A note on the deformation of 1D ferromagnetic domain walls due to double exchange interaction with a free electron gas

TL;DR

This paper investigates how double exchange interactions with a free electron gas influence the shape and conductance of 1D ferromagnetic domain walls, revealing conditions that favor thin or wide walls and their electronic properties.

Contribution

It introduces a S-matrix based method to analyze the deformation and conductance of magnetic domain walls under double exchange interaction in a one-dimensional system.

Findings

Domain walls deform to thin or wide depending on chemical potential and magnetic interaction strength.

Conductance decreases monotonically as domain walls become narrower.

Single and double wall configurations show similar thermodynamic and conductance behavior.

Abstract

Using an S-matrix formulation we evaluate the thermodynamic potential and conductance of a Bloch or N\'eel magnetic wall interacting with a one dimensional free electron gas via a double exchange interaction. The minimization of the elastic magnetic energy plus electronic thermodynamic potential indicates that for chemical potential larger than the magnetic interaction the domain wall is generally deformed to a thin wall, while for magnetic interaction larger than the chemical potential tends towards wide walls. In contrast, for a double wall configuration the deformation is always towards wide walls. For the single as well as the double magnetic wall configurations the conductance monotonically decreases with decreasing wall width. The thermodynamic potential and conductance of Bloch and N\'eel magnetic domain walls are identical within this prototype model.