Generation of Pure Spin Current with Insulating Antiferromagnetic Materials

TL;DR

This paper introduces a new method to generate pure spin currents using mechanical stress on insulating antiferromagnetic materials, offering a robust alternative to existing techniques for spintronic devices.

Contribution

It develops a first-principles approach and high-throughput screening to identify materials with significant piezospintronic effects, revealing dominant ionic displacement contributions.

Findings

Identified FeOOH, Cr2O3, and NaMnX as promising materials for piezospintronic effects.

Developed a classification of magnetic point groups enabling pure piezospintronic effects.

Found ionic displacement dominates the piezospintronic effect, unlike piezoelectricity.

Abstract

The generation of pure spin currents is critical for low-dissipation spintronic applications, yet existing methods relying on spin-orbit coupling or ferromagnetic interfaces face challenges in material compatibility and operational robustness. We propose a paradigm-shifting approach to generate symmetry-protected pure spin currents by applying mechanical stress on insulating antiferromagnetic materials, i.e., the pure piezospintronic effect. We first classify magnetic point groups enabling pure piezospintronic effects. A novel first-principles method is developed to compute the spin dipole moments and coefficients of the piezospintronic effect. Integrating these methodologies with high-throughput screening, we identify FeOOH, Cr2O3 and NaMnX (X=As, Bi, P, Sb) with significant pure piezospintronic effects. Interestingly, we reveal that the ionic displacement contribution dominates the piezospintronic effect, in contrast to the piezoelectric effect. Our study not only provides first-principles approach for investigating spin dipole moment related phenomena (e.g., ferrotoroidicity, fractional quantum spin dipole moment, piezospintronics), but also provide promising piezospintronic materials for experimental verification and industrial applications.