Dzyaloshinskii-Moriya Interaction-Induced Magnetoelectric Coupling in a tetrahedral Molecular Spin-Frustrated System

TL;DR

This study explores how Dzyaloshinskii-Moriya interactions induce magnetoelectric coupling in a tetrahedral molecular spin system, revealing emergent electric dipoles linked to non-collinear spins and quantifiable via susceptibility calculations.

Contribution

It demonstrates the emergence of electric dipoles from spin orderings in a molecular magnet due to Dzyaloshinskii-Moriya interactions, providing a theoretical framework for magnetoelectric coupling in such systems.

Findings

Electric dipole moments emerge with non-collinear spin orderings.

Magnetoelectric coupling can be quantified through susceptibilities.

Quadratic relations are observable in experiments.

Abstract

We have investigated magnetoelectric coupling in the single-molecule magnet $\mathrm{Mn}_{4}\mathrm{Te}_{4}(\mathrm{P}\mathrm{Et}_{3})_{4}$ with tetrahedral spin frustration. Our density functional studies found that an electric dipole moment can emerge with various non-collinear spin orderings. The forms of spin-dependent dipole are determined and consistent with that in non-centrosymmetric magnets driven by the Dzyaloshinskii-Moriya interaction. Writing a parameterized spin Hamiltonian, after solving for eigenvalues and eigenstates we quantified the magnetoelectric coupling by calculating the thermal average of the electric and magnetic susceptibilities, which can be influenced by external magnetic and electric fields, respectively. The quadratic relations are expected to be observable in experiments.