a non-collinear ferromagnetic domain wall affects the properties of a one-dimensional interacting electron system, revealing significant changes in excitations and spin-transfer effects due to broken spin-charge separation.

Contribution

It introduces a model of a ferromagnetic domain wall coupled to a Luttinger liquid, showing how non-collinearity and electron interactions alter fundamental excitations and spin dynamics.

Findings

Spin-charge separation is broken by the domain wall.

Electron correlations lead to unique excitation behaviors.

Spin-transfer-torque effects are significantly modified.

Abstract

The presence of electron-electron interactions in one dimension profoundly changes the properties of a system. The separation of charge and spin degrees of freedom is just one example. We consider what happens when a system consisting of a ferromagnetic region of non-collinearity, i.e. a domain wall, is coupled to interacting electrons in one-dimension (more specifically a Luttinger liquid). The ferromagnetism breaks spin charge separation and the presence of the domain wall introduces a spin dependent scatterer into the problem. The absence of spin charge separation and the effects of the electron correlations results in very different behaviour for the excitations in the system and for spin-transfer-torque effects in this model.