Anisotropic superexchange through nonmagnetic anions with spin-orbit coupling

TL;DR

This paper demonstrates that spin-orbit coupling on nonmagnetic anions can induce anisotropic superexchange interactions, revealing a new pathway for realizing exotic magnetic phases and quantum information devices.

Contribution

It analytically shows that nonmagnetic anions with spin-orbit coupling can contribute to anisotropic superexchange, expanding the understanding of magnetic interactions.

Findings

Spin-orbit coupling on nonmagnetic anions induces Dzyaloshinskii-Moriya interaction.

Nonmagnetic anions contribute to symmetric anisotropic exchange.

Potential applications in quantum materials and magnetic devices.

Abstract

Anisotropic superexchange interaction is one of the most important interactions in realizing exotic quantum magnetism, which is traditionally regarded to originate from magnetic ions and has no relation with the nonmagnetic ions. In our work, by studying a multi-orbital Hubbard model with spin-orbit coupling on both magnetic cations and nonmagnetic anions, we analytically demonstrate that the spin-orbit coupling on nonmagnetic anions alone can induce antisymmetric Dzyaloshinskii-Moriya interaction, symmetric anisotropic exchange and single ion anisotropy on the magnetic ions and thus it actually contributes to anisotropic superexchange on an equal footing as that of magnetic ions. Our results promise one more route to realize versatile exotic phases in condensed matter systems, long-range orders in low dimensional materials and switchable single molecule magnetic devices for recording and manipulating quantum information through nonmagnetic anions.