Charge to spin conversion in atomically thin bismuth

TL;DR

This study demonstrates charge-to-spin conversion in a novel atomically thin bismuth heterostructure with significant in-plane spin polarization, advancing spintronic applications.

Contribution

It reports the first observation of charge-to-spin conversion in atomically thin bismuth within a hybrid heterostructure, highlighting enhanced in-plane spin polarization.

Findings

Charge-to-spin conversion confirmed in Bi heterostructure.

In-plane spin polarization is 3.75 times higher than in control samples.

Weak antilocalization indicates strong spin-orbit coupling.

Abstract

We report charge to spin conversion in a hybrid heterostructure comprised of atomically thin bismuth (Bi) confined between a silicon carbide (SiC) substrate and epitaxial graphene (EG). We confirm composition, dimensionality, and a 96.5 \% intercalation coverage using X-ray photolectron spectroscopy, scanning transmission microscopy, low energy electron diffraction, and Raman spectroscopy. Electrical transport measurements show signs of weak antilocalization in the heterostructure, consistent with spin-orbit coupling in this hybrid heterostructure. Spin torque ferromagnetic resonance measurements in permalloy/EG/2D-Bi heterostructures probe charge-to-spin conversion and revealing that an in plane polarization of the spin current, perpendicular to the charge current. The ratio of the in-plane to out-of-plane torque is 3.75 times higher than in hydrogenated graphene control samples.