Spin filtration in a single-stranded antiferromagnetic helix with slowly varying disorder: Higher order electron hopping

Abstract

This work explores spin filtration in a helical magnetic system within a tight-binding framework, where neighboring magnetic moments are aligned antiparallel. The helix experiences a slowly-varying diagonal disorder, following a cosine form, which creates a finite energy mismatch between up and down spin channels. Unlike earlier studies that relied on external electric fields, this investigation demonstrates that disorder alone can achieve high spin filtration, even at low bias and high temperatures. Higher-order electron hopping in the helix leads to a non-uniform energy level distribution, facilitating favorable spin filtration, sometimes reaching $100\%$. The interplay between higher-order hopping and atypical disorder may enable selective spin transmission through various antiferromagnetic helices, potentially opening new avenues for functional elements.