High-Throughput Discovery of Two-Dimensional Materials Exhibiting Strong Rashba-Edelstein effect

TL;DR

This paper systematically analyzes the Rashba-Edelstein effect in 2D materials, identifies high-performance candidates through symmetry analysis and first-principles calculations, and demonstrates their potential for efficient charge-to-spin conversion.

Contribution

It provides a comprehensive symmetry-based framework and screens 54 promising 2D materials with high REE responses, advancing the understanding of charge-to-spin conversion in 2D systems.

Findings

Largest REE response coefficients exceed previous reports by an order of magnitude.

54 promising 2D materials identified with high charge-to-spin conversion efficiency.

Effective kp models explain the large response and spin textures in selected materials.

Abstract

The Rashba-Edelstein effect (REE), which generates spin accumulation under an applied electric current, quantifies charge-to-spin conversion (CSC) efficiency in non-centrosymmetric systems. However, systematic investigations of REE in two-dimensional (2D) materials remain scarce. To address this gap, we perform a comprehensive symmetry analysis based on the 80 crystallographic layer groups, elucidating the relationship between materials' symmetries and the geometric characteristics of the REE response tensor. Our analysis identifies 13 distinct symmetry classes for the tensor and reveals all potential material candidates. Considering the requirement of strong spin-orbit coupling for a large REE response, we screen the C2DB database and identify 54 promising 2D materials. First-principles calculations demonstrate that the largest REE response coefficients in these materials exceed those reported for other 2D systems by an order of magnitude, indicating exceptionally high CSC efficiency. Focusing on three representative materials, including HgI2, AgTlP2Se6 and BrGaTe, we show that their large response coefficients can be well explained by effective kp models and the characteristic spin textures around high-symmetry points in momentum space. This work provides a systematic framework and identifies high-performance candidates, paving the way for future exploration of REE-driven CSC in 2D materials.