Multiferroics seen from theoretic derivation of a tight binding model

TL;DR

This paper derives a detailed tight binding model for multiferroics from a non-relativistic Hamiltonian, emphasizing the role of electron correlations and spin-orbit coupling in coupling magnetic and electric orders.

Contribution

It provides the first detailed theoretical derivation of a tight binding model for multiferroics from fundamental principles.

Findings

Both ferromagnetism and ferroelectricity originate from electron correlation effects.

Magnetic and electric orders are strongly coupled via spin-orbit interaction.

The model highlights the importance of correlation effects in multiferroic behavior.

Abstract

One presented some lattice models, while the theoretic derivation has not been found, and the importance of correlation effects has to be emphasized. On the basis of the non-relativistic Hamiltonian from the Dirac equation, we derive in detail a tight binding model. We find that both ferromagnetism and ferroelectricity are from the correlation effect between electrons, and magnetic and electric orders are strongly coupled due to the spin-orbit interaction.