Microscopic origin of Magnetic Ferroelectrics in Nonlinear Multiferroics

TL;DR

This paper proposes a microscopic mechanism explaining the interplay between magnetic and electric properties in nonlinear multiferroics, linking magnetic structures to electric polarization through spin-orbital coupling.

Contribution

It introduces a general microscopic model connecting magnetic structures to electric polarization via spin-orbital interactions, predicting material properties like half insulator behavior.

Findings

Electric polarization is determined by a single spin-orbital coupling parameter.

The mechanism predicts materials to be half insulators.

Provides estimates and physical limitations for ferroelectricity.

Abstract

A simple but general microscopic mechanism to understand the interplay between the electric and magnetic degrees of freedom is developed. Within this mechanism, the magnetic structure generates an electric current which induce an counterbalance electric current from the spin orbital coupling. When the magnetic structure is described by a single order parameter, the electric polarization is determined by the single spin orbital coupling parameter, and the material is predicted to be a half insulator. This mechanism provides a simple estimation of the value of ferroelectricity and sets a physical limitation as well.