Impact of higher-order electron hopping on spin filtering in an antiferromagnetic helical system with correlated disorder

We investigate spin-selective electron transport in an antiferromagnetic helical system subjected to correlated diagonal disorder within a tight-binding framework. The disorder profile is assumed to vary slowly along the helix through a cosine modulation. In contrast to previously studied mechanisms requiring externally applied electric fields or thermal gradients, the present study demonstrates that correlated disorder can effectively break the symmetry between the two spin sectors, thereby inducing remarkably efficient spin filtering, even under low-bias and high-temperature conditions. We further show that higher-order electron hopping significantly modifies the spectral distribution by producing an uneven arrangement of energy levels, thereby promoting enhanced spin selectivity. Depending on the system parameters, nearly perfect spin polarization can be achieved. The combined effects of long-range hopping and slowly varying disorder suggest a possible route toward controlled spin transport in antiferromagnetic helical conductors, which may be useful for future spintronic functionalities.